WO2004010194A1 - Optical device and method of assembling the device - Google Patents

Abstract

An optical device and a method of assembling the device, the device comprising a substrate (5) and a lens (Ls) installed on the substrate (5); the method comprising the steps of sticking a holder (51) onto the substrate (5) with UV adhesive agent (52) and fixedly sticking the lens (Ls) onto the holder (51) with the UV adhesive agent (53), the lens (Ls) is held by a holder (57) fitted to the tip of the arm (56) of an adjusting jig (55), adjusting the position of the lens (Ls), and radiating ultraviolet ray to the UV adhesive agent (53) to cure the UV adhesive agent to fixedly adhere the lens (Ls) at a desired position, whereby optical elements can be easily fixed onto the substrate in proximity to each other, and the size of the device can be easily reduced.

Description

 Itoda optical device and its assembling method

Technical field

 The present invention relates to an optical device having an optical element fixed at a predetermined position on a substrate (base) and a method for assembling the optical device. Background art

 Various optical devices, such as lasers and measuring instruments, are configured by positioning optical elements such as lenses on a substrate and mounting them. However, accurate positioning is required when mounting optical elements on a substrate. For this reason, the optical element is mounted on the substrate so that the positioning can be adjusted, an example of which is shown in FIG. In this example, a fixed holder 101 is fixed on a metal substrate 100 with screws 102, and a lens holder 1 1 1 holding a lens 110 is fixed to the fixed holder 101. The pillars 1 1 and 2 are fitted and attached, and the fitted state is fixed with screws (not shown). The position of the fixed holder 101 can be adjusted in the horizontal direction by loosening the fastening with the screw 102, and the position of the lens holder 111 can be adjusted in the vertical direction by adjusting the fitting position of the column 111. is there.

 Also, as shown in FIG. 16, a fixed holder 1 25 is bonded and fixed on a metal substrate 100 with solder 126, and a lens 120 A configuration in which a metal holder for holding the lens 120) is joined and fixed with solder 121 has also been used.

By the way, various optical devices such as lasers and measuring instruments have been miniaturized, and the optical elements mounted on the substrate have also been reduced in size, and since each element is arranged close to the substrate, The fixed holder 101 is fixed on the substrate with the screw 102 as shown, and the lens holding the lens 110 in the fixed holder 101. In a configuration in which the lens holder 111 is attached, there is a problem that it is difficult to dispose the optical element in close proximity due to the hindrance of these holders and screws, which hinders miniaturization of the device. Also, as shown in Fig. 16, when the holder and the optical element are joined and fixed by soldering, if the optical elements are close to each other, a soldering iron to melt the solder cannot be inserted, and the optical elements must be placed close to each other. And it is difficult to reduce the size of the device.

 As an optical element disposed on the substrate in this manner, for example, there is a wavelength conversion crystal. Among such optical elements, temperature management (management for heating to a desired temperature) is required to maintain the performance. Etc.) are required for some elements. Therefore, an optical element whose temperature is controlled to be high and an optical element which is kept at room temperature is disposed on the substrate, and a temperature difference is generated in the substrate, and the difference in the amount of expansion of the substrate due to the temperature difference is generated. Therefore, there is a problem that the arrangement position of the optical element is shifted. Disclosure of the invention

 The present invention has been made in view of such a problem, and when an optical element is arranged close to a substrate to constitute an optical device, when the temperature of each optical element differs depending on whether or not temperature management is performed, this temperature difference is obtained. It is an object of the present invention to provide an optical device having a configuration capable of suppressing an influence of the optical element on a substrate and suppressing a dislocation position of an optical element on the substrate, and an assembling method thereof.

 Another object of the present invention is to provide an optical device having a configuration in which a plurality of optical elements can be easily arranged and fixed in close proximity on a substrate, and can be made compact, and an assembling method thereof.

In order to achieve such an object, an optical device according to the present invention includes: a substrate (base); an optical system including a plurality of optical elements bonded and fixed on the substrate with an adhesive material; consists of a temperature control device for managing the temperature of the desired optical element, the substrate is thermal expansion coefficient of ^{1 0 - 6 ~ 1 0 -} 9 mZK der Made from the material. Thus the thermal expansion coefficient of 1 ^0-6 -1 0 substrate - by making from ⁹ m / K at which the material, the substrate under the influence of temperature control of this even if the temperature control of the desired optical element There is almost no expansion or contraction, and the position of the optical element on the substrate can be accurately maintained.

 In this case, the plurality of optical elements include an optical element whose temperature is controlled by a temperature control device and an optical element whose temperature is not controlled, and the optical element whose temperature is controlled and the optical element whose temperature is not controlled are mixed on the substrate. And an optical device can be configured.

 Further, an optical device in which at least one of the plurality of optical elements is temperature-controlled by a temperature control device to generate a temperature gradient in the surface of the substrate can be used without any problem.

 The temperature control device has a heat source for heating a desired optical element to a predetermined high temperature.

The thermal expansion coefficient of 1 0 - as the material is ^s ~ l 0- ^{9 mZK,} preferable to use a glass material. ·

 An optical device can be configured by disposing optical elements on both the front and back surfaces of the substrate.

 The substrate is made of a light transmissive material, a first optical path deflecting element is provided on at least one of the front and back surfaces of the substrate, and the light passing through the optical element provided on the one surface is made first. The optical element may be configured to be deflected by the optical path deflecting element, pass through the substrate, and enter the optical element provided on the other surface of the substrate. The first optical path deflecting element deflects light so as to be perpendicularly incident on one surface of the substrate and pass through the substrate, and the second optical path deflecting element disposed on the other surface of the substrate causes the substrate to be deflected by the second optical path deflecting element. May be configured to deflect light passing through the optical element and make the light incident on the optical element provided on the other surface. '

Further, the first optical path deflecting element makes light obliquely incident on one surface of the substrate. Then, the light is deflected so as to pass through the substrate, and the light is split into a plurality of lights corresponding to the wavelengths by the prism function of the substrate and emitted to the opposite surface of the substrate. The second optical path deflecting element provided on the other surface may be configured to be deflected by the second optical path deflecting element and enter the optical element provided on the other surface.

 The material constituting the substrate may have desired filter characteristics with respect to light passing through the substrate.

 Preferably, the substrate is composed of quartz glass.

 It is preferable to fix the holder on the substrate with an adhesive material and fix the optical element on the holder.

 At this time, the holder is preferably made of quartz glass.

 Preferably, the adhesive material is composed of an ultraviolet-curable adhesive.

 A cover member made of quartz glass is mounted on the substrate to which the optical element is adhered and fixed so as to surround the optical element, and the optical element can be disposed in a closed space surrounded by the substrate and the cover member.

On the other hand, in the assembling method of the optical device according to the present invention, the thermal expansion coefficient of 1 0 - ⁶ to a predetermined position on the substrate material made of a 1 0- ⁹ m / K, is temperature controlled by the temperature management system An optical system is formed by positioning a plurality of optical elements including the optical element and bonding and fixing them with an adhesive material.

The thermal expansion coefficient is preferable to use a glass material as the material is ^{1 0- e ~ l 0- 9 mZ} K.

 At this time, it is preferable that the optical element is supported by the position adjusting jig, the optical element is positioned at a predetermined position on the substrate, and the optical element is bonded and fixed on the substrate with an adhesive material in such a state.

The holder may be fixed on the substrate with an adhesive material, and the optical element may be fixed on the holder. An ultraviolet curable adhesive can be used as the adhesive material.

 The substrate may be made of quartz glass, and the ultraviolet curable adhesive may be cured by irradiating ultraviolet light through the substrate.

 A cover member made of quartz glass may be mounted on the substrate to which the optical element is adhered and fixed so as to surround the optical element, and the optical element may be disposed in a closed space surrounded by the substrate and the cover member.

 In this case, when the optical element is bonded and fixed with an ultraviolet-curable adhesive, the ultraviolet-curable adhesive can be hardened by irradiating ultraviolet light through the cover member. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a schematic diagram illustrating a configuration of a wavelength conversion device according to a first embodiment of the present invention.

 FIG. 2 is a side view for explaining a method of mounting an optical element (lens) on a substrate in the wavelength converter.

 FIG. 3 is a side view for explaining a second method for mounting an optical element (lens) on a substrate in the wavelength conversion device.

 FIG. 4 is a side view for explaining a third method of mounting an optical element (lens) on a substrate in the wavelength converter.

 FIG. 5 is a side view for explaining a fourth method for mounting an optical element (wavelength conversion crystal) on a substrate in the wavelength conversion device.

 FIG. 6 is a side view for explaining a fifth method for mounting an optical element (wavelength conversion crystal) on a substrate in the wavelength conversion device.

 FIG. 7 is a schematic diagram illustrating a configuration of a wavelength conversion device according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a configuration of a wavelength conversion device according to a third embodiment of the present invention. It is.

 FIG. 9 is a schematic diagram illustrating a configuration of a wavelength conversion device according to a fourth embodiment of the present invention.

 FIG. 10 is a schematic diagram illustrating a configuration of a wavelength conversion device according to a fifth embodiment of the present invention.

 FIG. 11 is a perspective view showing a configuration of a wavelength conversion device according to a sixth embodiment of the present invention in a state where a substrate is disassembled into constituent parts.

 FIG. 12 is a perspective view showing a configuration of the wavelength conversion device according to the sixth embodiment in a state where a substrate is assembled.

 FIG. 13 is a schematic side view showing a part of the configuration of a wavelength conversion device according to a seventh embodiment of the present invention.

 FIG. 14 is a schematic side view showing a part of a configuration of a wavelength conversion device according to a seventh embodiment of the present invention.

 FIG. 15 is a front view showing an example of mounting a conventional optical element.

 FIG. 16 is a side view showing another example of mounting a conventional optical element. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present invention has a great feature in a configuration in which an optical element is fixedly held on a substrate. The overall configuration of an optical device including a plurality of optical elements fixed and held in this manner is described by taking a wavelength converter as an example. explain. First embodiment

FIG. 1 shows a first embodiment of the wavelength conversion device. This device converts the wavelength of the incident light Li of the fundamental wave (wavelength I550 nm) from the light source 1, Create the output light Lo of the harmonic wave (wavelength around 190 nm). Light source 1 is It consists of a DFB laser that emits light of the main wave and a fiber amplifier that amplifies this light, and the light L i of the fundamental wave amplified by the fiber amplifier enters the wavelength converter. Such a laser and a fiber amplifier are disclosed in Japanese Patent Application Laid-Open No. 2000-200747 filed by the present applicant.

The wavelength conversion device is configured by arranging a number of optical elements on a substrate 5 as shown in FIG. 1, and the arrangement and role of each optical element will be described below along the movement path of incident light. Will be described. The substrate 5 is made of a material having a lower coefficient of thermal expansion than a normal metal (a material having a coefficient of thermal expansion of 10 · ⁶ to 10 · ⁹ · ηηΖΚ), such as a glass material, a ceramic, and a special metal (the main components Ni, Fe , C o), etc., to suppress the thermal expansion of the substrate with respect to a change in ambient temperature, and to minimize the change in position of each optical element arranged on the substrate 5. Further, as described later, it is preferable that the substrate 5 is made of quartz glass so that ultraviolet light or laser light can be passed through the substrate 5 and irradiated.

 As described above, the incident light L i of the fundamental wave incident from the light source 1 into the wavelength converter first enters the dichroic mirror 11 and reflects the pump light used for amplification by the fiber amplifier. Only the fundamental signal light is passed. The signal light that has passed through the dichroic mirror 11 passes through the wave plates 12 and 13 to have a desired polarization state, and enters the first wavelength conversion crystal 31 via the lens 14 and the mirror 15. The first wavelength conversion crystal 31 is composed of an LBO crystal, and a part of the signal light of the fundamental wave incident thereon is converted into a second harmonic. For this reason, the unconverted fundamental signal light and the second harmonic signal light are emitted from the first wavelength conversion crystal 31 and passed through the wave plate 16 and the lens 17 to be converted into the second wavelength. It is incident on crystal 32. The wave plate 16 is for adjusting the polarization state of the fundamental wave to the polarization state of the second harmonic.

The second wavelength conversion crystal 32 is composed of an LBO crystal, The wavelength and a part of the second-harmonic signal light are wavelength-converted into third-harmonic waves, and the fundamental, second-harmonic, and third-harmonic signal lights are emitted from the second wavelength conversion crystal 32. As described above, of the signal light emitted from the second wavelength conversion crystal 32, the second and third harmonic signal lights are reflected by the dichroic mirror 18, and the fundamental wave signal light is reflected by the dichroic mirror 1 The light passes through 8 and is reflected by the reflecting mirror 23.

 The second- and third-harmonic signal lights reflected by the dichroic mirror 18 enter the third wavelength conversion crystal 33 via the lens 19. The third wavelength conversion crystal 33 is composed of a GdYCOB crystal, and a part of the second-harmonic signal light incident thereon is wavelength-converted into a fourth-harmonic signal light. Then, the signal lights of the fourth and third harmonics are emitted from the third wavelength conversion crystal 33, and the light thus emitted is incident on the fourth wavelength conversion crystal 34 via the lens 20. The fourth wavelength conversion crystal 33 is composed of a BBO crystal, and a part of the third- and fourth-harmonic signal light incident thereon is wavelength-converted into the seventh-harmonic wave. The seventh harmonic signal light emitted from the fourth wavelength conversion crystal 34 is reflected by the dichroic mirror 27 via the lenses 21 and 22.

 On the other hand, the signal light of the fundamental wave transmitted through the dichroic mirror 18 and reflected by the reflecting mirror 23 is reflected by the reflecting mirror 26 via the lenses 24 and 25, and passes through the dichroic mirror 27. To Penetrate. Therefore, the signal light of the seventh harmonic reflected by the dichroic mirror 27 and the signal light of the fundamental wave transmitted through the dichroic mirror 27 are coaxially overlapped as described above, and the fifth wavelength conversion crystal 35 Incident on. The fifth wavelength conversion crystal 35 is composed of a CLBO crystal, and the fundamental wave and a part of the seventh harmonic signal light are wavelength-converted to the eighth harmonic signal light. Therefore, the fifth wavelength conversion crystal 35 emits the signal light of the fundamental wave, the signal light of the seventh harmonic, and the signal light of the eighth harmonic that have not been wavelength-converted, and this is reflected by the reflecting mirror 28. The light is reflected and emitted out of the device as the emission signal light Lo.

In the wavelength converter having the above-described configuration, the reflecting mirror 28 is configured to output the light L 0. It is for setting the emission direction and does not contribute to wavelength conversion. Also, when beam shaping or the like is required in the device, it is necessary to additionally provide lenses and the like accordingly. Further, the types of the crystals constituting the first to fifth wavelength conversion crystals 31 to 35 are only examples, and the first to third wavelength conversion crystals 31 1, 3 2, 3 As 3, there are PP LN, PPL II, PPK PT, etc., and as the fifth wavelength conversion crystal 35, LBO, BBO, etc. can be considered. However, it is necessary to change the wave plate and lens according to the type of crystal used.

 When the first and second wavelength conversion crystals 31 and 32 are composed of LBO crystals as described above, and when the third wavelength conversion crystal 33 is composed of GdYCOB crystal, these crystals are respectively used. Desirably, the temperature is set to a desired value to achieve non-critical phase matching. The fifth wavelength conversion crystal 35 composed of a CLBO crystal is preferably kept at a temperature of about 150 degrees Celsius to keep it dry. The fourth wavelength conversion crystal 34 made of BBO crystal is critically phase-matched, so there is basically no need to adjust the temperature. However, if there is an effect of the temperature around the crystal, If the internal temperature distribution is not uniform), the temperature of the entire BBO crystal is stabilized by adjusting the temperature of the BBO crystal, and the power fluctuation of the wavelength-converted light can be suppressed.

For this reason, although not shown, a temperature management device or a heating device is provided corresponding to an optical element (wavelength conversion crystal) requiring temperature management (management for heating to a desired temperature) as described above. When only the necessary wavelength conversion crystal is subjected to temperature control or heat control in this way, the remaining optical elements remain at room temperature, and the surface temperature distribution of the substrate 5 becomes non-uniform, resulting in a temperature gradient. However, since the substrate 5 is made of a glass material having a small coefficient of thermal expansion as described above, the amount of thermal expansion of the substrate 5 is extremely small even if there is a temperature gradient, and the substrate 5 is disposed on the substrate 5. The position change of each optical element is very small. Optical element assembling method

 As described above, the wavelength conversion device is assembled by positioning and arranging optical elements such as lenses, mirrors, wavelength plates, wavelength conversion crystals, and the like at predetermined positions on the substrate 5 made of quartz glass. The method for positioning and mounting each optical element will be described below. In the following, a method of positioning and mounting the lens Ls on the substrate 5 as a representative of the optical element will be described.

 First, FIG. 2 shows the first mounting method, in which a holder 51 for roughly adjusting the height to the substrate 5 is bonded with an adhesive 52, and the lens Ls is placed on the holder 51 with an ultraviolet ray. They are joined and fixed with a curable adhesive 53 (hereinafter referred to as UV adhesive). However, the holder 51 only roughly adjusts the height, and accurate position adjustment (fine adjustment) is required when bonding the lens Ls on the holder 51. For this reason, an adjustment jig 55 is arranged outside the substrate 5, and the lens L s is gripped by the holding tool 57 attached to the tip of the arm 56 of the adjustment jig 55, and the lens L s is held. Position adjustment is performed. The adjustment jig 66 is placed on an XYZ stage (not shown), and the position of the lens Ls is adjusted by adjusting the movement of the gripper 57 in the XYZ directions. When the position adjustment is completed, the UV adhesive 53 is irradiated with ultraviolet light to cure it, and the lens Ls is accurately positioned and mounted in a predetermined position. Thereafter, the adjusting jig 55 is mounted. Remove and complete the installation of lens L s. At this time, the UV adhesive 53 can be irradiated with ultraviolet light through the quartz glass substrate 5, which is very convenient. In addition, the holder 51 may be bonded to the substrate 5 with a UV adhesive.

Fig. 3 shows the second mounting method. When height adjustment using the holder 51 is not required, as shown in Fig. 3, a UV adhesive 54 It is also possible to position and join the lens Ls. At this time, the position of the lens Ls is adjusted using a position adjusting jig 55 as shown in FIG.

 FIG. 4 shows a third mounting method. In this case, the first holder 61 is adhered to the substrate 5 with the UV adhesive 64, and a hollow cylindrical shape is mounted on the first holder 61. The second holder 62 is bonded with a UV adhesive 65. In addition, a cylindrical third holder 63 is attached to the lens LS with a UV adhesive 66, and this third holder 63 is fitted into the hollow cylindrical space of the second holder 62, and the UV adhesive 6 Attach it in 2a. As a result, height adjustment based on the thickness of the UV adhesive is eliminated, and the problem of the thickness change due to the temperature change of the UV adhesive 64, 65, 66 is almost eliminated.

 In the above mounting method, the method of fixing the lens and the holder using UV adhesive is used, but once the UV adhesive is cured, it can not be removed and the position cannot be readjusted. It is. Therefore, in the following fourth and fifth attachment methods, solder is used instead of the UV adhesive.

 FIG. 5 shows a fourth mounting method, in which an example of mounting the wavelength conversion crystal 70 held by the holder 71 to the substrate 5 is shown. The legs 7 2 of the holder 7 1 are joined to the surface of the board 5 by the solder 7 3 .In this case, the holder 7 1 is removed from the board 5 by heating the solder 7 3, and the position is adjusted again. It can be performed. As a method for melting the solder 73, a heater may be attached to the holder 71, or a laser beam may be irradiated from outside to heat the solder joint.

FIG. 6 shows a fifth mounting method, in which a concave portion 5 a is formed in the substrate 5, and the leg portion 72 of the holder 71 is fixed and held by the solder 75 in the concave portion 5 a. The holder 71 holds the wavelength conversion crystal 70 This is the same configuration as in FIG. In this case, the adjustment range in the height direction of the legs 72 can be made wider than in the case of FIG. Second embodiment

 FIG. 7 shows a wavelength converter according to the second embodiment. In this device, the same optical element as that of the device shown in FIG. 1 is arranged on a substrate 5 made of a glass material (quartz glass). Above, an enclosure 6 made of quartz glass is attached around the upper surface of the substrate 5. Note that the optical elements disposed on the substrate 5 are exactly the same as those of the device according to the first embodiment in FIG. 1, and therefore, the same parts are denoted by the same reference numerals and description thereof will be omitted.

 Quartz glass is transparent to all wavelengths up to the above-mentioned fundamental wave (1550 nm) and the 8th harmonic (1900 ηm), so that incident light Li and output light It is not necessary to provide an opening in a portion through which Lo passes, and all the optical elements provided on the substrate 5 can be hermetically provided in the internal space covered by the enclosure 6. For this reason, the ambient temperature and humidity of the optical element can be appropriately controlled, and for example, a wavelength conversion crystal that is sensitive to humidity can be held in a dry atmosphere to prevent a decrease in its performance. In this case, when silica gel is used as a dehumidifying agent inside, since the substrate 5 and the enclosure 6 are transparent, the life of the gel can be easily visually judged from the outside. In addition, in order to suppress the occurrence of the chemical cleaning phenomenon (a phenomenon in which the glass surface is fogged by ultraviolet light, which is considered to be due to the presence of organic substances), each optical element is blocked from the outside air to prevent the entry of organic substances, It is also possible to purge the internal space with nitrogen.

In addition, it is possible to apply an AR coating to a portion of the enclosure 6 through which the incident light L i and the outgoing light L o pass, so that a high transmittance can be set for an arbitrary wavelength. Further, even if a mechanism for monitoring the wavelength converted by each wavelength conversion crystal is added to this device, the monitor light is surrounded. It can be easily taken out.

 Also in this embodiment, a temperature management device or a heating device may be provided corresponding to an optical element (wavelength conversion crystal) requiring temperature management (management for heating to a desired temperature) to perform temperature management or heating management. . In this case, since the remaining optical elements remain at room temperature, the surface temperature distribution of the substrate 5 becomes uneven and a temperature gradient occurs, but since the substrate 5 is made of a glass material having a small coefficient of thermal expansion, Even if there is a temperature gradient, the amount of thermal expansion of the substrate 5 is extremely small, and the position change of each optical element arranged on the substrate 5 is very small. Third embodiment

 FIG. 8 shows a third embodiment. In this apparatus, the same optical element as that of the apparatus shown in FIG. 1 is provided on a substrate 5 made of a glass material (quartz glass), and the upper surface of the substrate 5 is covered as shown in FIG. Box 7 is installed. The optical elements provided on the substrate 5 are exactly the same as those of the device according to the first embodiment shown in FIG. 1, and therefore, the same parts are denoted by the same reference numerals and description thereof will be omitted.

In this wavelength converter, the above-described chemical cleaning phenomenon occurs in an optical element that receives signal light that is ultraviolet light having a short wavelength. For this reason, the dichroic mirror 11 and the wave plates 12 and 13 which receive the incident light L i from the light source 1 which is light in the near-infrared region and the chemical cleaning phenomenon hardly causes a problem are enclosed. It is arranged outside of 7, and the remaining optical elements are covered with an enclosure 7. Then, the incident light Li passing through the dichroic mirror 11 and the wave plates 12 and 13 passes through the inclined portion 7a of the enclosure 7 and enters the interior space of the enclosure 7. a is set so that the inclination angle with respect to the optical axis becomes the Brewster angle with respect to the fundamental wave, and the signal light of the fundamental wave can be incident into the internal space with high transmittance. Also, this W

By monitoring the fundamental wave reflected on the outer surface of the inclined portion 7a, the polarization state of the fundamental wave can be known.

 The output signal light Lo, which is wavelength-converted by the wavelength conversion device and reflected and emitted by the reflecting mirror 28, is transmitted through the prism portion 7b formed in the enclosure 7 and emitted to the outside. ing. Due to the prism action of the prism part 7b, the output signal light Lo is emitted at different refraction angles corresponding to the wavelengths, and is eight times higher than the output signal light Lo mixed with the fundamental wave, the seventh harmonic and the eighth harmonic. Waves can be separated. At this time, if the inclination angle of the prism portion 7b is set so as to be a Brewster angle with respect to the eighth harmonic, it is possible to emit the eighth harmonic with a high transmittance.

 In this case as well, it is possible to appropriately manage the ambient environmental temperature and humidity of the optical element disposed in the internal space covered by the enclosure 7. For example, a wavelength-converting crystal that is sensitive to humidity can be kept in a dry atmosphere to prevent its performance from deteriorating.For this reason, when silica gel is used inside, the substrate 5 and the enclosure 7 are transparent, so the life of silica gel is Can be easily determined visually. The internal space may be purged with nitrogen to suppress the occurrence of the chemical cleaning phenomenon.

In the above configuration, for example, if an optical element requiring temperature control or heating control is arranged in the internal space covered by the enclosure 7 and the temperature inside the enclosure 7 is controlled, the outside of the enclosure 7 Is kept at room temperature, the surface temperature distribution of the substrate 5 becomes uneven, and a temperature gradient occurs. However, since the substrate 5 is made of a glass material having a low coefficient of thermal expansion, the amount of thermal expansion of the substrate 5 is extremely small even with such a temperature gradient, and each optical element arranged on the substrate 5 Is very small. Fourth embodiment FIG. 9 shows a fourth embodiment. In this apparatus, the same optical element as that of the apparatus shown in FIG. 1 is provided on a substrate 5 made of a glass material (quartz glass), and the upper surface of the substrate 5 is covered as shown in FIG. Box 8 is installed. The enclosure 8 has an outer peripheral portion 8a that covers the outer peripheral side surface and a partition wall 8b that divides the internal space into two, and the closed space surrounded by the substrate 5 and the enclosure 8 is partitioned by the partition wall 8b. Thus, first and second sealed rooms R 1 and R 2 are formed. Note that the optical elements disposed on the substrate 5 are exactly the same as those of the device according to the first embodiment in FIG. 1, and therefore, the same parts are denoted by the same reference numerals and description thereof will be omitted.

 In this wavelength converter, an optical element through which signal light of the 7th and 8th harmonics, which is light in the ultraviolet region, passes is disposed in the second room R2, and nitrogen is passed through the second room R2. Purging is used to suppress the occurrence of the above-mentioned chemical cleaning phenomenon. In addition, in both the first and second rooms Rl and R2, the ambient environment temperature and humidity of the optical elements provided therein can be appropriately managed. For example, a wavelength-converting crystal that is sensitive to humidity can be held in a dry atmosphere to prevent its performance from deteriorating. Similarly to the above, when silica gel is used inside, the substrate 5 and the enclosure 8 are transparent, The life of the force gel can be easily visually determined from the outside.

In the above configuration, for example, if the inside of the first and second rooms R l and R 2 is controlled to a desired temperature according to the optical elements disposed therein, the surface temperature of the substrate 5 will be reduced. The distribution becomes uneven and a temperature gradient occurs. However, since the substrate 5 is made of a glass material having a small coefficient of thermal expansion as described above, the amount of thermal expansion of the substrate 5 is extremely small even with such a temperature gradient, and The change in position of each of the arranged optical elements is very small. Fifth embodiment FIG. 10 shows a fifth embodiment. Also in this apparatus, the same optical element as the apparatus in FIG. 1 is disposed on a substrate 5 made of a glass material (quartz glass). Although not shown, it is preferable to provide an enclosure on the substrate 5 as in the above embodiment. Since the optical elements provided on the substrate 5 are the same except for the first and second wavelength conversion crystals, the same parts are denoted by the same reference numerals and description thereof will be omitted.

 In this apparatus, the first and second wavelength conversion crystals 31 ′ and 32 ′ are configured using QPM elements such as PPLN, PPPTP, and PPLT instead of LBO crystals. Since this QPM device can perform non-critical phase matching at any temperature, the first to fifth wavelength conversion crystals 31, 32 ′, 33, 33, 34, and 35 are arranged on the substrate 5. Can be adjusted to the same temperature, and the number of wires and power consumption for temperature control can be reduced.

 In this apparatus, heat from a heat source 80 with a temperature controller is transferred to all crystals by a heat pipe 81 to control the temperature of these crystals. As described above, this temperature management can be performed by installing a temperature sensor for a wavelength conversion crystal requiring a temperature setting and adjusting the temperature. In addition, when it is not necessary to set the temperature for all wavelength conversion crystals, a temperature sensor may be installed at an arbitrary position to perform temperature control according to the crystal to be used, such as avoiding deliquescence and preventing light damage.

When the temperature of each wavelength conversion crystal is controlled using the heat pipe 81 as described above, the surface temperature distribution of the substrate 5 becomes non-uniform because a temperature of other optical elements is at room temperature, and a temperature gradient occurs. However, as described above, since the substrate 5 is made of a glass material having a small coefficient of thermal expansion, the amount of thermal expansion of the substrate 5 is extremely small even with such a temperature gradient, and The change in the position of each of the optical elements arranged in the area is very small. Sixth embodiment

 A sixth embodiment is shown in FIG. 11 and FIG. In this apparatus, a substrate 5 'made of a glass material (quartz glass) is composed of a heat source plate 85 with a temperature controller, and upper and lower substrate plates 86, 87 sandwiching the heat source plate 85 from above and below. . On the heat source plate 85, first to fifth wavelength conversion crystals 31 to 35 requiring temperature control are arranged. Openings 86a to 86e are formed in the upper substrate plate 86 so that the first to fifth wavelength conversion crystals 31 to 35 are inserted therethrough, and the upper substrate plate 86 is a heat source plate 85 The first to fifth wavelength conversion crystals 31 to 35 protrude from the upper surface as shown in FIG. Then, another optical element is disposed on the upper substrate plate 86, for example, as shown in FIG.

 The heat source plate 85 is maintained at the temperature set by the temperature controller, and all of the first to fifth wavelength conversion crystals 31 to 35 installed thereon have the temperature set in this manner. The heat source plate 85 with a controller is provided with a heat source such as a heater and a temperature sensor such as a platinum resistance Z thermistor, and is made of a material having a high thermal conductivity such as aluminum, copper, and (certain) ceramics. If glass is used for the upper substrate plate 86 on which the optical element is installed, it can be bonded and fixed by UV hardening resin. Further, since glass has a low thermal conductivity, heat from the heat source plate 85 can be prevented from being transmitted to the optical components installed on the upper substrate plate 86. When there is no problem even if all the optical elements used have the same high temperature, the upper substrate plate 86 may be omitted and all the optical elements may be installed on the heat source plate 85.

When the temperature control of each wavelength conversion crystal is performed using the heat source plate 85 as described above, the surface temperature distribution of the substrate 5 becomes non-uniform because the other optical elements are at room temperature, and a temperature gradient occurs. However, since the substrate 5 is made of a glass material having a small coefficient of thermal expansion as described above, even if there is such a temperature gradient, the heat of the substrate 5 can be reduced. The amount of expansion is extremely small, and the position change of each optical element arranged on the substrate 5 is very small. Seventh embodiment

 FIG. 13 shows a seventh embodiment. In the above-described embodiment, the wavelength converter has been specifically illustrated and described. Here, a part of the wavelength converter is extracted and shown. This optical device has a flat substrate 150 made of a light-transmitting glass material (for example, quartz glass), and has an upper surface (surface) 150a and a lower surface (back surface) 150a. 50b is provided with a plurality of optical elements as shown. First, the first lens 151, the wavelength conversion element 152, and the second lens 153 are disposed on the upper surface 150a along the optical axis of the incident light L i parallel to the upper surface 150a. And a first reflecting mirror 154 are provided, and a second reflecting mirror 155 and a third lens 156 facing vertically above and below the substrate 150 are provided on the lower surface 150b. ing.

 The first to third lenses 15 1, 15 3, 15 6 are mounted on the substrate 15 0 via holders 15 1 a, 15 3 a, 15 56 a, respectively. The length conversion element 152 is mounted on the substrate 150 via the holder 152a. The attachment of the lens and the wavelength conversion element via these holders is performed by using the above-described optical element assembling method.

In the optical device having the above configuration, the incident light L i of the first wavelength parallel to the upper surface 150 a of the substrate 150 enters the wavelength conversion element 15 2 through the first lens 15 1, Part of the light is wavelength-converted into light of the second wavelength. For this reason, light of the first and second wavelengths is emitted from the wavelength conversion element 15 2, and after passing through the second lens 15 3, hits the reflecting surface 15 5 a of the first reflecting mirror 15 4 Is reflected. The reflecting surface 154a is inclined 45 degrees with respect to the upper surface 150a of the substrate 150, and the light reflected by the reflecting surface 154a is perpendicularly incident on the substrate 150. I do. Since the substrate 150 has a light transmitting property, this light passes through the substrate 150 and is reflected by the reflecting surface 150a of the second reflecting mirror 150. The reflecting surface 150a is inclined by 45 degrees with respect to the lower surface 150b of the substrate, and the light reflected on the reflecting surface 150a extends parallel to the lower surface 150b and the third lens 1b. The light passes through 5 6 and becomes the output signal light Lo. Here, it is the light having the first and second wavelengths that causes the light reflected by the reflecting surface 154a to be perpendicularly incident on the substrate 150. This is because the light of the two wavelengths is not split. When light of two wavelengths may be separated, the light may be obliquely incident on the substrate 150.

 As described above, in the device of the seventh embodiment, the optical elements are arranged on the upper and lower surfaces of the substrate 150, and the light is reflected by using the reflecting mirrors 154 and 155 facing each other, so that the substrate 150 Since optical signals are transmitted and received between the upper and lower surfaces of the substrate, optical elements disposed on the upper and lower surfaces of the substrate can be organically connected to form an optical device. Therefore, the optical device can be configured to be small and compact by effectively utilizing the upper and lower surfaces of the substrate. Note that FIG. 13 shows an example in which light is transmitted only once through the substrate 150 by a pair of reflecting mirrors 154 and 155 facing up and down. A configuration may be adopted in which a pair of reflecting mirrors is provided and the light is reflected a plurality of times. In addition, by appropriately selecting the material of the substrate 150, it is possible to have a function as a wavelength filter according to the light transmission characteristics of this material. Note that another optical path deflecting element, for example, a prism may be used instead of the reflecting mirror. Eighth embodiment

An eighth embodiment is shown in FIG. In this embodiment, as in the seventh embodiment, a part of the wavelength converter is taken out and shown. This optical device is made of a light transmissive glass material (eg, quartz glass). A flat substrate 160 is provided, and a plurality of optical elements are provided on the upper surface 160a and the lower surface 160b as shown in the figure. First, the first lens 161, the wavelength conversion element 162, and the first reflecting mirror 16 are arranged on the upper surface 16a along the optical axis of the incident light L i parallel to the upper surface 16a. 3 is provided, and on the lower surface 160 b, second and third reflecting mirrors 165 and 166 which are obliquely opposed to each other across the substrate 160 are provided. The first lens 161 and the wavelength conversion element 162 are mounted on the substrate 160 via the holders 16a and 162a. Is performed by using the assembling method described above. In the optical device having the above configuration, the incident light Li of the first wavelength enters the wavelength conversion element 162 through the first lens 161, and a part of the light is converted into light of the second wavelength. Is done. For this reason, light of the first and second wavelengths is emitted from the wavelength conversion element 162, and impinges on the reflecting surface 1663a of the first reflecting mirror 163 and is reflected obliquely downward. The reflecting surface 163a is inclined as shown in the figure with respect to the upper surface 160a of the substrate 160, and the light reflected by the reflecting surface 163a is obliquely incident on the substrate 160. The light obliquely incident as described above is separated into a first wavelength light and a second light wavelength by the prism function of the substrate 160 and is emitted from the lower surface 160 b of the substrate 160. .

 On the lower surface of the substrate 160, the second and third reflecting mirrors 165, 166 and the reflecting surfaces 165a, 166a are separated by the prism function as described above. And light at the second wavelength. For this reason, the light of the first and second wavelengths is reflected by the reflecting surfaces 1665a and 1666a, respectively, and becomes the first and second output signal lights Lo (1) and Lo (2). Is emitted.

As described above, in the device of the present embodiment, the light after wavelength conversion can be divided according to the wavelength by obliquely incident light on the substrate 160, and each of the light is converted into a desired optical element. It is possible to separate and enter. Substrate 1 If the separation of the light of the first and second wavelengths is small by merely transmitting the light once, the separation distance can be increased by repeatedly transmitting the light through the substrate 160 a plurality of times.

 Further, in the device of the eighth embodiment, similarly to the seventh embodiment, optical elements are provided on both the upper and lower surfaces of the substrate 160, and the optical elements are arranged on the upper and lower surfaces by using the reflecting mirrors 16 3, 16 5 and 16 6. Since the optical signal is exchanged between the lower surfaces, the upper and lower surfaces of the substrate can be effectively used, and the optical device can be made compact and compact. In addition, by appropriately selecting the material of the substrate 160, it is possible to provide a function as a wavelength filter according to the light transmission characteristics of this material. Note that another optical path deflecting element, for example, a prism may be used instead of the reflecting mirror. In the above embodiments (first to eighth embodiments), the wavelength converter is described as an example of the optical device according to the present invention. However, the optical device of the present invention is not limited to this. It can be applied to various optical devices. As described above, according to the present invention, an optical device is configured by bonding and fixing an optical element to a predetermined position on a substrate with an adhesive material, so that the optical element can be disposed close to and fixed on the substrate. This makes it easier to reduce the size of the device.

Claims

Scope of demand 1. The substrate and  An optical system including a plurality of optical elements bonded and fixed on the substrate with an adhesive material;  A temperature management device that manages a temperature of a desired optical element among the plurality of optical elements; Wherein the substrate, the optical device comprising that you thermal expansion coefficient is made from a material which is ^{1 0- 6 ~1 0- 9 m /} K. 2. The plurality of optical elements comprises an optical element whose temperature is controlled by the temperature control device and an optical element whose temperature is not controlled by the temperature control device,  2. The optical device according to claim 1, wherein the optical element whose temperature is controlled and the optical element whose temperature is not controlled are mixed and disposed on the substrate. 3. The optical device according to claim 1, wherein at least one of the plurality of optical elements is temperature-controlled by the temperature management device to generate a temperature gradient in a plane of the substrate. 4. The optical device according to claim 1, wherein the temperature management device has a heat source for heating the desired optical element to a predetermined high temperature. 5. The optical device according to claim 4, wherein the material is a glass material. 6. The optical device according to claim 5, wherein the optical element is provided on each of the front and back surfaces of the substrate. The substrate is made of a light-transmitting material, a first optical path deflecting element is provided on at least one of the front and back surfaces of the substrate, and passes through an optical element provided on the one surface. 7. The device according to claim 6, wherein the light is deflected by the first optical path deflecting element, passes through the substrate, and enters the optical element disposed on the other surface of the substrate. An optical device according to claim 1. The first optical path deflecting element deflects the light so as to be perpendicularly incident on one surface of the substrate and pass through the substrate, and a second optical path deflection disposed on the other surface of the substrate. The optical device according to claim 7, wherein the optical device is configured to deflect light that has passed through the substrate by an element and to make the light incident on the optical element provided on the other surface. The first optical path deflecting element deflects the light so that the light is obliquely incident on one surface of the substrate and passes through the substrate. The prism function of the substrate causes the light to correspond to a plurality of wavelengths. And the light that has passed through the substrate and is split is deflected by the second optical path deflecting element disposed on the other surface, and the other light is deflected. 8. The optical device according to claim 7, wherein the optical device is configured to be incident on the optical element provided on the surface of the optical device. 0. The optical device according to any one of claims 7 to 9, wherein the material constituting the substrate has a desired filter characteristic for light passing through the substrate. 1. The substrate according to any one of claims 1 to 10, wherein the substrate is made of quartz glass. An optical device according to any of the preceding claims. 12. The optical device according to claim 1, wherein a holder is bonded and fixed on the substrate with an adhesive material, and the optical element is bonded and fixed on the holder. 13. The optical device according to claim 12, wherein the holder is made of quartz glass. 14. The optical device according to claim 1, wherein the adhesive material is made of an ultraviolet curable adhesive. 15. A quartz glass cover member surrounding the optical element is mounted on the substrate to which the optical element is adhered and fixed, and the optical element is placed in a closed space surrounded by the substrate and the cover member. The optical device according to claim 1, wherein the optical device is provided. 16. Thermal expansion coefficient is a predetermined position on the substrate made of the material is ^{10 · 6 ~1 9 m / K} , and repositioning of the plurality of optical elements including an optical element which is temperature controlled by a temperature control apparatus adhesive material A method for assembling an optical device, comprising: forming an optical system by bonding and fixing the optical device. 17. The method for assembling an optical device according to claim 16, wherein the material is a glass material. 18. Support the optical element with a position adjusting jig and place the optical element on the substrate. The optical element is adhered and fixed on the substrate with the adhesive material in such a state that the optical element is positioned at the predetermined position. 16. The method for assembling the optical device according to 16 or 17. 19. The method for assembling an optical device according to any one of claims 16 to 18, wherein a holder is adhesively fixed on the substrate with an adhesive material, and the optical element is adhesively fixed on the holder. . 20. The method for assembling an optical device according to any one of claims 16 to 19, wherein the adhesive material comprises an ultraviolet curable adhesive. 21. The assembly method according to claim 20, wherein the substrate is made of quartz glass, and the ultraviolet curing adhesive is cured by irradiating ultraviolet light through the substrate. 22. A cover member made of quartz glass is mounted on the substrate on which the optical element is adhered and fixed, surrounding the optical element, and the optical element is enclosed in a closed space surrounded by the substrate and the cover member. The assembly method according to any one of claims 16 to 19, wherein the assembly method is provided in a housing. 23. A quartz glass cover member surrounding the optical element is mounted on the base plate to which the optical element is adhered and fixed, and the optical element is enclosed in a sealed space surrounded by the substrate and the cover member. Arranged in the  22. The assembly method according to claim 20, wherein the ultraviolet curable adhesive is cured by irradiating ultraviolet light through the force member.