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WO2024185731A1 - Light diffusion device and medical catheter set provided therewith - Google Patents

Light diffusion device and medical catheter set provided therewith Download PDF

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Publication number
WO2024185731A1
WO2024185731A1 PCT/JP2024/007982 JP2024007982W WO2024185731A1 WO 2024185731 A1 WO2024185731 A1 WO 2024185731A1 JP 2024007982 W JP2024007982 W JP 2024007982W WO 2024185731 A1 WO2024185731 A1 WO 2024185731A1
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WO
WIPO (PCT)
Prior art keywords
light
optical fiber
cladding
diffusion device
tip
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2024/007982
Other languages
French (fr)
Japanese (ja)
Inventor
英明 長谷川
淳一 長谷川
拓朗 山崎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Furukawa Electric Co Ltd
Original Assignee
Furukawa Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Furukawa Electric Co Ltd filed Critical Furukawa Electric Co Ltd
Priority to JP2025505320A priority Critical patent/JPWO2024185731A1/ja
Priority to CN202480016530.7A priority patent/CN120813873A/en
Priority to DE112024001096.2T priority patent/DE112024001096T5/en
Publication of WO2024185731A1 publication Critical patent/WO2024185731A1/en
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
    • A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
    • A61B1/07—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements using light-conductive means, e.g. optical fibres
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
    • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
    • A61B18/22—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor
    • A61B18/24—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser the beam being directed along or through a flexible conduit, e.g. an optical fibre; Couplings or hand-pieces therefor with a catheter
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating

Definitions

  • the present invention relates to a light diffusion device for use in medical equipment and a medical catheter set equipped with the same.
  • a conventional light diffusion device includes an optical fiber consisting of a core located at the center in the radial direction and a cladding located on the outer periphery of the core, and that emits laser light incident on the base end of the optical fiber from the tip end and the outer periphery on the tip side (see, for example, Patent Document 1).
  • the optical fiber of the conventional light diffusion device has a light transmission section that transmits the laser light incident on the base end, and a light emission section at the tip side that emits the laser light transmitted through the light transmission section.
  • Light diffusion devices are used in photoimmunotherapy, a cancer treatment method, by inserting the tip of an optical fiber into the human body and irradiating laser light onto drugs that have been administered to the body and reached the cancer cells. Light diffusion devices are also used by inserting them into the body together with endoscopes such as gastroscopes and catheters to irradiate the inside of the body or project light from inside the body onto its surface.
  • endoscopes such as gastroscopes and catheters
  • Conventional light diffusion devices emit light from the outer surface of the light output section by partially removing the cladding at the tip side of the optical fiber to expose the core.
  • the difference between the refractive index of the core at the light output section and the refractive index of the air located on the outer periphery of the core becomes large, and the light confinement effect becomes stronger.
  • the laser light emitted from the light output section has a limited emission intensity throughout the entire light output section.
  • one of the objectives is to provide a light diffusion device that can efficiently emit light transmitted through a light transmission section in a specific direction on the side, and a medical catheter set equipped with the same.
  • a light diffusing device is a light diffusing device comprising an optical fiber having a core located at a radial center side and a clad located on an outer peripheral side of the core, the light diffusing device causing light incident on a base end of the optical fiber to exit from a tip end side of the optical fiber, a light transmitting section that transmits light incident from a base end section toward a tip end section, and a light emitting section that is formed by removing a portion located on an outer circumferential side of the clad on the tip side,
  • the outer diameter Db of the cladding in the light emitting portion is smaller than the outer diameter Da of the cladding in the light transmitting portion by at least the wavelength ⁇ of the light transmitted through the light transmitting portion (Db ⁇ Da ⁇ ), and
  • the optical fiber has an end face at an angle to a plane perpendicular to the axis of the core at the end on the tip side.
  • the thickness t of the cladding in the light emitting portion may be 1 ⁇ m or more in an area that accounts for 30% or more of the total area of the light emitting portion.
  • the light emitting portion may extend to a region adjacent to the end face at the tip side of the optical fiber.
  • the end face may be continuous in the circumferential direction of the optical fiber, and may have a conical shape.
  • the angle between the end face and a plane perpendicular to the axis of the core may be less than the minimum angle at which light transmitted through the optical transmission section is totally reflected.
  • the optical fiber may be made of resin.
  • the numerical aperture (NA) of the optical fiber may be 0.5 or more.
  • the outer surface of the optical fiber in the light emitting section may be uneven.
  • the medical catheter set according to one aspect of the present invention includes a catheter and the light diffusion device according to one aspect of the present invention.
  • a light diffusion device that can efficiently emit light transmitted through a light transmission section in a specific direction on the side, and a medical catheter set that includes the same.
  • FIG. 1 is a schematic diagram of a light diffusing device according to a first embodiment which is an exemplary aspect of the present invention.
  • 5 is a cross-sectional view of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment and a main portion in the vicinity thereof, taken along the line AA in FIGS. 3 and 4.
  • FIG. 3 is a cross-sectional view of a portion of a light transmitting portion of an optical fiber in the light diffusing device according to the first embodiment, taken along the CC cross section in FIG. 2.
  • 3 is a cross-sectional view of a portion of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment, taken along the line DD in FIG. 2.
  • FIG. 3 is an enlarged horizontal cross-sectional view of a main part of a light emitting portion of an optical fiber in the light diffusing device according to the first embodiment.
  • FIG. 3 is an enlarged cross-sectional view of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment and its vicinity.
  • FIG. 2 is an enlarged perspective view of a light exit portion of an optical fiber and its vicinity in the light diffusing device according to the first embodiment;
  • FIG. 11 is a cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a second embodiment and a main portion in the vicinity thereof.
  • FIG. 11 is an enlarged cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a second embodiment and its vicinity.
  • FIG. 13 is a plan view of a light diffusing device according to a second embodiment, as viewed from the tip side of an optical fiber.
  • FIG. 13 is a cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a third embodiment and its vicinity.
  • FIG. 13 is an enlarged cross-sectional view of a light exit portion of an optical fiber and its vicinity in a light diffusing device according to a third embodiment.
  • FIG. 13 is an enlarged perspective view of a light exit portion of an optical fiber and its vicinity in a light diffusing device according to a third embodiment.
  • FIG. 1 is a schematic diagram showing an example of use of a medical catheter set including a light diffusing device according to a first embodiment.
  • 11 is a cross-sectional view showing a modified example of a light exit portion of an optical fiber in a light diffusing device according to an embodiment.
  • FIG. 11 is a schematic diagram showing an example of use of a medical catheter set including a light diffusing device according to a first embodiment.
  • 11 is a cross-sectional view showing a modified example of a light exit portion of an optical fiber in a light diffusing device according to an embodiment.
  • Fig. 1 is a schematic diagram of a light diffusing device 1 according to a first embodiment
  • Fig. 2 is a cross-sectional view of a light emitting portion of an optical fiber in the light diffusing device 1 and a main portion in the vicinity thereof
  • Fig. 3 is a cross-sectional view of a portion of a light transmitting portion of an optical fiber in the light diffusing device 1
  • Fig. 4 is a cross-sectional view of a portion of a light emitting portion of an optical fiber in the light diffusing device
  • Fig. 5 is an enlarged horizontal cross-sectional view of a main portion of the light emitting portion of an optical fiber in the light diffusing device 1.
  • the base end side of the optical fiber is indicated by an arrow B, and the tip side is indicated by an arrow T.
  • Fig. 2 is a cross-sectional view taken along the line A-A in Figs. 3 and 4
  • Fig. 3 is a cross-sectional view taken along the line C-C in Fig. 2
  • Fig. 4 is a cross-sectional view taken along the line D-D in Fig. 2.
  • Fig. 6 is an enlarged cross-sectional view of the light emitting portion of the optical fiber in the light diffusion device 1 and its vicinity
  • Fig. 7 is a perspective view thereof.
  • the light diffusion device 1 is a device that emits light incident on the base end 20BE of the optical fiber 20 from the tip side T, and a light source 10 for generating light is connected to the base end 20BE on the base end side B of the optical fiber 20.
  • the light source 10 generates visible light or laser light. When generating laser light, it has a semiconductor laser, and generates laser light by passing electricity through the semiconductor laser to cause laser oscillation.
  • the light source 10 generates, for example, red laser light having a wavelength of 670 nm or more and 700 nm or less.
  • the optical fiber 20 is made of a resin (plastic) member. As shown in Figures 2 to 4, the optical fiber 20 is a single-core optical fiber consisting of a core 21 located in the center in the radial direction and a cladding 22 located on the outer periphery of the core 21.
  • the relative refractive index difference between the core 21 and the cladding 22 of the optical fiber 20 is 2% or more and 11% or less.
  • the optical fiber 20 has a core 21 made of acrylic resin (PMMA) with a refractive index of 1.40.
  • the cladding 22 is made of fluororesin, and the refractive index is adjusted to a range of 1.35 to 1.40 depending on the composition.
  • the optical fiber 20 has, for example, an outer diameter of 500 ⁇ m, an outer diameter of the core 21 of 480 ⁇ m, and a thickness of the cladding 22 of 10 ⁇ m.
  • the outer diameter of the cladding 22 of the optical fiber 20 is 102 ⁇ m or more and 1100 ⁇ m or less.
  • the outer diameter of the core 21 of the optical fiber 20 is 100 ⁇ m or more and 1000 ⁇ m or less.
  • the thickness of the cladding 22 is 1 ⁇ m or more and 50 ⁇ m or less.
  • the numerical aperture (NA) of the optical fiber 20 used is preferably 0.5 or more, and more preferably 0.6 or more.
  • the optical fiber 20 has a light transmitting section 20a that transmits the laser light incident from the base end 20BE toward the tip side T, and a light emitting section 20b that emits the laser light transmitted through the light transmitting section 20a from the outer circumferential surface by removing a portion located on the outer circumferential side of the cladding 22 within a predetermined range in the extension direction of the tip side T.
  • the light emitting portion 20b is formed within a range of, for example, 10 mm to 30 mm on the tip side T of the optical fiber 20.
  • the outer peripheral surface of the light emitting portion 20b has a cylindrical outer peripheral surface shape.
  • the light emitting portion 20b is formed by removing only the outer peripheral side of the cladding 22 by, for example, etching, while leaving the inner peripheral side in the thickness direction of the cladding 22.
  • the outer diameter Db of the cladding 22b in the light emitting portion 20b is defined as the diameter of the minimum circumscribing circle MCC, which is a circle that passes through the apex of the uneven surface 22f formed along the circumferential direction of the outer peripheral surface.
  • the light emitting portion 20b is formed so that the diameter Db of the minimum circumscribing circle MCC is smaller than the diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength ⁇ of the laser light transmitted through the light transmitting portion 20a (Db ⁇ Da- ⁇ ).
  • the diameter Da of the cladding 22a in the optical transmission section 20a is 500 ⁇ m and the wavelength ⁇ of the laser light is 680 nm (0.68 ⁇ m)
  • the diameter Db of the minimum circumscribed circle MCC of the cladding 22b in the optical emission section 20b is formed to a size of 499.32 ⁇ m or less (Db ⁇ 500-0.68).
  • the maximum thickness Tb max of the cladding 22b in the light emitting portion 20b is smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a (Tb max ⁇ Ta). It is preferable that the maximum thickness Tb max of the cladding 22b in the light emitting portion 20b is smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a by at least the wavelength ⁇ of the light transmitted through the light transmitting portion 20a (Tb max ⁇ Ta- ⁇ ).
  • the average thickness Tb of the cladding 22b in the light emitting portion 20b is preferably smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a by at least the wavelength ⁇ of the laser light transmitted through the light transmitting portion 20a (Tb ⁇ Ta - ⁇ ).
  • the average thickness Tb of the cladding 22b in the light emitting portion 20b is formed to a size of 9.32 ⁇ m or less (Tb ⁇ 10 - 0.68).
  • the change in the structure of the wavelength order in the longitudinal direction of the optical fiber causes the light intensity distribution of the cross section of the optical fiber to change more in the cladding portion, and more laser light is emitted from the outer peripheral surface of the light emitting portion 20b.
  • the uneven surface 22f formed along the circumferential direction of the cladding 22b in the light emitting portion 20b has a height difference Hb between the portion where the size of the projection toward the outer periphery is greatest and the portion where the size of the projection is least, which is equal to or less than the wavelength ⁇ of the laser light transmitted through the light transmitting portion 20a (Hb ⁇ ).
  • the thickness t of the cladding 22b in the light emitting portion 20b is preferably 1 ⁇ m or more (t ⁇ 1 ⁇ m) in an area that is 30% or more of the total area of the light emitting portion 20b. If the cladding 22b becomes too thin or disappears completely, the light in the core 21 will be trapped instead, so it is desirable to leave a certain thickness.
  • the percentage of the total area of the light emitting portion 20b where the thickness t of the cladding 22b in the light emitting portion 20b is 1 ⁇ m or more (t ⁇ 1 ⁇ m) can be calculated by observing multiple cross sections of the cut optical fiber using a scanning electron microscope (SEM) or the like, determining the percentage of the total length of the area with cladding of t ⁇ 1 ⁇ m to the total circumference, and averaging these.
  • SEM scanning electron microscope
  • optical fiber 20 is cut in multiple places (e.g., three places) in region 20b, and the cross sections are observed with an SEM. Then, the ratio of the region with cladding t ⁇ 1 ⁇ m to the total circumference is calculated, and the average of the obtained values is calculated.
  • the tip 20TE of the optical fiber 20 has an end face 20e that is oblique to the plane P perpendicular to the axis 21A of the core 21.
  • the end face 20e can be provided by cutting the optical fiber 20 at an angle in the middle.
  • the angle ⁇ between the plane P and the end face 20e can be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected, but by making the angle ⁇ less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected, the laser light can leak in the opposite direction to the reflection direction.
  • the laser light when the light source 10 is operated to cause laser light to be incident on the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b.
  • the tip end 20TE of the optical fiber 20 In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has an end face 20e that is inclined with respect to the plane P perpendicular to the axis 21A of the core 21 as described above, and the laser light is reflected by the end face 20e.
  • the laser light reflected by the end face 20e is irradiated laterally as shown by the arrow L2 in FIG. 2. Therefore, the efficiency of irradiating the laser light laterally can be improved (effect 1).
  • the outer diameter Db of the cladding 22b in the light emitting portion 20b is smaller than the outer diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength ⁇ of the light transmitted through the light transmitting portion 20a (Db ⁇ Da ⁇ ).
  • the laser light is irradiated laterally as shown by the arrow L1 in FIG. 2 (Effect 2).
  • the cladding 22b is thinned and the tip 20TE of the optical fiber 20 has an oblique end face 20e cut at an angle, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light within the optical fiber 20. This makes it easier for light to leak out from the sides, and as a result, the efficiency of irradiating the laser light to the sides can be improved (Effect 3).
  • this embodiment does not merely combine the side illumination effect (effect 1) of cutting the tip 20TE of the optical fiber 20 at an angle with the side illumination effect (effect 2) of appropriately thinning the cladding 22b in the light emitting portion 20b, but also provides a new, complex side illumination effect (effect 3) by organically linking the two configurations.
  • the new composite side irradiation effect (Effect 3) has a greater impact than the side irradiation effect (Effect 2) based on the thinning of the cladding.
  • the side irradiation based on the thinning of the cladding results in the irradiation area extending in the axial 21A direction (longitudinal direction) of the optical fiber 20.
  • the length of the light emitting portion 20b formed by thinning the cladding 22 in the axial 21A direction (longitudinal direction) is short.
  • the light emitting portion 20b is preferably formed within a range of, for example, 40 mm or less from the tip side T of the optical fiber 20, and more preferably within a range of 10 mm or less.
  • the light emitting portion 20b formed by thinning the cladding 22 extends to a region adjacent to the end face 20e at the tip side T of the optical fiber 20.
  • Fig. 8 is a cross-sectional view of the light output portion of the optical fiber and its vicinity in the light diffusing device 2 according to the second embodiment
  • Fig. 9 is an enlarged cross-sectional view of the light output portion of the optical fiber and its vicinity in the light diffusing device 2
  • Fig. 10 is a plan view (viewed from the right side on the paper surface of Figs. 8 and 9) seen from the tip side of the optical fiber in the light diffusing device 2. Since the light diffusing device 2 according to this embodiment has a configuration almost similar to that of the light diffusing device 1 according to the first embodiment, refer to Fig. 1 for an outline of the light diffusing device 2.
  • the E-E cross section in FIG. 8 is the same as FIG. 4, and the F-F cross section is the same as FIG. 3, so please refer to FIG. 3 and FIG. 4 for these cross sections.
  • the light diffusion device 2 according to the second embodiment has the same configuration as the light diffusion device 1 according to the first embodiment, except that the shape of the tip portion 20TE of the optical fiber 20 is unique to this embodiment. Therefore, the members having the same functions as the light diffusion device 1 according to the first embodiment are given the same reference numerals as in FIG. 1 to FIG. 7, and their description will be omitted.
  • the tip 20TE of the optical fiber 20 has a pair (two) end faces 20e1 and 20e2 that are inclined with respect to a plane P perpendicular to the axis 21A of the core 21.
  • the angle ⁇ between the plane P and the end face 20e1, and the angle ⁇ between the plane P and the end face 20e2 can both be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected.
  • the laser light when the light source 10 is operated to cause laser light to be incident on the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b.
  • the tip end 20TE of the optical fiber 20 In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has a pair of end faces that are inclined with respect to the plane P perpendicular to the axis 21A of the core 21 as described above, and is reflected by the end faces 20e1 and 20e2.
  • the reflected laser light travels in the directions of the arrows L21 and L22 , respectively. Therefore, in the present embodiment, the irradiation efficiency of the laser light in two lateral directions, one direction and the opposite direction, can be improved (Effect 1).
  • the outer diameter Db of the cladding 22b at the light output portion 20b is smaller than the outer diameter Da of the cladding 22a at the light transmission portion 20a by at least the wavelength ⁇ of the light transmitted through the light transmission portion 20a (Db ⁇ Da ⁇ ).
  • the laser light is irradiated laterally in two directions, that is, the one direction and the opposite direction, as shown by the arrow L1 in FIG. 8 (Effect 2).
  • the cladding 22b is thinned and the tip 20TE of the optical fiber 20 is cut at an angle to have the slanted end faces 20e1 and 20e2, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light and easier for it to leak out from the sides, thereby improving the efficiency of lateral laser light irradiation (Effect 3).
  • the remarkable effects are the lateral irradiation effect (effect 1) obtained by cutting the tip 20TE of the optical fiber 20 at an angle, the lateral irradiation effect (effect 2) obtained by appropriately thinning the cladding 22b in the light emitting portion 20b, and the new composite lateral irradiation effect (effect 3) obtained by organically linking these configurations.
  • the irradiation efficiency of the laser light can be improved in two lateral directions, one direction and the opposite direction.
  • the light diffusion device 2 according to this embodiment is used for irradiating the inside of a body or projecting light from inside the body onto the body surface
  • the light diffusion device 2 according to this embodiment is particularly suitable for the above-mentioned applications.
  • the number of obliquely cut end faces at the tip 20TE of the optical fiber 20 is not limited to two as in this embodiment, and may be three or more.
  • Fig. 11 is a cross-sectional view of a main part of a light output portion of an optical fiber and its vicinity in a light diffusing device 3 according to the third embodiment
  • Fig. 12 is an enlarged cross-sectional view of a light output portion of an optical fiber and its vicinity in the light diffusing device 3
  • Fig. 13 is a perspective view of a light output portion of an optical fiber and its vicinity in the light diffusing device 3. Since the light diffusing device 3 according to this embodiment has a configuration substantially similar to that of the light diffusing device 1 according to the first embodiment, refer to Fig. 1 for an outline of the light diffusing device 3.
  • the G-G cross section in FIG. 11 is the same as FIG. 4, and the H-H cross section is the same as FIG. 3, so please refer to FIG. 3 and FIG. 4 for these cross sections.
  • the light diffusion device 3 according to the third embodiment has the same configuration as the light diffusion device 1 according to the first embodiment, except that the shape of the tip portion 20TE of the optical fiber 20 is unique to this embodiment. Therefore, the members having the same functions as the light diffusion device 1 according to the first embodiment are given the same reference numerals as in FIG. 1 to FIG. 7, and their description will be omitted.
  • the tip 20TE of the optical fiber 20 has an end face 20e3 that is continuous in the circumferential direction of the optical fiber 20 and has a conical shape.
  • the angle ⁇ between the plane P and the end face 20e3 can be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected.
  • the laser light when the light source 10 is operated to cause laser light to enter the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b.
  • the tip end 20TE of the optical fiber 20 In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has an end face 20e3 that is continuous in the circumferential direction of the optical fiber 20 and has a conical shape as described above, and is reflected by the end face 20e3.
  • the reflected laser light travels radially in the direction of the arrow L3 that intersects with the axis 21A. Therefore, in this embodiment, the irradiation efficiency of the laser light that travels radially to the side can be improved (Effect 1).
  • the outer diameter Db of the cladding 22b in the light emitting portion 20b is smaller than the outer diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength ⁇ of the light transmitted through the light transmitting portion 20a (Db ⁇ Da ⁇ ).
  • the laser light is irradiated radially to the side, as shown by the arrow L1 in FIG. 11 (Effect 2).
  • the cladding 22b is thinned and the tip 20TE of the optical fiber 20 has an oblique end face 20e3 cut at an angle, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light and allowing it to easily leak out radially to the side, improving the irradiation efficiency of the laser light that travels radially to the side (Effect 3).
  • the remarkable effects are the lateral irradiation effect (effect 1) obtained by cutting the tip 20TE of the optical fiber 20 at an angle, the lateral irradiation effect (effect 2) obtained by appropriately thinning the cladding 22b in the light emitting portion 20b, and the new composite lateral irradiation effect (effect 3) obtained by organically linking these configurations.
  • the end face 20e3 is continuous in the circumferential direction of the optical fiber 20 and has a conical shape, so that the irradiation efficiency of the laser light can be improved for the entire lateral circumference.
  • the light diffusion device 3 of this embodiment when the light diffusion device 3 of this embodiment is used for irradiating the inside of a body or projecting light from inside the body onto the body surface, irradiation is performed radially in the entire circumferential direction centered on the axis 21A of the optical fiber 20, so there is no need to align the irradiation position in the rotational direction centered on the axis 21A. Therefore, the light diffusion device 3 of this embodiment is particularly suitable for the above-mentioned applications.
  • the light diffusion device according to the embodiment described above can be inserted into the body as it is or together with other accessories as appropriate, and used as a diffuser for irradiating an affected area with laser light.
  • the light diffusion device according to the embodiment described above can also be inserted into the body together with an endoscope, catheter, or the like, and used as a so-called light source to illuminate the inside of the body or project light onto the body surface from inside the body.
  • an endoscope, catheter, or the like used as a so-called light source to illuminate the inside of the body or project light onto the body surface from inside the body.
  • FIG. 14 is a schematic diagram showing an example of the use of a medical catheter set 30 when the light diffusion device 1 according to the first embodiment is used together with a catheter.
  • the medical catheter set 30 includes a catheter 26 and a light diffusion device 1, and as shown in FIG. 14, when in use, the optical fiber 20 of the light diffusion device 1 is inserted into the catheter 26 and is available to the practitioner.
  • the medical catheter set 30 can be inserted into the body together with an endoscope from the tip side T, and the tip of the catheter 26 can be guided to the desired location while observing the inside of the body with the endoscope by irradiating light from the light emitting unit 20b.
  • the catheter can be inserted into the body without an endoscope, and light can be irradiated into the body from the light emitting unit 20b and projected onto the body surface, allowing the position of the tip of the catheter 26 to be confirmed from outside the body while the tip position is guided to the desired location.
  • the practitioner can pull out the optical fiber 20 of the light diffusion device 1 from the catheter 26 and use the catheter 26 for the desired medical purpose to perform the medical procedure.
  • the tip 20TE of the optical fiber 20 is used in a state where it is fitted inside the tube of the catheter 26. If a tube made of a light-impermeable material is used as the catheter 26, the tip 20TE of the optical fiber 20 may be protruded from the tip of the catheter 26 to expose at least a part of the light emitting portion 20b, or the tip 20TE of the optical fiber 20 may be positioned near the tip opening of the catheter 26 to allow the light emitted from the light emitting portion 20b to leak out from the tip opening of the catheter 26.
  • the portion of the light emitting portion 20b located on the outer periphery of the clad 22 is removed in the circumferential direction, but this is not limited to the above.
  • an optical fiber that emits laser light from the outer periphery of the light emitting portion 20b as shown in FIG. 15, only a portion of the portion of the light emitting portion 20b located on the outer periphery of the clad 22 may be removed in the circumferential direction, so that the laser light is emitted from only a portion of the circumferential direction.
  • the light emitting portion is formed in at least a portion of the circumferential direction on the tip side of the optical fiber.
  • the light emitting portion may be formed in a portion that covers 30% or more of the circumference of the tip side of the optical fiber, for example, within a range of 120 degrees to 180 degrees in the circumference of the tip side of the optical fiber.
  • the light emitting portions may also be formed discretely in the circumference of the tip side of the optical fiber, and their total area may be 30% or more of the total area of the outer circumferential surface of the tip part of the optical fiber.
  • the area of the light emitting portion on the outer surface of the tip of the optical fiber can be calculated by observing multiple cross sections of the cut optical fiber using a SEM (scanning electron microscope) or similar, calculating the ratio of the total length of the area where the cladding has been removed to the total circumference, and averaging these.
  • the optical fiber 20 is cut in the region 20b in multiple places (e.g., three places) and the cross sections are observed with an SEM.
  • the proportion of the region of the thin cladding 22 that forms the uneven surface 22f to the total perimeter is then calculated. In the cross section of Figure 15, it is 50%.
  • the area of the light emitting portion on the outer periphery of the tip of the optical fiber is calculated by averaging the values obtained for the multiple cross sections.
  • unevenness refers to the difference Rz between the maximum peak of the unevenness and the minimum valley bottom (maximum height of the contour curve: see JIS B0601).
  • Example 1 a medical catheter set 30 and a light source 10 shown in Fig. 15 including a light diffusion device 1 similar to those of the first embodiment shown in Figs. 1 to 7 were prepared.
  • the specific specifications and conditions of Example 1 are as follows. Note that specifications and conditions not described below are as described in the description of the first embodiment above.
  • Length of the light emitting portion 20b in the direction of the axis 21A 5 mm
  • Method for removing cladding 22 Etching for 5 seconds
  • Example 1 In addition, from the configuration of Example 1 above, except that the tip 20TE of the optical fiber 20 is not cut at an angle, and an end face is not provided at an angle with respect to the plane P perpendicular to the axis 21A of the core 21, a device with the same specifications and conditions as Example 1 was prepared, and this was used as the light diffusion device of Comparative Example 1.
  • Example 2 Separately from the configuration of Example 1 above, a device with the same specifications and conditions as Example 1 was prepared, except that etching was not performed to remove the cladding 22, and no light emitting portion 20b was provided, and this was used as the light diffusion device of Comparative Example 2 (an end face was provided that was oblique to the plane P perpendicular to the axis 21A of the core 21).
  • the light source 10 was operated under the above specifications and conditions to cause light to enter from the base end 20BE of the optical fiber 20 and exit (irradiate) from the light exit portion 20b (the portion corresponding to 20b in Comparative Example 2; the same applies below).
  • a light receiving diameter of 3 mm (S151C, manufactured by Thorlabs) was placed at a position 1 mm away from the side of the light exit portion 20b in a specific direction perpendicular to the axis 21A (lateral component measurement) and at a position 1 mm away from the tip end 20TE of the optical fiber 20 in a direction perpendicular to the axis 21A (direct component measurement) to measure the amount of light.
  • the lateral component measurement was performed at two locations, and the average was taken as the measured value. The results are shown in Table 1 below.
  • Comparative Example 1 which does not have an oblique end face, very little lateral light component was detected, and in Comparative Example 2, in which the cladding 22 was not thinned, some lateral light component was detected, but it was significantly smaller than in Example 1.
  • Example 1 combines the configurations of Comparative Examples 1 and 2, but it does not merely achieve the effect of combining the configurations of Comparative Examples 1 and 2; it also achieves a significantly higher lateral illumination efficiency.
  • Light diffusion device 10 light source, 20 optical fiber, 20a optical transmission unit, 20b light emitting portion, 20e, 20e1, 20e2, 20e3 end face, 20BE base end, 20TE tip, 21 cores, 22, 22a, 22b clad, 22f uneven surface, 26 catheter, 30 Medical catheter set

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Abstract

Provided are a light diffusion device capable of efficiently emitting light transmitted through a light transmission portion in a specific direction of a side surface, and a medical catheter set provided therewith. A light diffusion device (1) is provided with an optical fiber (20) comprising a core (21) and a cladding (22), and emits light incident from a base end portion of the optical fiber (20) from the tip side (T) of the optical fiber (20). The optical fiber (20) has a light transmission portion (20a) through which the light is transmitted toward a tip portion (20TE), and a light emission portion (20b) in which the outer peripheral side of the classing (22) on the tip side (T) is removed, the outer diameter (Db) of a cladding (22b) in the light emission portion (20b) being smaller than the outer diameter (Da) of a cladding (22a) in the light transmission portion (20a) by the magnitude of the wavelength λ of the light transmitted through the light transmission portion (20a) or more (Db ≤ Da-λ), and the optical fiber (20) has an end surface (20e) slanted with respect to a plane (P) perpendicular to the axis (21A) of the core (21) at the tip portion (20TE) on the tip side (T) of the optical fiber (20).

Description

光拡散装置及びこれを備える医療用カテーテルセットLight diffusing device and medical catheter set including the same

　本発明は、医療機器に用いられる光拡散装置及びこれを備える医療用カテーテルセットに関する。 The present invention relates to a light diffusion device for use in medical equipment and a medical catheter set equipped with the same.

　従来の光拡散装置としては、径方向の中心側に位置するコアと、前記コアの外周側に位置するクラッドと、からなる光ファイバを備え、光ファイバの基端部から入射したレーザ光を、光ファイバの先端部および先端側の外周面から出射させるものが知られている（例えば、特許文献１参照）。従来の光拡散装置の光ファイバは、基端部から入射したレーザ光を伝送する光伝送部と、先端側において前記光伝送部を伝送されたレーザ光を出射させる光出射部と、を有している。 A conventional light diffusion device is known that includes an optical fiber consisting of a core located at the center in the radial direction and a cladding located on the outer periphery of the core, and that emits laser light incident on the base end of the optical fiber from the tip end and the outer periphery on the tip side (see, for example, Patent Document 1). The optical fiber of the conventional light diffusion device has a light transmission section that transmits the laser light incident on the base end, and a light emission section at the tip side that emits the laser light transmitted through the light transmission section.

　光拡散装置は、癌の治療法の１つである光免疫療法において、光ファイバの先端側を人体内に挿入し、人体に投与されて癌細胞に到達した薬剤にレーザ光を照射するために用いられている。また、光拡散装置は、胃カメラなどの内視鏡やカテーテル等と共に体内に挿入して、体内を照射したり、体内から体表面に投影させたりするためにも用いられている。 Light diffusion devices are used in photoimmunotherapy, a cancer treatment method, by inserting the tip of an optical fiber into the human body and irradiating laser light onto drugs that have been administered to the body and reached the cancer cells. Light diffusion devices are also used by inserting them into the body together with endoscopes such as gastroscopes and catheters to irradiate the inside of the body or project light from inside the body onto its surface.

特表２００１－５０２４３８号公報Special Publication No. 2001-502438

　従来の光拡散装置は、光ファイバの先端側のクラッドを部分的に除去してコアを露出させることによって、光出射部の外周面から光を出射させている。この場合、従来の光拡散装置は、光出射部におけるコアの屈折率とコアの外周側に位置する空気の屈折率との差異が大きくなり、光の閉じ込め効果が強くなる。このため、光出射部から出射されるレーザ光は、光出射部の全体における出射強度が制限されることとなる。 　Conventional light diffusion devices emit light from the outer surface of the light output section by partially removing the cladding at the tip side of the optical fiber to expose the core. In this case, in conventional light diffusion devices, the difference between the refractive index of the core at the light output section and the refractive index of the air located on the outer periphery of the core becomes large, and the light confinement effect becomes stronger. As a result, the laser light emitted from the light output section has a limited emission intensity throughout the entire light output section.

　したがって、光伝送部を伝送された光を効率よく側面の特定方向に向けて出射し得る光拡散装置及びこれを備える医療用カテーテルセットを提供することを目的の一つとする。 Therefore, one of the objectives is to provide a light diffusion device that can efficiently emit light transmitted through a light transmission section in a specific direction on the side, and a medical catheter set equipped with the same.

　本発明の一態様である光拡散装置は、径方向の中心側に位置するコアと、前記コアの外周側に位置するクラッドと、からなる光ファイバを備え、前記光ファイバの基端部から入射した光を、前記光ファイバの先端側から出射させる光拡散装置であって、
　基端部から入射した光を先端部に向かって伝送する光伝送部と、先端側における前記クラッドの外周側に位置する部分を除去した光出射部と、を有し、
　前記光出射部における前記クラッドの外径Ｄｂが、前記光伝送部における前記クラッドの外径Ｄａよりも、前記光伝送部を伝送される光の波長λの大きさ以上に小さく（Ｄｂ≦Ｄａ－λ） 、かつ、
　前記光ファイバの先端側の端部に、前記コアの軸に垂直の平面に対して斜めの端面を有する。 A light diffusing device according to one aspect of the present invention is a light diffusing device comprising an optical fiber having a core located at a radial center side and a clad located on an outer peripheral side of the core, the light diffusing device causing light incident on a base end of the optical fiber to exit from a tip end side of the optical fiber,
a light transmitting section that transmits light incident from a base end section toward a tip end section, and a light emitting section that is formed by removing a portion located on an outer circumferential side of the clad on the tip side,
The outer diameter Db of the cladding in the light emitting portion is smaller than the outer diameter Da of the cladding in the light transmitting portion by at least the wavelength λ of the light transmitted through the light transmitting portion (Db≦Da−λ), and
The optical fiber has an end face at an angle to a plane perpendicular to the axis of the core at the end on the tip side.

　前記光出射部における前記クラッドの厚さｔが、前記光出射部の全面積における３０％以上の領域で１μｍ以上であってもよい。 The thickness t of the cladding in the light emitting portion may be 1 μm or more in an area that accounts for 30% or more of the total area of the light emitting portion.

　前記光出射部が、前記光ファイバの先端側において、前記端面に連なる領域まで延びていてもよい。 The light emitting portion may extend to a region adjacent to the end face at the tip side of the optical fiber.

　前記光ファイバの先端側の端部に、前記コアの軸に垂直の平面に対して斜めの端面を２以上有していてもよい。 The tip end of the optical fiber may have two or more end faces that are oblique to a plane perpendicular to the axis of the core.

　前記端面が、前記光ファイバの周方向において連続的であり、かつ、当該端面の形状が円錐形状であってもよい。 The end face may be continuous in the circumferential direction of the optical fiber, and may have a conical shape.

　前記端面と前記コアの軸に垂直の平面との成す角が、前記光伝送部を伝送される光を全反射する最小角度未満であってもよい。 The angle between the end face and a plane perpendicular to the axis of the core may be less than the minimum angle at which light transmitted through the optical transmission section is totally reflected.

　前記光ファイバが樹脂製の光ファイバであってもよい。 The optical fiber may be made of resin.

　　前記光ファイバの開口数（ＮＡ）が０．５以上であってもよい。 The numerical aperture (NA) of the optical fiber may be 0.5 or more.

　前記光出射部における前記光ファイバの外表面に、凹凸が形成されていてもよい。 The outer surface of the optical fiber in the light emitting section may be uneven.

　本発明の一態様である医療用カテーテルセットは、カテーテルと、上記本発明の一態様である光拡散装置と、を備えたものである。 The medical catheter set according to one aspect of the present invention includes a catheter and the light diffusion device according to one aspect of the present invention.

　本発明の一態様によれば、光伝送部を伝送された光を効率よく側面の特定方向に向けて出射し得る光拡散装置及びこれを備える医療用カテーテルセットを提供することができる。 According to one aspect of the present invention, it is possible to provide a light diffusion device that can efficiently emit light transmitted through a light transmission section in a specific direction on the side, and a medical catheter set that includes the same.

本発明の例示的態様である第１の実施形態にかかる光拡散装置の概略図である。1 is a schematic diagram of a light diffusing device according to a first embodiment which is an exemplary aspect of the present invention. 第１の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の要部断面図であり、図３及び図４におけるＡ－Ａ断面にかかる断面図である。5 is a cross-sectional view of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment and a main portion in the vicinity thereof, taken along the line AA in FIGS. 3 and 4. FIG. 第１の実施形態にかかる光拡散装置における光ファイバの光伝送部の部位の横断面図であり、図２におけるＣ－Ｃ断面にかかる断面図である。3 is a cross-sectional view of a portion of a light transmitting portion of an optical fiber in the light diffusing device according to the first embodiment, taken along the CC cross section in FIG. 2. 第１の実施形態にかかる光拡散装置における光ファイバの光出射部の部位の横断面図であり、図２におけるＤ－Ｄ断面にかかる断面図である。3 is a cross-sectional view of a portion of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment, taken along the line DD in FIG. 2. 第１の実施形態にかかる光拡散装置における光ファイバの光出射部の要部における横拡大断面図である。3 is an enlarged horizontal cross-sectional view of a main part of a light emitting portion of an optical fiber in the light diffusing device according to the first embodiment. FIG. 第１の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の拡大断面図である。3 is an enlarged cross-sectional view of a light exit portion of an optical fiber in the light diffusing device according to the first embodiment and its vicinity. FIG. 第１の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の拡大斜視図である。2 is an enlarged perspective view of a light exit portion of an optical fiber and its vicinity in the light diffusing device according to the first embodiment; FIG. 第２の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の要部断面図である。11 is a cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a second embodiment and a main portion in the vicinity thereof. FIG. 第２の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の拡大断面図である。11 is an enlarged cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a second embodiment and its vicinity. FIG. 第２の実施形態にかかる光拡散装置における光ファイバの先端側から見た平面図である。13 is a plan view of a light diffusing device according to a second embodiment, as viewed from the tip side of an optical fiber. FIG. 第３の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の要部断面図である。13 is a cross-sectional view of a light exit portion of an optical fiber in a light diffusing device according to a third embodiment and its vicinity. FIG. 第３の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の拡大断面図である。13 is an enlarged cross-sectional view of a light exit portion of an optical fiber and its vicinity in a light diffusing device according to a third embodiment. FIG. 第３の実施形態にかかる光拡散装置における光ファイバの光出射部及びその近傍の拡大斜視図である。13 is an enlarged perspective view of a light exit portion of an optical fiber and its vicinity in a light diffusing device according to a third embodiment. FIG. 第１の実施形態にかかる光拡散装置を備える医療用カテーテルセットの使用例を示す概略図である。1 is a schematic diagram showing an example of use of a medical catheter set including a light diffusing device according to a first embodiment. 実施形態にかかる光拡散装置における光ファイバの光出射部の変形例を示す横断面図である。11 is a cross-sectional view showing a modified example of a light exit portion of an optical fiber in a light diffusing device according to an embodiment. FIG.

　以下、本発明の例示的態様である３つの実施形態にかかる光拡散装置について、図面を参照しながら具体的に説明する。 Below, three exemplary embodiments of the light diffusion device according to the present invention will be described in detail with reference to the drawings.

＜第１の実施形態＞
　図１は第１の実施形態にかかる光拡散装置１の概略図であり、図２は光拡散装置１における光ファイバの光出射部及びその近傍の要部断面図であり、図３は光拡散装置１における光ファイバの光伝送部の部位の横断面図であり、図４は光拡散装置１における光ファイバの光出射部の部位の横断面図であり、図５は光拡散装置１における光ファイバの光出射部の要部における横拡大断面図である。なお、光ファイバの基端側を矢印Ｂ、先端側を矢印Ｔで示す。 First Embodiment
Fig. 1 is a schematic diagram of a light diffusing device 1 according to a first embodiment, Fig. 2 is a cross-sectional view of a light emitting portion of an optical fiber in the light diffusing device 1 and a main portion in the vicinity thereof, Fig. 3 is a cross-sectional view of a portion of a light transmitting portion of an optical fiber in the light diffusing device 1, Fig. 4 is a cross-sectional view of a portion of a light emitting portion of an optical fiber in the light diffusing device 1, and Fig. 5 is an enlarged horizontal cross-sectional view of a main portion of the light emitting portion of an optical fiber in the light diffusing device 1. The base end side of the optical fiber is indicated by an arrow B, and the tip side is indicated by an arrow T.

　詳しくは、図２は図３及び図４におけるＡ－Ａ断面にかかる断面図であり、図３は図２におけるＣ－Ｃ断面にかかる断面図であり、図４は図２におけるＤ－Ｄ断面にかかる断面図である。また、図６は光拡散装置１における光ファイバの光出射部及びその近傍の拡大断面図であり、図７はその斜視図である。 In detail, Fig. 2 is a cross-sectional view taken along the line A-A in Figs. 3 and 4, Fig. 3 is a cross-sectional view taken along the line C-C in Fig. 2, and Fig. 4 is a cross-sectional view taken along the line D-D in Fig. 2. Fig. 6 is an enlarged cross-sectional view of the light emitting portion of the optical fiber in the light diffusion device 1 and its vicinity, and Fig. 7 is a perspective view thereof.

　光拡散装置１は、光ファイバ２０の基端部２０ＢＥから入射した光を先端側Ｔから出射させる装置であり、光ファイバ２０の基端側Ｂの基端部２０ＢＥには、光を発生させるための光源１０が接続されている The light diffusion device 1 is a device that emits light incident on the base end 20BE of the optical fiber 20 from the tip side T, and a light source 10 for generating light is connected to the base end 20BE on the base end side B of the optical fiber 20.

　光源１０は、可視光乃至レーザ光を発生させるものである。レーザ光を発生させる場合には、半導体レーザを有し、半導体レーザに電気を流すことでレーザ発振を生じさせ、レーザ光を発生させる。光源１０は、例えば、６７０ｎｍ以上７００ｎｍ以下の波長を有する赤色のレーザ光を発生させる。 The light source 10 generates visible light or laser light. When generating laser light, it has a semiconductor laser, and generates laser light by passing electricity through the semiconductor laser to cause laser oscillation. The light source 10 generates, for example, red laser light having a wavelength of 670 nm or more and 700 nm or less.

　光ファイバ２０は、樹脂（プラスチック）製の部材からなる。光ファイバ２０は、図２～図４に示すように、径方向の中心側に位置するコア２１と、コア２１の外周側に位置するクラッド２２と、からなるシングルコア光ファイバである。光ファイバ２０は、コア２１とクラッド２２との比屈折率差が、２％以上１１％以下である。 The optical fiber 20 is made of a resin (plastic) member. As shown in Figures 2 to 4, the optical fiber 20 is a single-core optical fiber consisting of a core 21 located in the center in the radial direction and a cladding 22 located on the outer periphery of the core 21. The relative refractive index difference between the core 21 and the cladding 22 of the optical fiber 20 is 2% or more and 11% or less.

　光ファイバ２０としては、具体的には例えば、コア２１がアクリル樹脂（ＰＭＭＡ）であり屈折率は１．４０である。また、クラッド２２はフッ素樹脂であり、組成によって屈折率が１．３５～１．４０の範囲で調整される。 Specifically, for example, the optical fiber 20 has a core 21 made of acrylic resin (PMMA) with a refractive index of 1.40. The cladding 22 is made of fluororesin, and the refractive index is adjusted to a range of 1.35 to 1.40 depending on the composition.

　光ファイバ２０は、例えば、外径が５００μｍであり、コア２１の外径が４８０μｍであり、クラッド２２の厚さが１０μｍである。ここで、光ファイバ２０は、クラッド２２の外径が、１０２μｍ以上１１００μｍ以下であることが好ましい。また、光ファイバ２０は、コア２１の外径が、１００μｍ以上１０００μｍ以下であることが好ましい。クラッド２２は、厚さが１μｍ以上５０μｍ以下であることが好ましい。 The optical fiber 20 has, for example, an outer diameter of 500 μm, an outer diameter of the core 21 of 480 μm, and a thickness of the cladding 22 of 10 μm. Here, it is preferable that the outer diameter of the cladding 22 of the optical fiber 20 is 102 μm or more and 1100 μm or less. It is also preferable that the outer diameter of the core 21 of the optical fiber 20 is 100 μm or more and 1000 μm or less. It is preferable that the thickness of the cladding 22 is 1 μm or more and 50 μm or less.

　用いる光ファイバ２０の開口数（ＮＡ）としては、０．５以上であることが好ましく、０．６以上であることがより好ましい。開口数が適切に大きい光ファイバ２０を用いることで、予め広角に光を光ファイバ２０内に入射させておくことで、光が周面の全面から放射しやすくなるため、クラッドを薄くする効果と相俟って、側面発光させることがより容易になる。 The numerical aperture (NA) of the optical fiber 20 used is preferably 0.5 or more, and more preferably 0.6 or more. By using an optical fiber 20 with an appropriately large numerical aperture, and by injecting light into the optical fiber 20 at a wide angle in advance, the light is more likely to radiate from the entire circumferential surface, which, combined with the effect of making the cladding thinner, makes it easier to emit light from the side.

　光ファイバ２０は、図１及び図２に示すように、基端部２０ＢＥから入射したレーザ光を先端側Ｔに向かって伝送する光伝送部２０ａと、先端側Ｔの延在方向の所定範囲内のクラッド２２の外周側に位置する部分を除去することによって光伝送部２０ａを伝送されたレーザ光を外周面から出射させる光出射部２０ｂと、を有している。 As shown in Figures 1 and 2, the optical fiber 20 has a light transmitting section 20a that transmits the laser light incident from the base end 20BE toward the tip side T, and a light emitting section 20b that emits the laser light transmitted through the light transmitting section 20a from the outer circumferential surface by removing a portion located on the outer circumferential side of the cladding 22 within a predetermined range in the extension direction of the tip side T.

　光出射部２０ｂは、光ファイバ２０の先端側Ｔの例えば１０ｍｍ以上３０ｍｍ以下の範囲内に形成される。光出射部２０ｂの外周面は、円柱の外周面形状（シリンドリカル状）になっている。光出射部２０ｂは、クラッド２２の厚み方向における内周側を残して、クラッド２２の外周側のみを例えばエッチング加工により除去することで形成される。 The light emitting portion 20b is formed within a range of, for example, 10 mm to 30 mm on the tip side T of the optical fiber 20. The outer peripheral surface of the light emitting portion 20b has a cylindrical outer peripheral surface shape. The light emitting portion 20b is formed by removing only the outer peripheral side of the cladding 22 by, for example, etching, while leaving the inner peripheral side in the thickness direction of the cladding 22.

　図３及び図４を参照して説明する。光出射部２０ｂは、クラッド２２を除去することによって径方向の大きさが、光伝送部２０ａの直径Ｄａ（図４参照）よりもレーザ光の波長の大きさ以上に小さくなる（即ち、除去されたクラッド２２の厚みがレーザ光の波長の大きさの半分以上になる）と、光ファイバ２０の長手方向の波長オーダの構造の変化により、光ファイバ２０の断面の光強度分布が変化し、光が漏れるようになり、外周面からレーザ光が出射されるようになる。 The explanation will be given with reference to Figures 3 and 4. When the radial size of the light emitting section 20b becomes smaller than the diameter Da (see Figure 4) of the light transmitting section 20a by removing the cladding 22 by more than the wavelength of the laser light (i.e., the thickness of the removed cladding 22 becomes more than half the wavelength of the laser light), the change in the structure of the optical fiber 20 in the longitudinal direction of the wavelength order changes the light intensity distribution of the cross section of the optical fiber 20, causing light to leak and laser light to be emitted from the outer peripheral surface.

　しかし、光出射部２０ｂは、外周面の延在方向および周方向にわたって均一にクラッド２２を除去することは困難であり、部分的にばらつきを有している。上記のような光ファイバ２０の長手方向に対する構造の変化により、光が出射する現象はモードのミスマッチによるものである。 However, it is difficult to remove the cladding 22 uniformly from the light emitting portion 20b in the direction of extension and the circumferential direction of the outer peripheral surface, and there is some variation. The phenomenon in which light is emitted due to the change in the structure of the optical fiber 20 in the longitudinal direction as described above is due to a mode mismatch.

　ここで、図４に示すように、光出射部２０ｂにおけるクラッド２２ｂの外径Ｄｂを、外周面の周方向に沿って形成される凹凸面２２ｆの頂部を通る円である最小外接円ＭＣＣの径と定義する。そして、最小外接円ＭＣＣの径Ｄｂが、光伝送部２０ａにおけるクラッド２２ａの直径Ｄａよりも光伝送部２０ａを伝送されるレーザ光の波長λの大きさ以上に小さくなる（Ｄｂ≦Ｄａ－λ）ように光出射部２０ｂを形成する。 Here, as shown in FIG. 4, the outer diameter Db of the cladding 22b in the light emitting portion 20b is defined as the diameter of the minimum circumscribing circle MCC, which is a circle that passes through the apex of the uneven surface 22f formed along the circumferential direction of the outer peripheral surface. The light emitting portion 20b is formed so that the diameter Db of the minimum circumscribing circle MCC is smaller than the diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength λ of the laser light transmitted through the light transmitting portion 20a (Db≦Da-λ).

　即ち、例えば、光伝送部２０ａにおけるクラッド２２ａの直径Ｄａが５００μｍで、レーザ光の波長λが６８０ｎｍ（０．６８μｍ）の場合には、光出射部２０ｂにおけるクラッド２２ｂの最小外接円ＭＣＣの直径Ｄｂを、４９９．３２μｍ以下（Ｄｂ≦５００－０．６８）となる大きさに形成する。光の進行の過程で光の波長λより大きな外径変化を与えることにより、光は、より長手方向の構造の変化を敏感に感じ取って光照射されることになる。 That is, for example, if the diameter Da of the cladding 22a in the optical transmission section 20a is 500 μm and the wavelength λ of the laser light is 680 nm (0.68 μm), the diameter Db of the minimum circumscribed circle MCC of the cladding 22b in the optical emission section 20b is formed to a size of 499.32 μm or less (Db≦500-0.68). By imparting a change in outer diameter greater than the wavelength λ of the light during the light's propagation, the light is more sensitive to changes in the longitudinal structure and is irradiated.

　また、光出射部２０ｂにおけるクラッド２２ｂの最大厚さＴｂｍａｘは、光伝送部２０ａにおけるクラッド２２ａの厚さＴａよりも小さく形成されている（Ｔｂｍａｘ＜Ｔａ）。光出射部２０ｂにおけるクラッド２２ｂの最大厚さＴｂｍａｘは、光伝送部２０ａにおけるクラッド２２ａの厚さＴａよりも光伝送部２０ａを伝送される光の波長λの大きさ以上に小さい（Ｔｂｍａｘ≦Ｔａ－λ）、ことが好ましい。 Furthermore, the maximum thickness Tb max of the cladding 22b in the light emitting portion 20b is smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a (Tb max <Ta). It is preferable that the maximum thickness Tb max of the cladding 22b in the light emitting portion 20b is smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a by at least the wavelength λ of the light transmitted through the light transmitting portion 20a (Tb max ≦Ta-λ).

　また、図３および図４に示すように、光出射部２０ｂにおけるクラッド２２ｂの平均厚さＴｂ（図４中の一点鎖線参照）は、光伝送部２０ａにおけるクラッド２２ａの厚さＴａよりも光伝送部２０ａを伝送されるレーザ光の波長λの大きさ以上に小さく形成されている（Ｔｂ≦Ｔａ－λ）、ことが好ましい。即ち、例えば、光伝送部２０ａのクラッド２２ａの厚さＴａが１０μｍで、レーザ光の波長λが６８０ｎｍ（０．６８μｍ）の場合には、光出射部２０ｂにおけるクラッド２２ｂの平均厚さＴｂを、９．３２μｍ以下（Ｔｂ≦１０－０．６８）となる大きさに形成する。これにより、光ファイバの長手方向の波長オーダの構造の変化により、クラッド部分で光ファイバの断面の光強度分布がより変化することになり、光出射部２０ｂの外周面からレーザ光がより多く出射されるようになる。 As shown in Figs. 3 and 4, the average thickness Tb of the cladding 22b in the light emitting portion 20b (see the dashed line in Fig. 4) is preferably smaller than the thickness Ta of the cladding 22a in the light transmitting portion 20a by at least the wavelength λ of the laser light transmitted through the light transmitting portion 20a (Tb ≦ Ta - λ). That is, for example, when the thickness Ta of the cladding 22a in the light transmitting portion 20a is 10 μm and the wavelength λ of the laser light is 680 nm (0.68 μm), the average thickness Tb of the cladding 22b in the light emitting portion 20b is formed to a size of 9.32 μm or less (Tb ≦ 10 - 0.68). As a result, the change in the structure of the wavelength order in the longitudinal direction of the optical fiber causes the light intensity distribution of the cross section of the optical fiber to change more in the cladding portion, and more laser light is emitted from the outer peripheral surface of the light emitting portion 20b.

　さらに、光出射部２０ｂにおけるクラッド２２ｂの周方向に沿って形成される凹凸面２２ｆは、図５に示すように、外周側に張り出す大きさが最も大きくなる部分と最も小さくなる部分との高さの差Ｈｂが、光伝送部２０ａを伝送されるレーザ光の波長λの大きさ以下である（Ｈｂ≦λ）、ことが好ましい。クラッド部分での局所的で微細な構造変化が小さくなることにより、より均一な出射特性を実現できる。同時に光出射部２０ｂの外周面と空気との界面の面積を減らすことができるため、界面の熱抵抗を低減でき、発熱を減らすことができる。 Furthermore, as shown in FIG. 5, it is preferable that the uneven surface 22f formed along the circumferential direction of the cladding 22b in the light emitting portion 20b has a height difference Hb between the portion where the size of the projection toward the outer periphery is greatest and the portion where the size of the projection is least, which is equal to or less than the wavelength λ of the laser light transmitted through the light transmitting portion 20a (Hb≦λ). By reducing the localized and minute structural changes in the cladding portion, more uniform emission characteristics can be achieved. At the same time, the area of the interface between the outer periphery of the light emitting portion 20b and the air can be reduced, thereby reducing the thermal resistance at the interface and reducing heat generation.

　光出射部２０ｂにおけるクラッド２２ｂの厚さｔとしては、光出射部２０ｂの全面積における３０％以上の領域で１μｍ以上（ｔ≧１μｍ）であることが好ましい。クラッド２２ｂが薄くなりすぎたり、完全に無くなってしまうと、コア２１内の光が却って閉じ込められてしまうため、ある程度の厚みを残しておくことが望ましい。 The thickness t of the cladding 22b in the light emitting portion 20b is preferably 1 μm or more (t≧1 μm) in an area that is 30% or more of the total area of the light emitting portion 20b. If the cladding 22b becomes too thin or disappears completely, the light in the core 21 will be trapped instead, so it is desirable to leave a certain thickness.

　光出射部２０ｂにおけるクラッド２２ｂの厚さｔが１μｍ以上（ｔ≧１μｍ）である領域の光出射部２０ｂの全面積における割合は、光ファイバを切断した複数の断面をＳＥＭ（走査型電子顕微鏡）等で観察し、全周長に対するｔ≧１μｍのクラッドがある領域の合計長さの割合を求め、これを平均することで求めることができる。 The percentage of the total area of the light emitting portion 20b where the thickness t of the cladding 22b in the light emitting portion 20b is 1 μm or more (t≧1 μm) can be calculated by observing multiple cross sections of the cut optical fiber using a scanning electron microscope (SEM) or the like, determining the percentage of the total length of the area with cladding of t≧1 μm to the total circumference, and averaging these.

　図２を参照して説明すると、光ファイバ２０を２０ｂの領域で複数（例えば３カ所）切断し、その断面をＳＥＭで観察する。そして、ｔ≧１μｍのクラッドがある領域の全周長に対する割合をそれぞれ求め、得られた値の平均を求めればよい。 Referring to Figure 2, optical fiber 20 is cut in multiple places (e.g., three places) in region 20b, and the cross sections are observed with an SEM. Then, the ratio of the region with cladding t ≥ 1 μm to the total circumference is calculated, and the average of the obtained values is calculated.

　図２、図６及び図７に示すように、本実施形態にかかる光拡散装置１では、光ファイバ２０の先端部２０ＴＥに、コア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面２０ｅを有している。端面２０ｅは、光ファイバ２０の中途で斜めにカットすることで設けることができる。平面Ｐと端面２０ｅとの成す角θは、光ファイバ２０で伝送されるレーザ光が全反射する最小角度以上でも未満でも構わないが、光ファイバ２０で伝送されるレーザ光が全反射する最小角度未満とすることで、反射方向と逆方向にレーザ光を漏出させることができる。具体的には、光ファイバのコアの屈折率ｎｃｏｒｅ、空気の屈折率をｎａｉｒとするとθ＝ａｒｃｓｉｎ（ｎａｉｒ/ｎｃｏｒｅ）となり、ｎｃｏｒｅ＝１．４６５、ｎａｉｒ＝１．０とするとθ＝４３度となる。 2, 6, and 7, in the light diffusion device 1 according to this embodiment, the tip 20TE of the optical fiber 20 has an end face 20e that is oblique to the plane P perpendicular to the axis 21A of the core 21. The end face 20e can be provided by cutting the optical fiber 20 at an angle in the middle. The angle θ between the plane P and the end face 20e can be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected, but by making the angle θ less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected, the laser light can leak in the opposite direction to the reflection direction. Specifically, if the refractive index of the core of the optical fiber is ncore and the refractive index of air is nair, then θ = arcsin(nair/ncore), and if ncore = 1.465 and nair = 1.0, then θ = 43 degrees.

　本実施形態にかかる光拡散装置１において、光源１０を作動させ光ファイバ２０の基端部２０ＢＥからレーザ光を入射させると、レーザ光は光伝送部２０ａを伝送され、光出射部２０ｂから出射する。光出射部２０ｂにおいて、光ファイバ２０の先端部２０ＴＥは、既述の如くコア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面２０ｅを有しており、当該端面２０ｅでレーザ光が反射する。端面２０ｅで反射したレーザ光は、図２の矢印Ｌ２に示すように側方に照射される。したがって、側方へのレーザ光の照射効率を向上させることができる（効果１）。 In the light diffusing device 1 according to this embodiment, when the light source 10 is operated to cause laser light to be incident on the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b. In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has an end face 20e that is inclined with respect to the plane P perpendicular to the axis 21A of the core 21 as described above, and the laser light is reflected by the end face 20e. The laser light reflected by the end face 20e is irradiated laterally as shown by the arrow L2 in FIG. 2. Therefore, the efficiency of irradiating the laser light laterally can be improved (effect 1).

　また、既述の通り、本実施形態にかかる光拡散装置１において、光出射部２０ｂにおけるクラッド２２ｂの外径Ｄｂが、光伝送部２０ａにおけるクラッド２２ａの外径Ｄａよりも、光伝送部２０ａを伝送される光の波長λの大きさ以上に小さく（Ｄｂ≦Ｄａ－λ）なるようにしていることにより、この薄膜のクラッド２２ｂの領域においても、図２の矢印Ｌ１に示すようにレーザ光が側方に照射される（効果２）。 As described above, in the light diffusing device 1 according to the present embodiment, the outer diameter Db of the cladding 22b in the light emitting portion 20b is smaller than the outer diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength λ of the light transmitted through the light transmitting portion 20a (Db≦Da−λ). As a result, even in the region of the thin cladding 22b, the laser light is irradiated laterally as shown by the arrow L1 in FIG. 2 (Effect 2).

　さらに、本実施形態では、クラッド２２ｂの薄膜化とともに光ファイバ２０の先端部２０ＴＥを斜めにカットした斜めの端面２０ｅを有するため、光ファイバ２０の直径が狭くなり、光ファイバ２０内に光を閉じ込めにくくなっている。そのため、光は側方から漏れ出やすくなり、結果として、側方へのレーザ光の照射効率を向上させることができる（効果３）。 Furthermore, in this embodiment, the cladding 22b is thinned and the tip 20TE of the optical fiber 20 has an oblique end face 20e cut at an angle, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light within the optical fiber 20. This makes it easier for light to leak out from the sides, and as a result, the efficiency of irradiating the laser light to the sides can be improved (Effect 3).

　即ち、本実施形態によれば、光ファイバ２０の先端部２０ＴＥを斜めにカットすることによる側方照射効果（効果１）と、光出射部２０ｂにおけるクラッド２２ｂを適切に薄膜化することによる側方照射効果（効果２）と、を単に足し合わせた効果に留まらず、両構成を有機的に結び付けたことによる、新たな複合的な側方照射効果（効果３）が顕著な効果として奏される。 In other words, this embodiment does not merely combine the side illumination effect (effect 1) of cutting the tip 20TE of the optical fiber 20 at an angle with the side illumination effect (effect 2) of appropriately thinning the cladding 22b in the light emitting portion 20b, but also provides a new, complex side illumination effect (effect 3) by organically linking the two configurations.

　これら効果については、後述する実施例において具体的に検証している。後述する実施例において明らかな通り、新たな複合的な側方照射効果（効果３）は、クラッド薄膜化に基づく側方照射効果（効果２）に比して、影響が大きい。また、クラッド薄膜化に基づく側面照射は、図２を見てもわかる通り、照射領域が光ファイバ２０の軸２１Ａ方向（長手方向）に延在してしまう。狭い照射領域に対して高い照射効率で光を照射するためには、クラッド２２を薄膜化して形成される光出射部２０ｂの軸２１Ａ方向（長手方向）長さは、短い方が好ましい。光出射部２０ｂとしては、具体的には、光ファイバ２０の先端側Ｔの例えば、４０ｍｍ以下の範囲内に形成されることが好ましく、１０ｍｍ以下の範囲内に形成されることがより好ましい。 These effects are specifically verified in the examples described later. As will be clear from the examples described later, the new composite side irradiation effect (Effect 3) has a greater impact than the side irradiation effect (Effect 2) based on the thinning of the cladding. In addition, as can be seen from FIG. 2, the side irradiation based on the thinning of the cladding results in the irradiation area extending in the axial 21A direction (longitudinal direction) of the optical fiber 20. In order to irradiate light with high irradiation efficiency to a narrow irradiation area, it is preferable that the length of the light emitting portion 20b formed by thinning the cladding 22 in the axial 21A direction (longitudinal direction) is short. Specifically, the light emitting portion 20b is preferably formed within a range of, for example, 40 mm or less from the tip side T of the optical fiber 20, and more preferably within a range of 10 mm or less.

　また、新たな複合的な側方照射効果（効果３）が奏されるためには、クラッド２２を薄膜化して形成される光出射部２０ｂが、光ファイバ２０の先端側Ｔにおいて、端面２０ｅに連なる領域まで延びていることが好ましい。 In addition, in order to achieve the new composite side illumination effect (Effect 3), it is preferable that the light emitting portion 20b formed by thinning the cladding 22 extends to a region adjacent to the end face 20e at the tip side T of the optical fiber 20.

＜第２の実施形態＞
　図８は第２の実施形態にかかる光拡散装置２における光ファイバの光出射部及びその近傍の要部断面図であり、図９は光拡散装置２における光ファイバの光出射部及びその近傍の拡大断面図であり、図１０は光拡散装置２における光ファイバの先端側から見た平面図（図８及び図９の紙面における右側方から見た図）である。本実施形態にかかる光拡散装置２は、第１の実施形態にかかる光拡散装置１とほぼ同様の構成であるため、光拡散装置２の概略については、図１を参照のこと。 Second Embodiment
Fig. 8 is a cross-sectional view of the light output portion of the optical fiber and its vicinity in the light diffusing device 2 according to the second embodiment, Fig. 9 is an enlarged cross-sectional view of the light output portion of the optical fiber and its vicinity in the light diffusing device 2, and Fig. 10 is a plan view (viewed from the right side on the paper surface of Figs. 8 and 9) seen from the tip side of the optical fiber in the light diffusing device 2. Since the light diffusing device 2 according to this embodiment has a configuration almost similar to that of the light diffusing device 1 according to the first embodiment, refer to Fig. 1 for an outline of the light diffusing device 2.

　また、図８におけるＥ－Ｅ断面は図４と、Ｆ－Ｆ断面は図３と、それぞれ同一なので、これら断面は図３乃至図４を参照のこと。なお、第２の実施形態にかかる光拡散装置２は、光ファイバ２０の先端部２０ＴＥの形状が本実施形態に特有である点を除き、第１の実施形態にかかる光拡散装置１と同様の構成であるため、第１の実施形態にかかる光拡散装置１と同一の機能を備える部材には、図１～図７と同一の符号を付して、その説明を省略する。 In addition, the E-E cross section in FIG. 8 is the same as FIG. 4, and the F-F cross section is the same as FIG. 3, so please refer to FIG. 3 and FIG. 4 for these cross sections. Note that the light diffusion device 2 according to the second embodiment has the same configuration as the light diffusion device 1 according to the first embodiment, except that the shape of the tip portion 20TE of the optical fiber 20 is unique to this embodiment. Therefore, the members having the same functions as the light diffusion device 1 according to the first embodiment are given the same reference numerals as in FIG. 1 to FIG. 7, and their description will be omitted.

　図８～図１０に示すように、本実施形態にかかる光拡散装置２では、光ファイバ２０の先端部２０ＴＥに、コア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面を２０ｅ１及び２０ｅ２の一対（２つ）有している。このとき、当該平面Ｐと端面２０ｅ１との成す角γ、及び、平面Ｐと端面２０ｅ２との成す角δは、何れも、光ファイバ２０で伝送されるレーザ光が全反射する最小角度以上でも未満でも構わない。 As shown in Figures 8 to 10, in the light diffusion device 2 according to this embodiment, the tip 20TE of the optical fiber 20 has a pair (two) end faces 20e1 and 20e2 that are inclined with respect to a plane P perpendicular to the axis 21A of the core 21. In this case, the angle γ between the plane P and the end face 20e1, and the angle δ between the plane P and the end face 20e2 can both be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected.

　本実施形態にかかる光拡散装置２において、光源１０を作動させ光ファイバ２０の基端部２０ＢＥからレーザ光を入射させると、レーザ光は光伝送部２０ａを伝送され、光出射部２０ｂから出射する。光出射部２０ｂにおいて、光ファイバ２０の先端部２０ＴＥは、既述の如くコア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面を一対有しており、当該端面２０ｅ１及び端面２０ｅ２でそれぞれ反射する。反射したレーザ光は、それぞれ矢印Ｌ２１方向及び矢印Ｌ２２方向に進む。したがって、本実施形態においては、一方とその反対方向の２方向の側方へのレーザ光の照射効率を向上させることができる（効果１）。 In the light diffusing device 2 according to the present embodiment, when the light source 10 is operated to cause laser light to be incident on the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b. In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has a pair of end faces that are inclined with respect to the plane P perpendicular to the axis 21A of the core 21 as described above, and is reflected by the end faces 20e1 and 20e2. The reflected laser light travels in the directions of the arrows L21 and L22 , respectively. Therefore, in the present embodiment, the irradiation efficiency of the laser light in two lateral directions, one direction and the opposite direction, can be improved (Effect 1).

　また、既述の通り、本実施形態にかかる光拡散装置２において、光出射部２０ｂにおけるクラッド２２ｂの外径Ｄｂが、光伝送部２０ａにおけるクラッド２２ａの外径Ｄａよりも、光伝送部２０ａを伝送される光の波長λの大きさ以上に小さく（Ｄｂ≦Ｄａ－λ）なるようにしていることにより、この薄膜のクラッド２２ｂの領域においても、図８の矢印Ｌ１に示すようにレーザ光が、前記一方とその反対方向の２方向を含む側方に照射される（効果２）。 As described above, in the light diffusing device 2 according to the present embodiment, the outer diameter Db of the cladding 22b at the light output portion 20b is smaller than the outer diameter Da of the cladding 22a at the light transmission portion 20a by at least the wavelength λ of the light transmitted through the light transmission portion 20a (Db≦Da−λ). As a result, even in the region of the cladding 22b of this thin film, the laser light is irradiated laterally in two directions, that is, the one direction and the opposite direction, as shown by the arrow L1 in FIG. 8 (Effect 2).

　さらに、本実施形態においても、クラッド２２ｂの薄膜化とともに光ファイバ２０の先端部２０ＴＥを斜めにカットした斜めの端面２０ｅ１及び端面２０ｅ２を有するため、光ファイバ２０の直径が狭くなり光が閉じ込められにくく側方から漏れ出やすくなり、側方へのレーザ光の照射効率を向上させることができる（効果３）。 Furthermore, in this embodiment, the cladding 22b is thinned and the tip 20TE of the optical fiber 20 is cut at an angle to have the slanted end faces 20e1 and 20e2, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light and easier for it to leak out from the sides, thereby improving the efficiency of lateral laser light irradiation (Effect 3).

　即ち、本実施形態によれば、第１の実施形態と同様、光ファイバ２０の先端部２０ＴＥを斜めにカットすることによる側方照射効果（効果１）と、光出射部２０ｂにおけるクラッド２２ｂを適切に薄膜化することによる側方照射効果（効果２）と、これらの構成を有機的に結び付けたことによる、新たな複合的な側方照射効果（効果３）と、が顕著な効果として奏される。 In other words, according to this embodiment, as in the first embodiment, the remarkable effects are the lateral irradiation effect (effect 1) obtained by cutting the tip 20TE of the optical fiber 20 at an angle, the lateral irradiation effect (effect 2) obtained by appropriately thinning the cladding 22b in the light emitting portion 20b, and the new composite lateral irradiation effect (effect 3) obtained by organically linking these configurations.

　また、本実施形態によれば、光ファイバ２０の先端部２０ＴＥの斜めカットの端面を一対（２つ）設けているため、一方とその反対方向の２方向の側方に対して、レーザ光の照射効率を向上させることができる。例えば、体内を照射したり、体内から体表面に投影させたりする用途で本実施形態にかかる光拡散装置２を用いた場合、光ファイバ２０の軸２１Ａを軸として回転させて照射方向を調整する際に、一方とその反対方向の２方向のうち何れか近い方の側方照射方向に合わせればよい。そのため、本実施形態にかかる光拡散装置２は、前記用途において、特に好適である。なお、光ファイバ２０の先端部２０ＴＥの斜めカットの端面の数としては、本実施形態の如き２つに限定されず、３つ以上でも構わない。 In addition, according to this embodiment, since a pair (two) of obliquely cut end faces are provided at the tip 20TE of the optical fiber 20, the irradiation efficiency of the laser light can be improved in two lateral directions, one direction and the opposite direction. For example, when the light diffusion device 2 according to this embodiment is used for irradiating the inside of a body or projecting light from inside the body onto the body surface, when adjusting the irradiation direction by rotating the optical fiber 20 around the axis 21A of the optical fiber 20, it is sufficient to align it with the closer lateral irradiation direction of either of the two directions, one direction and the opposite direction. Therefore, the light diffusion device 2 according to this embodiment is particularly suitable for the above-mentioned applications. Note that the number of obliquely cut end faces at the tip 20TE of the optical fiber 20 is not limited to two as in this embodiment, and may be three or more.

　その他、構成の詳細や具体例等は、第１の実施形態と同様であるため、説明を省略する。 Other details of the configuration and specific examples are the same as those in the first embodiment, so the explanation will be omitted.

＜第３の実施形態＞
　図１１は第３の実施形態にかかる光拡散装置３における光ファイバの光出射部及びその近傍の要部断面図であり、図１２は光拡散装置３における光ファイバの光出射部及びその近傍の拡大断面図であり、図１３は光拡散装置３における光ファイバの光出射部及びその近傍の斜視図である。本実施形態にかかる光拡散装置３は、第１の実施形態にかかる光拡散装置１とほぼ同様の構成であるため、光拡散装置３の概略については、図１を参照のこと。 Third Embodiment
Fig. 11 is a cross-sectional view of a main part of a light output portion of an optical fiber and its vicinity in a light diffusing device 3 according to the third embodiment, Fig. 12 is an enlarged cross-sectional view of a light output portion of an optical fiber and its vicinity in the light diffusing device 3, and Fig. 13 is a perspective view of a light output portion of an optical fiber and its vicinity in the light diffusing device 3. Since the light diffusing device 3 according to this embodiment has a configuration substantially similar to that of the light diffusing device 1 according to the first embodiment, refer to Fig. 1 for an outline of the light diffusing device 3.

　また、図１１におけるＧ－Ｇ断面は図４と、Ｈ－Ｈ断面は図３と、それぞれ同一なので、これら断面は図３乃至図４を参照のこと。なお、第３の実施形態にかかる光拡散装置３は、光ファイバ２０の先端部２０ＴＥの形状が本実施形態に特有である点を除き、第１の実施形態にかかる光拡散装置１と同様の構成であるため、第１の実施形態にかかる光拡散装置１と同一の機能を備える部材には、図１～図７と同一の符号を付して、その説明を省略する。 In addition, the G-G cross section in FIG. 11 is the same as FIG. 4, and the H-H cross section is the same as FIG. 3, so please refer to FIG. 3 and FIG. 4 for these cross sections. Note that the light diffusion device 3 according to the third embodiment has the same configuration as the light diffusion device 1 according to the first embodiment, except that the shape of the tip portion 20TE of the optical fiber 20 is unique to this embodiment. Therefore, the members having the same functions as the light diffusion device 1 according to the first embodiment are given the same reference numerals as in FIG. 1 to FIG. 7, and their description will be omitted.

　図１１～図１３に示すように、本実施形態にかかる光拡散装置３では、光ファイバ２０の先端部２０ＴＥに、光ファイバ２０の周方向において連続的であり、かつ、形状が円錐形状である端面２０ｅ３を有している。このとき、当該平面Ｐと端面２０ｅ３との成す角σは、何れも、光ファイバ２０で伝送されるレーザ光が全反射する最小角度以上でも未満でも構わない。 As shown in Figures 11 to 13, in the light diffusion device 3 of this embodiment, the tip 20TE of the optical fiber 20 has an end face 20e3 that is continuous in the circumferential direction of the optical fiber 20 and has a conical shape. In this case, the angle σ between the plane P and the end face 20e3 can be greater than or less than the minimum angle at which the laser light transmitted by the optical fiber 20 is totally reflected.

　本実施形態にかかる光拡散装置２において、光源１０を作動させ光ファイバ２０の基端部２０ＢＥからレーザ光を入射させると、レーザ光は光伝送部２０ａを伝送され、光出射部２０ｂから出射する。光出射部２０ｂにおいて、光ファイバ２０の先端部２０ＴＥは、既述の如く光ファイバ２０の周方向において連続的であり、かつ、形状が円錐形状である端面２０ｅ３を有しており、当該端面２０ｅ３で反射する。反射したレーザ光は、軸２１Ａと交差する矢印Ｌ3方向に放射状に進む。したがって、本実施形態においては、側方へ放射状に進むレーザ光の照射効率を向上させることができる（効果１）。 In the light diffusing device 2 according to the present embodiment, when the light source 10 is operated to cause laser light to enter the base end 20BE of the optical fiber 20, the laser light is transmitted through the light transmitting section 20a and emitted from the light emitting section 20b. In the light emitting section 20b, the tip end 20TE of the optical fiber 20 has an end face 20e3 that is continuous in the circumferential direction of the optical fiber 20 and has a conical shape as described above, and is reflected by the end face 20e3. The reflected laser light travels radially in the direction of the arrow L3 that intersects with the axis 21A. Therefore, in this embodiment, the irradiation efficiency of the laser light that travels radially to the side can be improved (Effect 1).

　また、既述の通り、本実施形態にかかる光拡散装置３において、光出射部２０ｂにおけるクラッド２２ｂの外径Ｄｂが、光伝送部２０ａにおけるクラッド２２ａの外径Ｄａよりも、光伝送部２０ａを伝送される光の波長λの大きさ以上に小さく（Ｄｂ≦Ｄａ－λ）なるようにしていることにより、この薄膜のクラッド２２ｂの領域においても、図１１の矢印Ｌ１に示すようにレーザ光が、側方へ放射状に照射される（効果２）。 As described above, in the light diffusing device 3 according to the present embodiment, the outer diameter Db of the cladding 22b in the light emitting portion 20b is smaller than the outer diameter Da of the cladding 22a in the light transmitting portion 20a by at least the wavelength λ of the light transmitted through the light transmitting portion 20a (Db≦Da−λ). As a result, even in the region of the thin cladding 22b, the laser light is irradiated radially to the side, as shown by the arrow L1 in FIG. 11 (Effect 2).

　さらに、本実施形態においても、クラッド２２ｂの薄膜化とともに光ファイバ２０の先端部２０ＴＥを斜めにカットした斜めの端面２０ｅ３を有するため、光ファイバ２０の直径が狭くなり光が閉じ込められにくく側方へ放射状に漏れ出やすくなり、側方へ放射状に進むレーザ光の照射効率を向上させることができる（効果３）。 Furthermore, in this embodiment, the cladding 22b is thinned and the tip 20TE of the optical fiber 20 has an oblique end face 20e3 cut at an angle, so the diameter of the optical fiber 20 is narrowed, making it difficult to confine light and allowing it to easily leak out radially to the side, improving the irradiation efficiency of the laser light that travels radially to the side (Effect 3).

　即ち、本実施形態によれば、第１の実施形態と同様、光ファイバ２０の先端部２０ＴＥを斜めにカットすることによる側方照射効果（効果１）と、光出射部２０ｂにおけるクラッド２２ｂを適切に薄膜化することによる側方照射効果（効果２）と、これらの構成を有機的に結び付けたことによる、新たな複合的な側方照射効果（効果３）と、が顕著な効果として奏される。 In other words, according to this embodiment, as in the first embodiment, the remarkable effects are the lateral irradiation effect (effect 1) obtained by cutting the tip 20TE of the optical fiber 20 at an angle, the lateral irradiation effect (effect 2) obtained by appropriately thinning the cladding 22b in the light emitting portion 20b, and the new composite lateral irradiation effect (effect 3) obtained by organically linking these configurations.

　また、本実施形態によれば、光ファイバ２０の周方向において連続的であり、かつ、形状が円錐形状である端面２０ｅ３を設けているため、側方の全周に対して、レーザ光の照射効率を向上させることができる。例えば、第２の実施形態と同様、体内を照射したり、体内から体表面に投影させたりする用途で本実施形態にかかる光拡散装置３を用いた場合、光ファイバ２０の軸２１Ａを中心として全周方向に放射状に照射されるため、軸２１Ａを中心とした回転方向の照射位置合わせが必要ない。そのため、本実施形態にかかる光拡散装置３は、前記用途において、特に好適である。 Furthermore, according to this embodiment, the end face 20e3 is continuous in the circumferential direction of the optical fiber 20 and has a conical shape, so that the irradiation efficiency of the laser light can be improved for the entire lateral circumference. For example, as in the second embodiment, when the light diffusion device 3 of this embodiment is used for irradiating the inside of a body or projecting light from inside the body onto the body surface, irradiation is performed radially in the entire circumferential direction centered on the axis 21A of the optical fiber 20, so there is no need to align the irradiation position in the rotational direction centered on the axis 21A. Therefore, the light diffusion device 3 of this embodiment is particularly suitable for the above-mentioned applications.

　その他、変形例や各部材の材質等は、第１の実施形態と同様であるため、説明を省略する。 Other modifications and the materials of each component are the same as in the first embodiment, so explanations will be omitted.

＜光拡散装置の用途＞
　以上説明した実施形態にかかる光拡散装置は、そのまま、あるいは適宜他の装備品等と共に体内に挿入して、患部等にレーザ光を照射するディフューザとして用いることができる。 <Applications of light diffusion devices>
The light diffusion device according to the embodiment described above can be inserted into the body as it is or together with other accessories as appropriate, and used as a diffuser for irradiating an affected area with laser light.

　また、以上説明した実施形態にかかる光拡散装置は、内視鏡やカテーテル等と共に体内に挿入して、体内を照射したり、体内から体表面に投影させたりする、いわゆる照明として用いることもできる。これらの中で、カテーテル等と共に用いる用途について、以下、説明する。 The light diffusion device according to the embodiment described above can also be inserted into the body together with an endoscope, catheter, or the like, and used as a so-called light source to illuminate the inside of the body or project light onto the body surface from inside the body. Among these, the use together with a catheter or the like will be described below.

　図１４は、第１の実施形態にかかる光拡散装置１を例に挙げ、カテーテルと共に用いた場合の医療用カテーテルセット３０の使用例を示す概略図である。医療用カテーテルセット３０は、カテーテル２６と、光拡散装置１と、を備えるものであり、図１４に示す通り、使用時には、光拡散装置１の光ファイバ２０をカテーテル２６内に挿入した状態で施術者の利用に供される。 FIG. 14 is a schematic diagram showing an example of the use of a medical catheter set 30 when the light diffusion device 1 according to the first embodiment is used together with a catheter. The medical catheter set 30 includes a catheter 26 and a light diffusion device 1, and as shown in FIG. 14, when in use, the optical fiber 20 of the light diffusion device 1 is inserted into the catheter 26 and is available to the practitioner.

　例えば、医療用カテーテルセット３０の先端側Ｔから、内視鏡と共に体内に挿入し、光出射部２０ｂから光を照射して内視鏡で体内を観察しながら、カテーテル２６の先端を目的の場所に導くことができる。あるいは、内視鏡無しに体内に挿入し、光出射部２０ｂから光を体内に照射し、体表面に投影させて、カテーテル２６の先端位置を体外から確認しながら、当該先端位置を目的の場所に導くことができる。 For example, the medical catheter set 30 can be inserted into the body together with an endoscope from the tip side T, and the tip of the catheter 26 can be guided to the desired location while observing the inside of the body with the endoscope by irradiating light from the light emitting unit 20b. Alternatively, the catheter can be inserted into the body without an endoscope, and light can be irradiated into the body from the light emitting unit 20b and projected onto the body surface, allowing the position of the tip of the catheter 26 to be confirmed from outside the body while the tip position is guided to the desired location.

　施術者は、カテーテル２６の先端を目的の場所に導いた後、光拡散装置１の光ファイバ２０をカテーテル２６から引き抜き、カテーテル２６を目的の医療用途として用いて医療行為を行えばよい。 After guiding the tip of the catheter 26 to the desired location, the practitioner can pull out the optical fiber 20 of the light diffusion device 1 from the catheter 26 and use the catheter 26 for the desired medical purpose to perform the medical procedure.

　なお、図１４に示す使用例においては、カテーテル２６として光透過性の材質のチューブを用いた場合を想定しているため、光ファイバ２０の先端部２０ＴＥがカテーテル２６の管内に収まった状態で用いている。カテーテル２６として光非透過性の材質のチューブを用いた場合には、光ファイバ２０の先端部２０ＴＥをカテーテル２６の先端から突き出させて光出射部２０ｂの少なくとも一部を露出させたり、あるいは、光ファイバ２０の先端部２０ＴＥをカテーテル２６の先端開口の近傍に位置させて、光出射部２０ｂから出射する光をカテーテル２６の先端開口から漏れ出させたりすればよい。 In the example of use shown in FIG. 14, it is assumed that a tube made of a light-transmitting material is used as the catheter 26, and therefore the tip 20TE of the optical fiber 20 is used in a state where it is fitted inside the tube of the catheter 26. If a tube made of a light-impermeable material is used as the catheter 26, the tip 20TE of the optical fiber 20 may be protruded from the tip of the catheter 26 to expose at least a part of the light emitting portion 20b, or the tip 20TE of the optical fiber 20 may be positioned near the tip opening of the catheter 26 to allow the light emitted from the light emitting portion 20b to leak out from the tip opening of the catheter 26.

　以上説明した実施形態は、本発明の代表的な形態の例を示したに過ぎず、本発明は、これら実施形態に限定されるものではない。即ち、当業者は、従来公知の知見に従い、本発明の骨子を逸脱しない範囲で種々変形して実施することができる。かかる変形によってもなお本発明の光拡散装置あるいはこれを備える医療用カテーテルセットの構成を具備する限り、勿論、本発明の範疇に含まれるものである。 The above-described embodiments merely show examples of typical forms of the present invention, and the present invention is not limited to these embodiments. In other words, a person skilled in the art can implement the present invention by making various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as such modifications still provide the configuration of the light diffusion device of the present invention or a medical catheter set equipped with the same, they will of course be included in the scope of the present invention.

　例えば、上記実施形態においては、光出射部２０ｂのクラッド２２の外周側に位置する部分を周方向にわたって除去するようにしたものを示したが、これに限られるものではない。光出射部２０ｂの外周面からレーザ光を出射させる光ファイバであれば、図１５に示すように、光出射部２０ｂのクラッド２２の外周側に位置する部分における、周方向の一部分のみを除去し、周方向の一部分のみからレーザ光を出射させるようにしてもよい。即ち、光出射部は、光ファイバの先端側の周方向における少なくとも一部に形成されていればよい。 For example, in the above embodiment, the portion of the light emitting portion 20b located on the outer periphery of the clad 22 is removed in the circumferential direction, but this is not limited to the above. In the case of an optical fiber that emits laser light from the outer periphery of the light emitting portion 20b, as shown in FIG. 15, only a portion of the portion of the light emitting portion 20b located on the outer periphery of the clad 22 may be removed in the circumferential direction, so that the laser light is emitted from only a portion of the circumferential direction. In other words, it is sufficient that the light emitting portion is formed in at least a portion of the circumferential direction on the tip side of the optical fiber.

　光出射部は、光ファイバの先端側の周方向における３０％以上の部分に形成されていればよく、例えば、光ファイバの先端側の周方向における１２０度～１８０度の範囲内に形成されていてもよい。また、光出射部は、光ファイバの先端側の周方向に離散的に形成されていてもよく、合計の面積が光ファイバの先端部の外周面の全面積における３０％以上であればよい。 The light emitting portion may be formed in a portion that covers 30% or more of the circumference of the tip side of the optical fiber, for example, within a range of 120 degrees to 180 degrees in the circumference of the tip side of the optical fiber. The light emitting portions may also be formed discretely in the circumference of the tip side of the optical fiber, and their total area may be 30% or more of the total area of the outer circumferential surface of the tip part of the optical fiber.

　光ファイバの先端部の外周面における光出射部の面積は、光ファイバを切断した複数の断面をＳＥＭ（走査型電子顕微鏡）等で観察し、全周長に対するクラッドが除去された領域の合計長さの割合を求め、これを平均することで求めることができる。 The area of the light emitting portion on the outer surface of the tip of the optical fiber can be calculated by observing multiple cross sections of the cut optical fiber using a SEM (scanning electron microscope) or similar, calculating the ratio of the total length of the area where the cladding has been removed to the total circumference, and averaging these.

　図２及び図１５を参照して説明すると、光ファイバ２０を２０ｂの領域で複数（例えば３カ所）切断し、その断面をＳＥＭで観察する。そして、凹凸面２２ｆとなっている薄膜のクラッド２２の領域の全周長に対する割合をそれぞれ求める。図１５の断面においては５０％である。得られた複数の断面の値を平均することによって、光ファイバの先端部の外周面における光出射部の面積が求められる。 Referring to Figures 2 and 15, the optical fiber 20 is cut in the region 20b in multiple places (e.g., three places) and the cross sections are observed with an SEM. The proportion of the region of the thin cladding 22 that forms the uneven surface 22f to the total perimeter is then calculated. In the cross section of Figure 15, it is 50%. The area of the light emitting portion on the outer periphery of the tip of the optical fiber is calculated by averaging the values obtained for the multiple cross sections.

　また、上記実施形態においては、光出射部２０ｂにおける光ファイバ２０の外表面に凹凸が形成されている例を挙げているが、凹凸が全く、あるいはほとんど無い外表面であっても、本発明による効果は期待できる。ただし、光出射部２０ｂにおける光ファイバ２０の外表面に凹凸が形成されていることが、側方への放射効率の向上や、等方性の点で好ましい。ここで、「凹凸」とは、凹凸の最大の山のピークと最小の谷の底の差（輪郭曲線の最大高さ：ＪＩＳ　Ｂ０６０１参照）Ｒｚを示す。。 In addition, in the above embodiment, an example is given in which unevenness is formed on the outer surface of the optical fiber 20 at the light emitting portion 20b, but the effects of the present invention can be expected even if the outer surface has no or almost no unevenness. However, it is preferable to form unevenness on the outer surface of the optical fiber 20 at the light emitting portion 20b in terms of improving the lateral radiation efficiency and isotropy. Here, "unevenness" refers to the difference Rz between the maximum peak of the unevenness and the minimum valley bottom (maximum height of the contour curve: see JIS B0601).

　以下、実施例及び比較例を挙げて、本発明をより具体的に説明する。
　実施例１として、図１～図７に示す第１の実施形態と同様の光拡散装置１を含む図１５に示す医療用カテーテルセット３０及び光源１０を用意した。実施例１の具体的な仕様及び条件は、以下の通りである。なお、以下に記載のない仕様及び条件は、既述の第１の実施形態の説明の中で記した通りである。 The present invention will be described more specifically below with reference to examples and comparative examples.
As Example 1, a medical catheter set 30 and a light source 10 shown in Fig. 15 including a light diffusion device 1 similar to those of the first embodiment shown in Figs. 1 to 7 were prepared. The specific specifications and conditions of Example 1 are as follows. Note that specifications and conditions not described below are as described in the description of the first embodiment above.

（実施例１の仕様・条件）
・光出射部２０ｂの軸２１Ａ方向長さ：５ｍｍ
・光出射部２０ｂにおいて、クラッド２２ｂの厚さｔが１μｍ以上である面積割合：３０％
・クラッド２２の除去方法：エッチング５秒
・成す角θ：６０°
・カテーテル２６の軸２１Ａ方向長さ：２０００ｍｍ
・カテーテル２６の材質、内径、外径：ナイロン製（透明）、１ｍｍ、１．１ｍｍ
・光ファイバ２０の全長：２０００ｍｍ
・光源１０の光の波長：６３０ｎｍ
・光源１０の光の強度：１．０～５００ｍＷ (Specifications and conditions of Example 1)
Length of the light emitting portion 20b in the direction of the axis 21A: 5 mm
The percentage of the area of the light emitting portion 20b where the thickness t of the cladding 22b is 1 μm or more: 30%
Method for removing cladding 22: Etching for 5 seconds Angle θ: 60°
Length of catheter 26 in the axial direction 21A: 2000 mm
Material, inner diameter, outer diameter of catheter 26: Nylon (transparent), 1 mm, 1.1 mm
Total length of optical fiber 20: 2000 mm
Wavelength of light from light source 10: 630 nm
Light intensity of light source 10: 1.0 to 500 mW

　また、上記実施例１の構成から、光ファイバ２０の先端部２０ＴＥを斜めカットせず、コア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面を設けないことを除き、他は実施例１と同一の仕様・条件の装置を用意し、これを比較例１の光拡散装置とした。 In addition, from the configuration of Example 1 above, except that the tip 20TE of the optical fiber 20 is not cut at an angle, and an end face is not provided at an angle with respect to the plane P perpendicular to the axis 21A of the core 21, a device with the same specifications and conditions as Example 1 was prepared, and this was used as the light diffusion device of Comparative Example 1.

　それとは別に、上記実施例１の構成から、エッチングを施さないでクラッド２２を除去せず、光出射部２０ｂを設けなかったことを除き、他は実施例１と同一の仕様・条件の装置を用意し、これを比較例２の光拡散装置とした（コア２１の軸２１Ａに垂直の平面Ｐに対して斜めの端面は設けた。）。 Separately from the configuration of Example 1 above, a device with the same specifications and conditions as Example 1 was prepared, except that etching was not performed to remove the cladding 22, and no light emitting portion 20b was provided, and this was used as the light diffusion device of Comparative Example 2 (an end face was provided that was oblique to the plane P perpendicular to the axis 21A of the core 21).

　実施例１及び比較例１及び２の光拡散装置について、それぞれ、上記仕様・条件で、光源１０を作動させて、光ファイバ２０の基端部２０ＢＥから光を入射させ、光出射部２０ｂ（比較例２においては、２０ｂに相当する箇所。以下同じ。）から出射（照射）させた。この時、光出射部２０ｂの側面から軸２１Ａと垂直の特定の方向に１ｍｍ離れた位置（側方成分測定）と、光ファイバ２０の先端部２０ＴＥから軸２１Ａと垂直の方向に１ｍｍ離れた位置（直射成分測定）に、受光径３ｍｍの光量計（ソーラボ社製、Ｓ１５１Ｃ）を置いて、光量を測定した。側方成分測定は、２カ所で行い、その平均を測定値とした。結果は、下記表１に示す通りである。 For the light diffusion devices of Example 1 and Comparative Examples 1 and 2, the light source 10 was operated under the above specifications and conditions to cause light to enter from the base end 20BE of the optical fiber 20 and exit (irradiate) from the light exit portion 20b (the portion corresponding to 20b in Comparative Example 2; the same applies below). At this time, a light receiving diameter of 3 mm (S151C, manufactured by Thorlabs) was placed at a position 1 mm away from the side of the light exit portion 20b in a specific direction perpendicular to the axis 21A (lateral component measurement) and at a position 1 mm away from the tip end 20TE of the optical fiber 20 in a direction perpendicular to the axis 21A (direct component measurement) to measure the amount of light. The lateral component measurement was performed at two locations, and the average was taken as the measured value. The results are shown in Table 1 below.

Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001

　上記表１を見ればわかる通り、斜めの端面を設けていない比較例１では側方成分の光があまり検出できず、クラッド２２を薄膜化しない比較例２では、ある程度側方成分の光を検出できたものの、実施例１に比べるとかなり小さかった。 As can be seen from Table 1 above, in Comparative Example 1, which does not have an oblique end face, very little lateral light component was detected, and in Comparative Example 2, in which the cladding 22 was not thinned, some lateral light component was detected, but it was significantly smaller than in Example 1.

　これに対して、実施例１では、直射成分に対して高い割合で側方成分の光が検出できていることがわかる。実施例１は、比較例１と比較例２の構成を併せ持つものであるが、比較例１と比較例２の構成を単に足し合わせた効果に留まらず、格段に高い側方照射効率を実現できている。 In contrast, it can be seen that in Example 1, a high ratio of lateral light components can be detected compared to the direct light components. Example 1 combines the configurations of Comparative Examples 1 and 2, but it does not merely achieve the effect of combining the configurations of Comparative Examples 1 and 2; it also achieves a significantly higher lateral illumination efficiency.

１，２，３　光拡散装置、
１０　光源、
２０　光ファイバ、
２０ａ　光伝送部、
２０ｂ　光出射部、
２０ｅ，２０ｅ１，２０ｅ２，２０ｅ３　端面、
２０ＢＥ　基端部、
２０ＴＥ　先端部、
２１　コア、
２２，２２ａ，２２ｂ　クラッド、
２２ｆ　凹凸面、
２６　カテーテル、
３０　医療用カテーテルセット 1, 2, 3 Light diffusion device,
10 light source,
20 optical fiber,
20a optical transmission unit,
20b light emitting portion,
20e, 20e1, 20e2, 20e3 end face,
20BE base end,
20TE tip,
21 cores,
22, 22a, 22b clad,
22f uneven surface,
26 catheter,
30 Medical catheter set

Claims (10)

　径方向の中心側に位置するコアと、前記コアの外周側に位置するクラッドと、からなる光ファイバを備え、前記光ファイバの基端部から入射した光を、前記光ファイバの先端側から出射させる光拡散装置であって、
　基端部から入射した光を先端部に向かって伝送する光伝送部と、先端側における前記クラッドの外周側に位置する部分を除去した光出射部と、を有し、
　前記光出射部における前記クラッドの外径Ｄｂが、前記光伝送部における前記クラッドの外径Ｄａよりも、前記光伝送部を伝送される光の波長λの大きさ以上に小さく（Ｄｂ≦Ｄａ－λ）、かつ、
　前記光ファイバの先端側の端部に、前記コアの軸に垂直の平面に対して斜めの端面を有する、光拡散装置。 A light diffusing device comprising an optical fiber having a core located at a radial center side and a clad located on an outer peripheral side of the core, the light diffusing device diffusing light incident on a base end of the optical fiber being emitted from a tip end side of the optical fiber,
a light transmitting section that transmits light incident from a base end section toward a tip end section, and a light emitting section that is formed by removing a portion located on an outer circumferential side of the clad on the tip side,
The outer diameter Db of the cladding in the light emitting portion is smaller than the outer diameter Da of the cladding in the light transmitting portion by at least the wavelength λ of the light transmitted through the light transmitting portion (Db≦Da−λ), and
A light diffusing device, comprising an end face at a tip end of the optical fiber, the end face being inclined with respect to a plane perpendicular to the axis of the core. 　前記光出射部における前記クラッドの厚さが、前記光出射部の全面積における３０％以上の領域で１μｍ以上である、請求項１に記載の光拡散装置。 The light diffusion device of claim 1, wherein the thickness of the cladding in the light output section is 1 μm or more in an area that is 30% or more of the total area of the light output section. 　前記光出射部が、前記光ファイバの先端側において、前記端面に連なる領域まで延びている、請求項１に記載の光拡散装置。 The light diffusion device of claim 1, wherein the light emitting portion extends to a region adjacent to the end face at the tip side of the optical fiber. 　前記光ファイバの先端側の端部に、前記コアの軸に垂直の平面に対して斜めの端面を２以上有する、請求項１に記載の光拡散装置。 The light diffusion device according to claim 1, wherein the tip end of the optical fiber has two or more end faces that are oblique with respect to a plane perpendicular to the axis of the core. 　前記端面が、前記光ファイバの周方向において連続的であり、かつ、当該端面の形状が円錐形状である、請求項１に記載の光拡散装置。 The light diffusion device of claim 1, wherein the end face is continuous in the circumferential direction of the optical fiber and has a conical shape. 　前記端面と前記コアの軸に垂直の平面との成す角が、前記光伝送部を伝送される光を全反射する最小角度未満である、請求項１に記載の光拡散装置。 The light diffusion device of claim 1, wherein the angle between the end face and a plane perpendicular to the axis of the core is less than the minimum angle at which light transmitted through the light transmission section is totally reflected. 　前記光ファイバが樹脂製の光ファイバである、請求項１に記載の光拡散装置。 The light diffusion device according to claim 1, wherein the optical fiber is a resin optical fiber. 　前記光ファイバの開口数（ＮＡ）が０．５以上である、請求項１に記載の光拡散装置。 The light diffusion device of claim 1, wherein the numerical aperture (NA) of the optical fiber is 0.5 or more. 　前記光出射部における前記光ファイバの外表面に、凹凸が形成されている、請求項１に記載の光拡散装置。 The light diffusion device according to claim 1, wherein the outer surface of the optical fiber in the light emitting section is formed with irregularities. 　カテーテルと、請求項１～９の何れかに記載の光拡散装置と、を備えた、医療用カテーテルセット。 A medical catheter set comprising a catheter and a light diffusion device according to any one of claims 1 to 9.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60250322A (en) * 1984-05-26 1985-12-11 Hirosada Hashimoto Laser beam irradiating fiber
US5537499A (en) * 1994-08-18 1996-07-16 Laser Peripherals, Inc. Side-firing laser optical fiber probe and method of making same
US5772657A (en) * 1995-04-24 1998-06-30 Coherent, Inc. Side firing fiber optic laser probe
JP2001502438A (en) * 1996-09-16 2001-02-20 フォーカル・インコーポレーテッド Optical fiber light scatterer and method of manufacturing the same
JP2006014776A (en) * 2004-06-30 2006-01-19 Manii Kk Optical fiber processing method and laser beam irradiation apparatus
US20110166562A1 (en) * 2010-01-04 2011-07-07 Ceramoptec Industries, Inc. High Durability Side Fire Optical Fiber for High Power Applications
US20120099112A1 (en) * 2010-10-25 2012-04-26 Gerard Argant Alphonse Multi-core low reflection lateral output fiber probe
WO2023100737A1 (en) * 2021-12-02 2023-06-08 古河電気工業株式会社 Light diffusion device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60250322A (en) * 1984-05-26 1985-12-11 Hirosada Hashimoto Laser beam irradiating fiber
US5537499A (en) * 1994-08-18 1996-07-16 Laser Peripherals, Inc. Side-firing laser optical fiber probe and method of making same
US5772657A (en) * 1995-04-24 1998-06-30 Coherent, Inc. Side firing fiber optic laser probe
JP2001502438A (en) * 1996-09-16 2001-02-20 フォーカル・インコーポレーテッド Optical fiber light scatterer and method of manufacturing the same
JP2006014776A (en) * 2004-06-30 2006-01-19 Manii Kk Optical fiber processing method and laser beam irradiation apparatus
US20110166562A1 (en) * 2010-01-04 2011-07-07 Ceramoptec Industries, Inc. High Durability Side Fire Optical Fiber for High Power Applications
US20120099112A1 (en) * 2010-10-25 2012-04-26 Gerard Argant Alphonse Multi-core low reflection lateral output fiber probe
WO2023100737A1 (en) * 2021-12-02 2023-06-08 古河電気工業株式会社 Light diffusion device

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