TW201237478A - Optical fiber and laser machining apparatus therewith - Google Patents

Abstract

In a laser machining apparatus, laser beam (L1) output from a laser outputting unit (14, 100) is transmitted through optical fibers (12a-12g), and a laser beam (L2) exiting from the optical fibers is applied to a workpiece (W) by a laser exiting unit (20). The optical fibers (12a-12g) includes a first core (50), a first clad (52) for covering the first core (50), a second core (54) for covering the first clad (52), and a second clad (56) for covering the second core (54). Each of the first core (50) and the second core (54) is made of nondoped silica glass. Each of the first cladding (52) and the second cladding (56) has refractive index that is lower than that of the silica glass.

Description

20123747$ VI. Description of the Invention: [Technical Field] The present invention relates to a laser processing apparatus for propagating a laser and preparing the optical fiber. In particular, the first, the right, the μ, and the [previous technique] are widely used in the reinforcement of the metal (cut off the high-output laser light # # /要寺) (Yttn trace Aluminum_Garnet, YAG) laser plus The meteorite YAG laser processing apparatus is generally configured such that the laser light oscillated by the oscillating oscillating device emits the laser from the optical system of the laser unit to such a field' (for example, refer to the Japanese patent) Kai Zhao 64·〇1〇7〇7 唬 报 Report) put forward the following technical ideas, the formation of boron trifluoride (BF3) and the nucleus of the nucleus _) The outer peripheral portion is covered with a core portion of the core portion formed purely by the core, and the outer peripheral portion of the core is folded at a refractive index of the center portion of the core. The sheep is low, however, for the light in the infrared region, the workpiece with high reflectance (= is easy to make the laser light of the base nucleus of the YAG*f projectile (the 附 (4) attached wave) is processed. The surface state of the workpiece, the difference in performance of the laser vibrating body itself (for example, the difference between the pulse and the diaphragm #), and the influence of the stability of the light-shaped shape are also large. σ As a method of stably processing the workpiece, for example, consideration is given to SHG (one-person 5fc white wave (sec_n (j_〇rder harmonic)) processing device or thinking 201237478 hybrid laser processing device (shlash of SHG laser light and basic wave), etc., but using SHG processing In the case of a device, it is difficult to increase the output of the laser light. On the other hand, when a hybrid laser processing apparatus is used, there is a problem that the cost is still >. Therefore, it is sought to develop a mine using the above basic wave. A mechanism for illuminating the workpiece stably. Here, taking an optical fiber as an example, if an incident angle of the laser light of the optical fiber, an incident numerical aperture (NA), and a bending degree of the optical fiber are divided In the optical fiber described in the above-mentioned Japanese Patent Publication No. Sho 64-010707, the 'for example' is incident on the Gaussian distribution. In the case of laser light, 'is in the process of propagating in the fiber, the intensity of the laser light is averaged, so the peak intensity is also reduced. And 'if the peak intensity of the laser light on the workpiece is reduced to less than the above workpiece The reaction threshold (reactiomhreshold value) (the lowest intensity value that can be processed) may not be processed. The center portion of the laser light (the peak intensity and its vicinity) is also included. When the optical fiber is incident on the optical fiber, the peak intensity can be suppressed from decreasing. However, in this case, since the outer peripheral portion (the portion other than the central portion) of the laser light is not incident on the optical fiber, the output of the laser light is lowered. The present invention has been made in view of the above problems, and an object of the invention is to provide a method for suppressing a decrease in peak intensity without reducing the output of laser light. The basic wave laser light can be used to stably process the high reflectivity workpiece of the optical fiber of 201237478 and the laser processing apparatus having the same. [1] The optical fiber of the present invention is used for propagating laser light, and is characterized by comprising: a first core, a first cladding covering the first core, a second core covering the first cladding, and a second cladding covering the second core, and the first fiber The core and the second core include undoped quartz glass. The first cladding layer and the second cladding layer have a refractive index lower than a refractive index of the non-seeded quartz glass. When the Gaussian-distributed laser light is incident on one end surface of the optical fiber, the first core portion can be used to propagate the core portion of the laser light, and the second fiber core can be used to propagate the outer peripheral portion of the laser light. Thereby, the output of the laser light is not lowered, and the peak intensity is suppressed from being lowered. Therefore, when a high-reflectance workpiece is processed using laser light of a fundamental wave, the peak intensity of the laser light on the workpiece can be made higher than the reaction threshold without lowering the output of the laser light. The workpiece can be processed stably. Further, since the first core and the second core are made of undoped quartz glass, the energy loss of the laser light propagating in the first core and the second core is appropriately suppressed. [2] In the above optical fiber, the first cladding layer and the second cladding layer may be formed by doping fluorine into quartz glass. According to this configuration, since the i-th cladding layer and the second cladding layer are formed by doping fluorine into the quartz glass, the first layer can be made! The cladding layer and the refractive index of the second cladding layer are appropriately lower than those of the undoped quartz glass (the first core and the second core). Further, the durability (the laser light intensity) of the laser light for the i-th cladding layer and the sixth layer 201237478 ^ 2 cladding layer can be made substantially the same as that of the undoped quartz glass. However, the laser light incident on the end surface of the optical fiber is divided into a portion (first laser light) incident on the first core, a portion (second laser light) incident on the first cladding, and a second fiber. The part of the nucleus (the third laser light). Therefore, the third laser light is incident on the second core from the first cladding layer, and further leaks to the outside through the second cladding layer. [3] In the above optical fiber, the NA of the second core may be larger than the NA of the first core. The NA referred to herein is equivalent to the NA of the fiber in a general SI fiber, and the maximum numerical aperture that cannot be enclosed in the core. In addition, in this specification, the above ΝΑ is sometimes referred to as "enclosed ΝΑ". According to this configuration, even if the second laser beam is "槪", even if the second laser beam is "second", the two cladding layers are appropriately reflected in the propagation of the lightning beam to appropriately suppress the output drop. ^ The first leap second, the fiber medium' may be the NA of the second fibril, and the difference of the first fibrils is 0 03 /, and the upper attack further suppresses the leakage of the third laser light to the outside. This kind of composition can

The first cladding layer: folding:: low also: the refractive index of the second cladding layer is set to be higher than the upper refractive index of the second: = species constitutes 'because the second cladding layer is appropriately larger than the first magnetic core like. ...low, so the NA of the second core can be made

[6J upper 逑 light shot, the thickness of the second cladding layer may be greater than the thickness of the first cladding layer of 201237478 l above. According to this configuration, since the thickness of the second layer is large, the NA of the (IV) first cladding i-core can be set as described above. Further, the shame of the core is appropriately larger than the thickness of the second cladding layer by the wear-through effect, and the NA is sealed even if it is qualitative. The same refractive index of the stomach can also be reduced. [7] In the above-mentioned optical fiber, the above-mentioned 笙 shape, the second _ can also be formed into a circular cross section! Compared with the above-mentioned first fiber #乐, the cut-off degree. The length of the child is 1.5 times to 1 inch, and the length of the second fiber (four) is set to be 1. 5 times to 1 G times longer than the first fiber. Therefore, the laser light can be used. The light body diameter right is 2nd _ ❸, and the average degree of exhaustion of the first laser light (the peak intensity of the light from the light _ laser light) can be set larger than the back shoulder threshold of the X piece. [8] The optical fiber may further include a third core that covers the second cladding layer and a third cladding layer that covers the third core, and the third core includes undoped quartz glass. The third cladding layer has a lower refractive index than the undoped quartz glass. According to such a configuration, for example, when a Gaussian-distributed laser light is incident on one end surface of the optical fiber, the center of the laser light can be propagated by using the first core; the second fiber can be used to propagate the laser light. A portion of the outer peripheral portion where the strength is relatively high can be transmitted by the third core to propagate a portion of the outer peripheral portion of the laser light having a relatively low intensity. Thereby, the intensity distribution of the laser light 8 201237478 ^ emitted from the optical fiber can be made close to the intensity distribution of the laser light in front of the person. Thereby, the deterioration of the intensity of the laser light in the domain (4) can be appropriately suppressed. [9] In the above optical fiber, the refractive index of the third cladding layer may be lower than the refractive index of the first cladding layer and the refractive index of the second cladding layer. According to this configuration, it is possible to appropriately suppress the leakage of the laser light emitted from the optical fiber (four) to the outside. '[10] The above-mentioned optical fiber may also have a single mode property. According to such a configuration, the peak intensity of the laser light emitted from the optical fiber can be improved as compared with the optical fiber having the multi-model property of the i-th core. Thereby, the peak intensity of the laser light can be made to be higher than the reaction 4 of the workpiece. [11] The laser processing apparatus of the present invention is characterized by comprising: a laser output portion for outputting a light, a fiber for propagating the laser light, and a laser emission for irradiating the laser light propagating through the optical fiber to the workpiece a; the above optical fiber is the optical fiber described above. According to the laser processing apparatus of the present invention, the same effects as those of the above optical fiber can be achieved. [12] The above-described laser processing apparatus may further include a laser incident portion that irradiates a laser beam output from the laser output unit to an end surface of the optical fiber, and the laser incident portion is the first The laser light is incident on the end surface of the optical fiber such that the diameter of the i-core is equal to or smaller than the outer diameter of the outermost core. According to such a configuration, the center portion of the laser light can be incident on the first core "and the outer peripheral portion of the laser light (the portion outside the center portion and within the range of the beam diameter) can be incident on the outermost core (the first 2 fiber core, 201237478 third fiber core). Thereby, it is possible to surely suppress the decrease in the output of the laser light, and it is possible to suppress the decrease in the peak intensity. [13] In the above laser processing apparatus, the laser incident portion may include a condensing lens that condenses laser light on an end surface of the optical fiber, and may change a face of the condensing lens and an end surface of the optical fiber. The position adjustment mechanism of the position. According to this configuration, since the positional adjustment mechanism can change the relative position of the condensing lens and the end surface of the optical fiber, the intensity ratio (energy balance, power) of the central portion and the outer peripheral portion of the laser light emitted from the optical fiber can be freely adjusted. balance). Thus, laser light having a suitable intensity distribution corresponding to the workpiece (object to be processed) can be easily obtained. As described above, according to the present invention, for example, when a Gaussian-distributed laser light is incident on an optical fiber, the center portion of the laser light can be propagated by the first core, and the laser beam can be propagated by the second core. The outer peripheral portion' thus reduces the output of the laser light and suppresses the decrease in peak intensity. Thus, in the case of processing a workpiece having a high reflectance using laser light of a fundamental wave, the peak intensity of the laser light on the workpiece can be made smaller than the reaction threshold without reducing the output of the laser light. The workpiece is processed stably. The above object and other objects, features and advantages will become more apparent from the following description of the preferred embodiments of the accompanying drawings. [Embodiment] Hereinafter, a preferred embodiment of the optical fiber of the present invention and a laser processing apparatus including the optical fiber will be described in detail with reference to FIG. (First Embodiment) First, the laser processing apparatus 10A of the first embodiment is configured as a so-called YAG laser processing apparatus, and is a device that propagates laser light having a wavelength by the optical fiber 12a and The laser light L1 is irradiated to the workpiece w, thereby being processed (cut, welded, etc.). Further, as the workpiece W, a metal material (steel, copper alloy, gold, or the like) having high reflectance (low absorption rate) of light in the infrared region can be arbitrarily selected. As shown in FIG. 1, the laser processing apparatus 1A includes a laser output unit 14 that outputs laser light L1 for processing, an optical fiber 12a that propagates the laser light L1, and an output from the laser output unit 14. The laser light 15 reflected in the predetermined direction by the laser light L1 is incident on the laser incident portion 18 of the one end surface of the optical fiber 12a, and the laser light L3 emitted from the other end surface of the optical fiber 12a is directed to the lens 15 a laser emitting unit 20 that irradiates a processing target portion of the workpiece w, a processing table 22 that positions and holds the workpiece W, and a control unit 24. The laser output portion 14 includes: a yag rod 26 including Nd:YAG crystal; an excitation lamp 28 for exciting an atomic light of the YAG rod 26; and a power source 3 for starting the excitation lamp 28; a cooling device 32 for cooling the YAG rod 26 and the excitation lamp 28, a total reflection mirror 34 disposed on one end side of the YAG rod 26, and a semi-transmissive property disposed on the other end side of the YAG rod 26. An output light-emitting mirror 36 is disposed between the total reflection mirror 34 and the output coupling mirror 36 so as to sandwich the YAG rod 26; 38. The configuration of the optical fiber 12a will be additionally described. The laser incident portion 18 includes a collecting lens 42 for collecting the laser light L1 incident on one end face of the optical fiber 12a. The laser emitting unit 20 includes a collimating lens 46 that aligns the laser light L3 emitted from the other end surface of the optical fiber 12a with the parallel light, and a clustering of the aligned laser light L3 at the processing target portion of the workpiece w. Light lens 48. The laser processing apparatus 10A of the present embodiment further includes a guided laser output unit 16' that outputs the guided laser light L2 as visible light so as to be coaxial with the laser light li. As the pilot laser output unit 16, for example, a He-Ne laser device or a GaA1PAs-based semiconductor laser device or the like is used. Thereby, the optical path of the laser light L1 which cannot be recognized by the naked eye can be easily obtained by guiding the laser light L2. As shown in FIG. 2 and FIG. 3, the optical fiber 12a is formed as a first core 5G which is formed on the axis Αχ, and is formed concentrically with the following portions: a first cladding layer 52, The second core 54, the second cladding 6, and the thick support layer 58. In other words, the first cladding layer 52 covers the outer peripheral surface of the first core 5〇, and the fibrils 54 cover the outer peripheral surface of the first cladding layer 52, respectively, and the second cladding layer is covered. The outer peripheral surface of the core 54 is covered with the outer periphery u of the second cladding layer. As shown in the drawing, the laser light incident on one end of the optical fiber 12a is in a position of 2, 5, and a Gaussian distribution. The width of the poly-t beam intensity P〇 of the beam intensity P3 of 18) is condensed by the above-described laser incident portion A side mirror 42' to be equal to or larger than the diameter d1 of the first core 50 and 201237478 second core 54 has an outer diameter d2 or less. Further, in the present embodiment, the size of the beam diameter d0 is the same as the outer diameter d2 of the second core 54. Thereby, the portion of the laser light having the beam intensity of P2 or more (the center portion of the laser light L1) is incident on the first core 50', and the portion having the beam intensity smaller than the above P2 and P1 or more is incident on the first package. The layer 52 has a portion having a beam intensity smaller than the above-described ρι and the above p 〇 or more is incident on the second core 54. In the following description, a portion of the laser light L1 incident on one end surface of the optical fiber 12a that is incident on the first core 50 may be referred to as a first laser light L1a, and a portion that enters the first cladding layer 52 may be incident on the first cladding layer 52. The portion referred to as the second laser light Lib, and the portion incident on the second core 54 is referred to as a third laser light (see FIGS. 2 and 5). Further, for convenience of explanation, the illustration of the third laser light L1 c is omitted in Fig. 5 . The first core 50 and the second core 54 include undoped quartz glass. Fine, this can be properly suppressed! The energy loss of the light Lla and the third laser light Lic. As shown in FIG. 2 and FIG. 3, the second core 54 is formed in a circular cross section, and the outer diameter d2 is set to be 15 times to 1 〇 = range, preferably 3, in comparison with the diameter d1 of the i-th core. The size of the double. In this manner, when the beam diameter dG of the money laser beam u and the outer diameter of the second core 54 are substantially equal to each other, the first laser light L1 can be made to have an average intensity response threshold value PL·. 13 201237478 Reduce the amount of the second laser light Lib. Thereby, the energy loss of the laser light L1 incident on the optical fiber can be suppressed. The first cladding layer 52 and the second cladding layer 56 are formed by doping gas into quartz glass. Further, the amount of gas per unit mass of the second cladding layer 56 is larger than the amount of fluorine per unit mass of the first cladding layer 52. The refractive index n2 of the cladding layer 52 is lower than the refractive index of the i-th core % and the second == quartz glass, and the second cladding layer = the transmittance 111 is lower than the refractive index n2 of the first cladding layer 52. As a result, the enclosed NA of the 2nd = 54 is larger than the enclosed NA of the 1st core 5〇. And the core, as shown in Figure 5, has been incident on

When Ub is incident on the second core 54, it can be leaked to the outside by the 2 packs of /: 丄~, the dotted line L〇 in Fig. 5). ^

The doping amount may be: =, = the amount of the impurity and the gas in the second cladding layer 56. For example, the difference between the enclosed enthalpy of the second core 54 and the enclosed NA = 50 may be set to 0.03 to 〇.15. _ ;; 1st advance-step suppression of the leakage of the second laser light Llb to the outside of the 'widehand': 1 2 and the second cladding 56 can also be rolled in quartz glass (bf3) or Boron oxide (Β 〇), a composition of this type, can also make the first. Even for

The refractive index η2 of the projection cladding layer and the second cladding 子Q ratio η3 are lower than the refractive index of the undoped quartz glass. The support layer 58 and the unsupported quartz glass monolith support layer 58 The thickness can be appropriately shot/18 or force according to the size of a connector or the like connected to the lightning-emitting laser emitting unit 20, and the refractive index n3 of the layer 28 of the 201237478 layer 58 and the first and second cores and the second core can be supported. The prayer control unit 24 includes the first control unit 60 that controls the power supply 3〇 of the laser output unit ,, and the second control that controls the laser output unit 16 to drive the drive. Further, the control unit 24 drives the opening and closing of the gears 38, and drives and controls the cooling device 32. In the laser processing device 10A configured as described above, first The shackle 24 opens the shutters 38, 38, and then the second control unit 62 drives the guide 铯 屮 A , , , 4 射 射 射 4 4 4 4 4 4 4 输出 输出 输出 输出 输出 输出 输出 输出 输出 输出 输出Lens, laser incident portion 18, optical fiber 12a, laser emitting portion 20, and processing station 22

= position adjustment. At the stage where the position adjustment is completed, the second control unit 62 stops the driving of the guide bow laser output unit 16. Then, the first control unit 60 drives the power source 30 to cause the laser to be "flashed". Thereby, the reversely distributed light is excited from the laser active medium in the third rod 26. The light is resonantly amplified between the total reflection mirror 34 and the input mirror 36%, and the amplified light is output as the laser light L1 through the output coupling mirror dream 2. In addition, at this time, the first control unit 6〇

The device 32 is driven to cool the YAG rod 26 and the excitation lamp 28. X is reflected by the laser light output from the laser output unit 14 to the lens 15 and the fiber 12 is bowed to the laser incident portion 18, and is condensed by the condensing lens 42 to the end face of the light source. Specifically, the laser light L1 is incident on one end surface of the optical fiber 12a so that its optical axis substantially coincides with the axis Αχ of the optical fiber first core 50). In the above, the laser light L1 is divided into the first laser light L1a incident on the first core 50, the second laser light Lib incident on the first cladding layer 52, and the third laser light Lie incident on the second core 54. . That is, the first laser light Lla propagates in the first core 50, and the second laser light Lib and the third laser light Lie propagate in the second core 54. Further, the first to third laser lights L1a to Lie emitted from the optical fiber i2a are combined to become the laser light L3. As shown in Fig. 4B, in the laser light L3, the average intensity of the first laser light Ua is expressed as the peak beam intensity P5, and the average intensity of the second laser light Lib and the third laser light Lie is expressed as the beam intensity p4. As a result, the peak intensity P5 of the laser light L3 is sufficiently increased as compared with the reaction threshold pL of the workpiece. Then, the above-described laser light L3 is parallelized by the collimator lens 46, and then condensed by the condensing lens 48 to the processing target portion of the workpiece w. Thereby, the laser center portion having the beam intensity P5 serves as a processing target for the processing target position of the workpiece w, and the processing can be performed (expanded) on the laser outer circumference having the beam intensity H. Therefore, it is possible to stably use the long laser light L1 with the long laser light L1 (the first modification) (the second modification), and the above-described fiber 仏 shape will be described with reference to FIG. In the following description, the configuration of the above-described embodiment is the same as the second modification and the third modification, which will be described later. In the optical fiber (3), the second cladding layer 64 is used instead of the second cladding layer 56 and the support layer 58 constituting the light 16 201237478 r 12a. That is, in the present modification, the support layer 58 of the optical fiber 12a is omitted, and The thickness of the second cladding layer 64 is set to be larger than the thickness of the second cladding layer 56. The doping amount per unit mass of fluorine in the second cladding layer 64 and the doping amount per unit mass of fluorine in the second cladding layer 56. The amount is the same, and is set to be larger than the doping amount per unit mass of fluorine in the first cladding layer 52. In this case, the bending rate of the second cladding layer 64 is set to n, and the light is worn according to the modification. The same effect as the above-described optical fiber 12a can be achieved. (Second Modification) Next, the optical fiber of the second modification will be described with reference to Figs. 7 and 8 12c. As shown in Fig. 7 and Fig. 8, in the optical fiber of the present modification, the second cladding layer is used instead of the second cladding layer 56 constituting the optical fiber 12a. Specifically, the thickness of the second cladding layer 66 is formed. It is larger than the thickness of the i-th cladding layer & The doping amount per unit mass of fluorine in the second cladding layer 66 is set to be the same as the amount of __ per unit mass in the second cladding layer 52. In this case, 2 The refractive index n2 of the cladding layer 66 and the second cladding layer 52 may of course be the same as the above-mentioned optical fiber bundle, and each of the doping amounts per unit mass of fluorine in the second cladding layer 66 is _ The amount of doping may be large. According to the optical fiber 12c of the present modification, since the thickness of the J 1 cladding layer 52 is large, the same effect can be obtained for the second core 5: The money and the above-mentioned optical fiber i2a 17 201237478 The difference between the thickness of the first cladding layer 52 and the thickness of the second cladding layer 66 is arbitrarily set. For example, the difference between the sealed NA of the second core 54 and the sealed NA of the second core 5〇 can be set to 〇 〇3 to 〇15. In this case, it is possible to further suppress leakage of the second laser light Lib to the outside. In the example of this example, the optical fiber (10) of the above-described modification can be used. The support layer % is omitted, and the thickness of the second cladding layer 66 is increased by the amount (four) of the thickness of the support layer 58. Even in this case, the same effect is obtained. 'C third modification example _ 12 ^1 The optical fiber 12d of the third modification will be described with reference to Figs. 9 to UB. As shown in Fig. 9, as shown in Fig. 10, the third core 68 on the outer peripheral surface of the fiber skein cladding 56 of the present modification is smashed into the third cladding 70 on the outer peripheral surface of the third core 68. In other words, the optical fiber 12d is provided with the following portions to form the f-fiber 5G with respect to the flute, and is concentrically shaped. The third cladding layer 70 and the bridging layer 58. Further, the outer peripheral surface of the support layer 5_the third cladding 7Q. As shown in FIG. 11A, the incident lens U is generally Gaussian, and the laser beam intensity P3 of the laser light level P0 in front of one end of the fiber is concentrated by the concentrating lens 42 of the beam intensity P3. The diameter of the core 68 of the shot portion 18 is equal to or smaller than d3. In addition, in the present modification, the beam is straight: this =? The outer diameter of the I core 68 is the same size. a portion 201237478 r (the center portion of the laser light L1) having a beam intensity of P2 or more is incident on the first core 50, and a portion having a peak intensity smaller than the above P2 and having a peak intensity of P1 or more is incident on the first cladding layer 52, and has a smaller value than the above. A portion of the beam intensity of P1 and Pb or more is incident on the second core 54, and a portion having a beam intensity smaller than the above Pb and Pa is incident on the second cladding 56, and has a partial incidence of a beam intensity smaller than the above Pa and P0 or more. In the following description, a portion of the laser light L1 incident on one end surface of the optical fiber 12d and incident on the second cladding layer 56 may be referred to as a fourth laser light Lid, and may be incident on the first. The portion of the 3 core 68 is referred to as a fifth laser light Lie. The third core 68 is formed in a circular cross section, and the outer diameter d3 is set to be 1.5 to 10 times larger than the diameter d1 of the first core. , preferably 3 times the size. The setting is made in this way because the beam diameter d0 of the laser light L1 is made When the outer diameters of the three cores 68 are substantially the same, the average intensity of the first laser light L1a can be made larger than the reaction threshold value PL of the workpiece W. The third core 68 includes the same as the first core 50 and the second core 54. The undoped quartz glass can thereby appropriately suppress the energy loss of the fifth laser light Lie. The third cladding layer 70 is formed in a circular cross section and has a thickness equal to that of the first cladding layer 52 and the second cladding layer 56. The thickness of the third cladding layer 70 is doped with fluorine in the quartz glass. Moreover, the doping amount per unit mass of fluorine in the third cladding layer 70 is higher than that per unit mass of fluorine in the second cladding layer 56. Therefore, the bending rate n0 of the third cladding layer 70 is lower than the bending rate n1 of the second cladding layer 56, and as a result, the encapsulation NA of the third core 68 becomes larger than the encapsulation NA of the second core 54. 19 201237478 Thereby, the first to third cores 68 that have entered the second cladding layer 56 are incident on the third cladding beam Ud, and the fourth laser beam Ld can be suppressed from being reflected by the third laser beam Lld. The doping amount of the fluorine doping amount of the fluorine in the second cladding layer 56 to the outside may be arbitrarily set, for example, the third fiber core: 1 of the layer 7 的The difference of the sealed NA of the core = can be set to be ~10)^^ 2 The leakage of the fourth laser light Lld to the outside can be further suppressed. In addition, the 'the third cladding 70 can also be doped with trifluorosulfate in the quartz glass ( BF3) or boron oxide (B2〇3). Even in such a configuration, the bending rate n〇 of the third cladding layer 70 can be made lower than the undoped quartz glass ratio nl. According to the present modification, the laser light is used. L1 is divided into: the first laser light Lb' incident on the first cladding layer 5a incident on the first cladding layer 52, and the third laser light Lie incident on the second core 54 to enter the first laser light The fourth laser light Lid of the second cladding layer 56 is incident on the fifth laser light Lie of the third core 68. That is, the 'first laser light LI a propagates in the first core 50, the second laser light Lib and the third laser light Lie propagate in the second core 54, and the fourth laser light Lid and the fifth laser light Lie are in the first 3 fiber core 68 spread. Further, the i-th to fifth-th laser light Lla to [e.g., which is emitted from the optical fiber 12d, is combined into the laser light L3. σ As shown in FIG. 11A, in the laser light L3, the i-th laser light B. The average intensity is expressed as the peak beam intensity P5, and the average intensity of the second laser light Llb 201237478 f and the third laser light Lie is expressed as the beam intensity, and the average intensity of the fourth laser light Lid and the fifth laser light Lle is used as the light beam. The intensity Pc is expressed. Therefore, the intensity distribution of the laser light L3 obtained by the propagation of the optical fiber 12d in the present modification (see FIG. 11B) is higher than the intensity distribution of the laser light L3 obtained by the above-described propagation of the optical fiber (see FIG. 4B). The intensity distribution of the light U is received. In other words, by reducing the optical fiber 12d of the financial modification, the intensity of the laser light li propagating in the light or the fiber (3) can be appropriately suppressed (deterioration of quality). (Fourth Modification) Next, an optical fiber 12e according to a fourth modification will be described with reference to Fig. 12 . In the modification, the constituent elements of the third modification described above are denoted by the same reference numerals, and the detailed description thereof will be omitted. The same applies to the fifth modification and the sixth modification described later. As shown in FIG. 12, in the optical fiber 12e of the present modification, the fluorine per unit mass of the second cladding layer/the second cladding layer 72 is used instead of the second cladding layer 56 constituting the optical fiber (3) of the third modification example. The amount is set to be the same as the doping amount per unit mass of fluorine in the second cladding layer 52, and the other configuration is the same as the second item. Thereby, the refractive index of the second cladding layer 72 becomes n2 which is the same as the refractive index of the i-th cladding layer 52. In the example of ==, since the refractive index n〇 of the third cladding layer 7〇 is lower than the curvatures of the fth layers of the i-th cladding layer 52 and the “cladding layer 72”, it is possible to appropriately suppress the transmission of the divination 5 _ Lla 〜 Ue The third cladding layer is leaked out. According to the optical fiber 12e of the present modification, the same effect as the optical fiber (3) can be achieved. 21 201237478 (Fifth Modification) Next, the '-surface is referred to FIG. The optical fiber 12f is δ. As shown in Fig. 13, the optical fiber 12f of the present modification is deformed, and the optical fiber is called a target, instead of the third cladding 7=_1: ^ the third cladding 74. That is, the present modification In the example, the thickness of the third cladding layer 74 is set to be larger than the thickness of the third cladding layer 7〇. The replacement of I per unit mass in the 7n + Λ layer % The doping amount (IV) of the amount of fluorine relative to the mother early mass of the third cladding layer is set to be larger than the doping amount of fluorine in the second cladding. The precursor fiber 12f' in the present modification can be realized with the above optical fiber. The same effect is obtained. (Sixth Modification) Optical fiber t irradiation 2 4 and FIG. 15 - Optical fiber 12g facing the sixth modification and third modification FIG. 15, the second sentence is used in the present modification; In contrast to the second cladding 56 In the second sentence, the third cladding layer 70 is used, and the third cladding sound 78 is used. The thickness of the second cladding layer 66 is formed. # Using the third layer of the slider 3, the third cladding layer 78 is formed to have a larger thickness than the first cladding layer 52. In the layer & 66, 78, the thickness of the ^ cladding layer 66 is large. In this case, the amount of fluorine of each #早立贝量 is set to be the same. According to the refraction of 4 =:, 78 The rate is also the same as that of the first cladding layer 52, 12g', the thickness of the second cladding layer 66 is set to be 5 degrees larger than that of the second cladding layer 66, and the thickness of the third cladding layer 78 is set.

The ratio of ::8 to the first fibrid 5 因而 makes the encapsulation NA of the second core 54 into NA larger than the encapsulation of the third core 64 of the second core 54 to NA. Optical fiber 22 according to the present modification, 201237478,

Ug can achieve the same effect as the above-mentioned optical fiber i2d. Further, of course, the doping amount per unit mass of the third cladding layer 78 is set to be larger than the doping amount per unit mass of fluorine in the second cladding layer 66. The present embodiment is not limited to the above configuration. For example, instead of the bamboo lamp 28, a laser diode (LD) can be used to excite the rod 26. Further, the laser processing apparatus 1A of the present embodiment can be constructed as a YAG laser welding machine. Further, the optical fiber 12a to the optical fiber 12g may be configured to have a single mode. Such an optical fiber 12a to an optical fiber 12g can be formed, for example, by forming a large size of 8 [μιη]~ι〇(4), and obtaining a multi-model by the configuration of the i-th core 5〇. The optical fiber phase can improve the wave bee intensity p5 of the laser light L3. Thereby, the peak intensity p5 of each of the light beams L3 can be surely made higher than the reaction threshold of the workpiece. The shape of the circular two-fiber can also be a polygonal shape of a section and an elliptical shape of a section. Further, the i-th cladding layer 52, the second cores 5, 4, 66, 72, the third core 68, and the third cladding layer 7. 2, 72 = 8. Each of the cross-sectional shapes may be a polygonal cross section and a cross section (second embodiment). The second embodiment of the present invention will be described. In the present embodiment, the same reference numeral 23 201237478. is attached to the above-described first constituent element__ element, and a detailed description thereof will be omitted. The same applies to the third embodiment to be described later. As shown in FIG. 16, the laser processing apparatus 10B is configured as a so-called optical fiber laser processing apparatus, and the laser output unit 100 is used instead of the laser output unit 14, and the control unit 102 is used instead of the control unit 24, and the guidance is omitted. The laser output unit 16 is led. The laser output unit 1 is a member for outputting the fiber laser light FBI having a wavelength of 1..064 [μηι], and includes a power source 1〇4, which is driven by the excitation current from the power source 104 and is outputted with excitation. a laser diode (LD) 106' of light mb oscillates an optical fiber (active fiber) 1 〇 8 for oscillating the optical fiber laser light FBI by propagating the above-described excitation light MB, via the above-mentioned active optical fiber A pair of optical resonator mirrors 110 and 112 that are optically opposed to each other are disposed on one end surface of the active optical fiber 108 and the optical lens 114 between the optical resonator mirrors 11 The optical lens 116 between the other end surface of the active optical fiber 1 8 and the optical resonator mirror 112. Although the active optical fiber 108 is not shown in detail, it includes a core doped with a predetermined light-emitting element and a cladding that coaxially surrounds the core, and the core is used as an active medium, and the cladding is used as excitation light MB. The propagation optical path Y "--amplifies the energy of the optical fiber laser FBI oscillated from the active optical fiber 108 by the optical resonator mirrors 110, 112. The optical resonator mirror (10) transmits excitation from the LD1 〇 6 from the back side of the reflective surface. The light MB' and the fiber laser light FB1 guided from one end face of the active fiber 108 are totally reflected along its optical axis. The optical resonator mirror 112 will guide the fiber from the other end face of the active fiber 108 to the 24,037,478 r optical fiber. The laser FBI is partially reflected along its optical axis to transmit a part of the fiber laser light FBI. The optical lens 114 condenses the above-mentioned fiber laser light FBI reflected by the optical resonator mirror 11 and the above-mentioned excitation light MB from the LD 106 to the active fiber. One end face of 108, on the other hand, parallelizes the fiber laser light FB1 guided from the = end face of the active fiber 1 〇 8. The optical lens 116 condenses the above-mentioned fiber laser light FB1 reflected by the optical resonator mirror 112 The other end face of the active optical fiber 108, on the other hand, parallelizes the optical fiber laser light FB guided from the other end surface of the active optical fiber 1 8 . Further, the control unit 102 drives and controls the power supply 1 〇 4 In the present embodiment, when the control unit 102 drives and controls the power source 1〇4 and supplies an excitation current from the side power source 104 to the LD 106, the excitation light MB that oscillates the excitation light MB' from the LD1〇6 is transmitted through the optical resonator mirror. The illuminating light is incident on the end face of the active optical fiber 108 by the optical lens 114, and the excitation light MB of the active optical fiber 108 is incident on the fiber surface of the active optical fiber 1 〇 8 The cross-cut surface propagates in the cladding to excite the luminescent element in the core. Thus, the optical fiber laser light FBI is emitted from the active optical fiber 1〇8, and is amplified by a pair of optical resonator mirrors 11〇, 112, and transmitted through the light. The resonator mirror 112 is guided to the lens μ. The fiber laser light FBI emitted from the laser output unit 1〇0 is reflected by the lens 15 in the same manner as in the first embodiment, and is condensed by the laser incident portion 18. 42 and a concentrated light is incident on one of the optical fibers 12a for propagation The end face of the optical fiber laser light FB1 having a substantially Gaussian distribution incident on the optical fiber 12a is separated by the first core 5〇 and the second core % of the optical fiber 12a. Thereby, 25 201237478 does not make the optical fiber laser FBI The output is lowered, and the fiber laser light FB2 having a peak intensity sufficiently higher than the reaction threshold PL of the workpiece W is emitted from the other end surface of the optical fiber, and is condensed on the processing target portion of the workpiece w via the laser emitting portion 20. 'The optical fiber laser light FB 2 having a wavelength of 1.〇64 [μιη] can be used to stably process the workpiece W having a high reflectance of light in the infrared region. As described above, in the laser processing apparatus 10 of the present embodiment, the same effects as those of the laser processing apparatus 1 of the first embodiment described above can be achieved. The present embodiment is not limited to the above configuration. For example, the laser processing apparatus 10A of the present embodiment can also be configured as a laser processing apparatus (laser welding machine) including an active optical fiber 108 having a plurality of modeling properties. Further, in the present embodiment, the optical fiber 12b to the optical fiber 12g may be used instead of the optical fiber 12a. Further, each of the optical fibers i2a to 12g may be configured such that the first core 50 has a single mode property. Such an optical fiber 12a to 12g can be obtained, for example, by setting the diameter of the first core 50 to a size of 8 μm to 1 μm. In this case, the laser output unit (10) may be configured such that the quality of the fiber laser light FBI is Μ2=2. Thereby, the peak intensity Ρ5 of the laser light L3 can be improved as compared with the fiber having the multi-model property of the first core 50. Thereby, the peak intensity Ρ5 of the laser light L3 can be surely made higher than the reaction threshold hole of the workpiece w. Further, in the present embodiment, the excitation light MB emitted from the LD 160 is incident on the active optical fiber (10), and the laser light FB1 amplified by the optical resonator mirror ιι〇2 is incident on the optical fiber 12a. On the other hand, it can be configured as follows (so-called LD direct processing device): it is not necessary to use the active 26 201237478 r-type optical fiber, optical resonator mirror, m, etc., and the direct excitation light MB is directly incident on the optical fiber 12a (12b). ~12g). (Embodiment 3) Next, a laser processing apparatus 1GC according to the first aspect of the present invention will be described with reference to Figs. 17 to 24 . As shown in Fig. 17, the laser processing of the present embodiment is set as a YAG laser splicer, and a laser incident portion 2 is provided instead of the laser incident portion 18. The laser incident portion 200 includes a position adjustment mechanism 201 for adjusting the position of the end face of the condenser lens 42 and the optical fiber bundle. The position adjustment mechanism 201 includes a lens holder 202 for supporting the condensing lens 42, and a fiber holder 2 〇 4 for supporting the one end side of the optical fiber 12a # (the side close to the condensing lens 42). As shown in FIG. 18, the lens holder 2〇2 includes a holder body 206 in which the condensing lens 42 is held, and a support portion 2〇8 that can support the holder body 2〇6 in the optical axis direction of the laser beam u. And a position adjusting screw 210 for the bracket body to move in the optical axis direction of the laser beam u and a rod 212 fixed to the support portion 208. As shown in FIG. 19, the fiber holder 204 includes a holder body 214 that holds one end side of the optical fiber 12& and the holder body 214 can be oriented along the optical axis of the laser light u (with the central axis Ax of the optical fiber 12a). a support portion 216 that is movably supported, a screw 218, 220 that is provided in the support portion 216 and that moves the bracket body 214 in a direction orthogonal to the optical axis of the laser light L1 And a rod 222 fixed to the support portion 216. 27 201237478 According to the fiber holder 204 thus constructed, the holder body 214 can be moved relative to the support portion 216 along the extending direction of the rod 222 by rotating the position adjusting screw 218 ′, and the holder can be rotated by rotating the position adjusting screw 22 〇 The body 214 moves relative to the support portion 216 in a direction orthogonal to the direction in which the rods 222 extend. In the present embodiment, the holder main body 206 can be moved along the optical axis of the laser beam u by rotating the position adjusting screw 210 of the lens holder 2〇2. Thus, the end surface (incident side end surface) and the condensing light of the optical fiber 12a can be changed. The distance of the lens 42 (the focus position of the laser light L1). Specifically, for example, the bracket body 206 is disposed at the position shown in Fig. 18, and the two-point chain line Ai of the intensity distribution of the laser light u before the optical fiber 12a is incident. Further, the intensity distribution from the optical fiber i2a "' becomes the two-point chain line A2 shown in Fig. 21B. For the high-I and the second, the peak intensity of the center portion is maintained to be low for the workpiece|_chemical balance. Such laser light L3 is narrowed, so that, for example, the width of the molten portion 300 (see Fig. 22) can be obtained. In the σ field, lap welding of the thick plates 302 and 304, etc. (the position adjustment snail of the rotating lens holder 202 is shown in Fig. 20), and the person shoots; ^ moves toward the end face side of the fiber ( (see Therefore, the intensity of the _L1 before the actual 仏L1 is distributed as the energy of the laser light L1. Thus, the energy of the laser beam L1 incident on the first core 50' and incident on the second core 54 201237478 Therefore, the intensity distribution of the laser light u emitted from the optical fiber 12a becomes the solid line B2 shown in Fig. 21B. That is, in the laser light L3, the peak intensity at the center portion thereof is relatively low, and the outer peripheral portion thereof is The above-described laser beam S L3 is relatively shallow in melting of the workpiece w and the width (diameter) of the molten portion 3〇6 is widened. Therefore, for example, lap welding of the thin plates 3〇8 and 31〇 can be performed appropriately. As described above, in the present embodiment, the position adjusting screw 210 of the lens holder 202 is rotated to cause the holder main body to move in the optical axis direction of the laser light L1, thereby changing the focus position of the collecting lens 42, so that the focus position of the collecting lens 42 is changed. The central portion and the outer portion of the laser light L3 emitted from the optical fiber Ha can be freely adjusted The intensity ratio (quantity balance, power tilt) of the part. In this way, it is possible to have a suitable intensity of laser light L3 corresponding to the welding conditions (fastening conditions) such as the thickness of the workpiece 。. When the position adjusting screw 22 of the optical fiber holder 204 is rotated to move the holder main body 214 in a direction orthogonal to the optical axis of the laser light L1 (a direction orthogonal to the extending direction of the disk bar 222), the laser light incident on the front side of the optical fiber is irradiated. The intensity distribution of L1 is such that the solid line 所示 shown in Fig. μ is reduced. Thus, the amount of laser red 丨 _ of the first meaning 5Q is reduced, and the energy of the laser light L1 incident on the second core 54 is increased. The intensity distribution of the laser light L3 emitted from the optical fiber 12a becomes the solid line C2 shown in Fig. 2ib. Thus, the holder body 214 of the optical fiber holder 204 is moved even without moving the holder body 2〇6 of the lens holder 202. In this case, the intensity ratio (energy balance, 29 i i201237478 power balance) between the center portion and the outer peripheral portion of the laser light L3 can be adjusted freely. Thereby, the welding condition (hardening condition) with the workpiece ~ can be easily obtained. corresponding The laser beam of a suitable intensity distribution is not limited to the above configuration. For example, the position 2〇1 may be configured such that the holder body of the lens holder is moved or the holder body 214 of the fiber holder cannot be moved, & Moreover, the lens holder 202 can be configured such that the holder body 2〇6 can move in a direction orthogonal to the optical axis of the laser light L1, and the fiber holder 2〇4 is configured such that the holder body 214 can be along the mine The optical axis of the illuminating light L1 is shifted by . In addition, the mechanism for moving the bracket bodies 206 and 214 can utilize the motor as a whole, and the position adjusting mechanism 211 can change the relative position of the condensing lens 42 and one end surface of the optical fiber 12a. Then how to construct it. Further, for example, the laser processing apparatus 10c of the present embodiment can use the above-described optical fibers i2b to 12g instead of the optical fiber 12a. Further, the laser processing apparatus 10C of the present embodiment can also be used for welding a foil material (aluminum foil, copper foil, or the like) constituting an electrode of a clock ion battery. In this case, the relative position of the end face of the condensing lens 42 and the optical fibers 12a (12b to 12g) can be adjusted, and the peak intensity of the laser light L3 emitted from the optical fibers 12a (12b to 12g) can be reduced, whereby the angle can be appropriately suppressed. The foil is damaged by the laser light L3. Further, the positional deviation of the foil when the laser light L3 is irradiated onto the foil can be suppressed. The present invention is not limited to the above embodiments, and various configurations can of course be employed without departing from the gist of the invention. For example, the optical fiber of the present invention may be configured such that a plurality of cores and cladding layers are alternately arranged concentrically (for example, four layers are used on 30 201237478 f). In this case, the intensity distribution of the laser light emitted from the optical fiber can be made closer to the intensity distribution of the laser light incident on the optical fiber. Thereby, deterioration of the quality of the laser light by the optical fiber can be appropriately suppressed. In this case, it is preferable to set the refractive index of the outermost cladding layer to be smaller than the refractive index of the other cladding layers. In this way, the encapsulation NA of the outermost core can be set to be larger than the encapsulation NA of the other core, and as a result, leakage of the laser light incident on the optical fiber to the outside can be appropriately suppressed. The laser processing apparatus of the present invention can also be applied to a welding apparatus (copper strip line welding apparatus) for welding a copper tape (c〇pp〇er ribbon). In this case: 'A laser beam having a wavelength of l.G64 [_ is used to stably weld the copper strip to the reflectance. [Simple description of the map], 1 is the first! A block diagram of the main part of the laser-assisted device of the embodiment. Fig. 2 is a longitudinal sectional view, partly omitted, of the one end side of the optical fiber shown in Fig. 1. 3 is an explanatory view showing a cross-sectional view taken along line m_m of FIG. 2 and a refractive index distribution of the optical fiber shown in FIG. 2. The sound of the laser light is not incident on the intensity of the laser light before the optical fiber shown in Fig. 2; Fig. 4' is an explanatory view showing the intensity distribution of the laser light emitted from the optical fiber. ^ ^ The enlarged cross-sectional view of the portion of the button shown in Fig. 2 is omitted. The cross-sectional view of the optical fiber of the first modification and the explanatory diagram of the refractive index distribution of the optical fiber are shown. 201237478 Fig. 8 is a longitudinal 咅 of a portion of the optical fiber in which the second modification is omitted. Fig. 8 is an explanatory view showing a refractive index distribution of an optical fiber which is not shown along the line VIII-Vin of Fig. 7. Fig. 9 is a longitudinal cross-sectional view of the optical fiber of the third modified example. Fig. 1A is an explanatory view showing a refractive index distribution of the optical fiber of the cross-sectional view of Fig. 9 along the Χ-Χ line. . Fig. 11A is an explanatory view showing a distribution of a gradient before entering the optical fiber shown in Fig. 9, and Fig. 11 is an explanatory view showing a strong intensity distribution of light emitted from the optical fiber. Fig. 12 is an explanatory view showing a refractive index distribution in a transverse cross section of an optical fiber according to a fourth modification. Fig. 13 is an explanatory view showing a refractive index distribution in a transverse cross section of an optical fiber according to a fifth modification. Fig. 14 is a longitudinal cross-sectional view of a portion of the optical fiber in the sixth modification. Fig. 15 is an explanatory view showing a refractive index distribution of the optical fiber in the cross-sectional view taken along line XV-XV and Fig. of the drawing. One solid 14 Fig. 16 is a block diagram showing a laser processing dress & Main part Fig. 方块 is a block diagram showing the laser processing apparatus of the third embodiment. Main portion of the housing Fig. 18 is a side elevational view of the position adjusting mechanism shown in Fig. 17. . Fig. 19 is an enlarged front elevational view of the fiber holder shown in Fig. 18. 32 201237478. Fig. 20 is a partially enlarged cross-sectional side view showing a state in which the holder main body constituting the lens holder is moved toward the one end surface side of the optical fiber. FIG. 21B is an explanatory view showing the intensity distribution of the laser light before and after the movement of the optical fiber before and after the movement of the holder main body constituting the lens holder, and FIG. 21b is an indication of the intensity of the optical fiber before and after the movement of the holder main body constituting the lens holder. An illustration of the distribution. $ 圃U疋 is used in the description of the (4) part of the (4) part of the danwei diagram 2 in the case of glazing by the dotted line 8 2 intensity distribution (4). knock. Fig. 23 is a cross-sectional explanatory view for explaining melting in the case of lap welding by laser light having the intensity distribution shown by the solid line in Fig. 21B. . Movement of the body of the shape of the crucible Fig. 24 is an explanatory view showing the intensity distribution of the laser light before and after the fiber incident on the front and rear sides of the holder constituting the fiber holder. [Description of main component symbols] 10A to 10C: laser processing devices 12a to 12g: optical fibers 14, 100: laser output portions 18, 200. laser incident portion 20: laser emitting portions 24, 82: control portion 5 : 1st core 52 : 1st cladding 54 : 2nd core 33 201237478^ 56, 64, 66, 72: 2nd cladding 58: Support layer 68: 3rd core 70, 74, 78: 3rd Cladding 201: Position adjustment mechanism 202: lens holder 204: fiber holder LI, L3: laser light FBI, FB2: fiber laser light 34

Claims (1)

201237478" VII. Patent Application Range: 1. An optical fiber for propagating laser light, comprising: a first core (50); a first cladding (52) covering the first core (50) a second core (54) covering the first cladding layer (52); and a second cladding layer (56, 64, 66, 72) covering the second core (54); The 1 core (50) and the second core (54) comprise undoped quartz glass, and the first cladding layer (52) and the second cladding layer (56, 64, 66, 72) have a refractive index lower than a refractive index of the undoped quartz glass. 2. The optical fiber of claim 1, wherein the first cladding layer (52) and the second cladding layer (56, 64, 66, 72) are formed by doping fluorine into quartz glass. . 3. The optical fiber according to claim 1, wherein the NA of the second core (54) is larger than the NA of the first core (50). 4. The optical fiber according to claim 3, wherein a difference between the NA of the second core (54) and the NA of the first core (50) is 0.03 to 0.15. 5. The optical fiber of claim 3, wherein the second cladding (56, 64) has a lower refractive index than the first cladding (52). 6. The optical fiber of claim 3, wherein the thickness of the second cladding layer (64, 66) of 35 201237478 A 1 is greater than the thickness of the first cladding layer (52). 7. The optical fiber according to claim 1, wherein the first core (50) is formed in a circular cross section; and the second core (54) is formed in a circular cross section; The outer diameter of the core (54) is 1.5 to 10 times the diameter of the first core (50). 8. The optical fiber of claim 1, further comprising: a third core (68) covering the second cladding (56, 64, 66, 72); a third cladding (70, 74) 78) covering the third core (68); and the third core (68) comprises undoped quartz glass, and the third cladding (70, 74, 78) has Undoped quartz glass has a low refractive index. 9. The optical fiber of claim 8, wherein the third cladding layer (70, 74) has a refractive index that is greater than a refractive index of the first cladding layer (52) and the second cladding layer ( The refractive indices of 56, 64, 66, and 72) are low. The optical fiber according to any one of claims 1 to 9, wherein the first core (52) has a single mode property. 11. A laser processing apparatus, comprising: a laser output portion (14, 100) for outputting laser light; an optical fiber for propagating the laser light; and 36 201237478 〆 laser emission portion (20) by The laser light propagated by the optical fiber is irradiated to the workpiece (W); and the optical fiber is the optical fiber (12a to 12g) according to any one of the first to tenth aspects of the patent application. 12. The laser processing apparatus of claim 5, further comprising a laser incident portion (18, 200) from which the laser exit portion (18, 200) will be taken (14) , the output laser light is incident on an end surface of the optical fiber (12a to 12g); the laser incident portion (18, 200) is directly controlled by the beam of the laser light as the first magnetic core The laser light is incident on the end faces of the optical fibers (12a to 12g) such that the diameter of (5 〇) is equal to or larger than the outer diameter of the outermost core. The laser processing apparatus according to claim 11, wherein the laser incident portion (200) comprises: a collecting lens (42) for concentrating laser light on the optical fiber (12a to 12g) The end surface and the position adjustment mechanism (2〇1) can change the relative positions of the condensing lens (42) and the end faces of the optical fibers (12a to 12g). 37