JP2009015039A - Method for manufacturing optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve manufacturing work efficiency of an optical element and obtain stable characteristics. <P>SOLUTION: A first composite substrate (21), which is made by sticking a dummy material substrate to a wavelength conversion crystal substrate, is stuck to a laser crystal substrate (11) to form a second composite substrate (22). A cutout (K) is formed to the second composite substrate (22), to which reflective mirror coating (21c, 11c) is applied and which is cut with a line (C), thus obtaining the plurality of optical elements (9). Sticking works would be easier and the manufacturing work efficiency can be improved. Since they can be stuck to each other with stable quality, dispersion is eliminated and stable characteristics can be acquired. Cracking and detachment of bonding of the laser crystal substrate (11) can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical element, and more particularly to a method for manufacturing an optical element that can improve working efficiency and obtain stable characteristics.

An optical element having a structure in which a laser crystal and a wavelength conversion crystal are integrated and a manufacturing method thereof are known (see Patent Document 1).
Furthermore, a manufacturing method of a ferroelectric crystal having a periodic domain-inverted structure inside is known (see Patent Document 2).
JP 2005-57043 A JP-A-2005-208197

  In an optical element having a structure in which a laser crystal and a wavelength conversion crystal are integrated, it is necessary to attach and integrate the laser light emission surface of the laser crystal and the laser light incident surface of the wavelength conversion crystal during manufacture. Here, if both the laser light emitting surface of the laser crystal and the laser light incident surface of the wavelength conversion crystal can have a large area, there is no difficulty in bonding. However, the laser light incident surface of the wavelength conversion crystal may have a narrow area. For example, in a wavelength conversion crystal that needs to form a periodic domain-inverted structure in the crystal, the crystal thickness cannot be increased due to restrictions on the aspect ratio of the period of domain inversion of the periodic domain-inverted structure and the crystal thickness in the polarization direction. The laser light incident surface becomes a small area. In such a case, it is difficult to bond and integrate the laser light emitting surface of the laser crystal and the laser light incident surface of the wavelength conversion crystal, resulting in poor work efficiency. Further, it is difficult to bond with a stable quality, and there are problems that the characteristics differ depending on the location within the bonded surface, and the characteristics vary between optical elements.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical element capable of improving manufacturing work efficiency and obtaining stable characteristics, and a method for manufacturing the same.

In the first aspect, the present invention provides the optical axis side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A dummy substrate of plate-like material is attached to at least one surface partitioned by the width direction side to form a first composite substrate (21), and the width direction side and the thickness direction of the first composite substrate (21) A laser light incident surface (12i) partitioned by a side and a plate-like body, the one surface of which is the laser light emission surface (11o), the surface having the laser light emission surface (11o) of the laser crystal substrate (11) To the second composite substrate (22), and cut into the laser crystal substrate (11) of the second composite substrate (22) along a line (C) to be cut as a plurality of optical elements (9) ( K), after which reflection mirror coating (11c, 21c) is applied, then the front Was cut with the line (C) to provide a method of manufacturing an optical element, characterized in that to obtain a plurality of optical elements (9).
In the optical element manufacturing method according to the first aspect, the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is bonded to the laser crystal substrate (11). Since it is bonded to the laser crystal substrate (11) with the bonding area combined with the dummy material substrate, the bonding operation is much longer than the operation of bonding only the wavelength conversion crystal substrate to the laser crystal substrate (11). It becomes easy. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Moreover, a some optical element (9) can be manufactured collectively.

Further, when the reflection mirror coating is applied to the laser crystal substrate (11) without making the cut (K), the first composite substrate is caused by the temperature rise during film formation (generally around 200 ° C. in film formation) and the film stress. (21) and the laser crystal substrate (11) are warped in opposite directions, and the laser crystal substrate (11) may be cracked or peeled off.
However, in the method for manufacturing an optical element according to the first aspect, the laser crystal substrate (11) is not cut (K), and the reflection mirror coating is applied, so that the laser crystal substrate (11) is not cracked or peeled off. Occurrence can be prevented. This is because the laser crystal substrate (11) having a large area is separated into sections having a small area by a cut (K), and thus warpage and stress in each section are reduced.
In addition to making a cut (K) in the laser crystal substrate (11), a cut may also be made in the first composite substrate (21) side.

In a second aspect, the present invention relates to the optical axis direction side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A dummy substrate of plate-like material is attached to at least one surface partitioned by the width direction side to form a first composite substrate (21), and the width direction side and the thickness direction of the first composite substrate (21) A laser light incident surface (12i) partitioned by a side and a plate-like body, the one surface of which is the laser light emission surface (11o), the surface having the laser light emission surface (11o) of the laser crystal substrate (11) To the second composite substrate (22), and a mask (11) on the laser crystal substrate (11) of the second composite substrate (22) along a line (C) cut as a plurality of optical elements (9). After applying M), apply reflective mirror coating (11c, 21c), then front Was cut with the line (C) to provide a method of manufacturing an optical element, characterized in that to obtain a plurality of optical elements (9).
In the optical element manufacturing method according to the second aspect, the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is bonded to the laser crystal substrate (11). Since it is bonded to the laser crystal substrate (11) with the bonding area combined with the dummy material substrate, the bonding operation is much longer than the operation of bonding only the wavelength conversion crystal substrate to the laser crystal substrate (11). It becomes easy. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Moreover, a some optical element (9) can be manufactured collectively.

Furthermore, when the reflective mirror coating is applied to the laser crystal substrate (11) without attaching the mask (M), the first composite substrate is caused by a temperature rise during film formation (about 200 ° C. in general film formation) and film stress. (21) and the laser crystal substrate (11) are warped in opposite directions, and the laser crystal substrate (11) may be cracked or peeled off.
However, in the method of manufacturing an optical element according to the second aspect, since the reflective mirror coating is applied after the mask (M) is attached to the laser crystal substrate (11), it is possible to prevent the occurrence of cracks and peeling of the adhesive. This is because the reflection mirror coating is separated into smaller sections by the mask (M), so that warpage and stress in each section are reduced.
In addition to attaching the mask (M) to the laser crystal substrate (11), a mask may also be attached to the first composite substrate (21) side.

In a third aspect, the present invention provides the method for manufacturing an optical element according to the second aspect, wherein the mask (M) is a metal plate.
In the optical element manufacturing method according to the third aspect, since the mask (M) is a metal plate, the mask (M) after the reflection mirror coating can be easily removed.

In a fourth aspect, the present invention provides the method for manufacturing an optical element according to the second aspect, wherein the mask (M) is a photo-registry or polyimide, and the lift-off method is performed before or after cutting at the line (C). The method of manufacturing an optical element is provided.
In the method for manufacturing an optical element according to the fourth aspect, since the mask (M) is a photo-registry or polyimide, adhesion to the laser crystal substrate (11) is improved.

In a fifth aspect, the present invention relates to the optical axis direction side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A plate-like dummy material substrate is attached to at least one surface defined by the widthwise sides to form a first composite substrate (21), and a reflective mirror coating (21c) is applied to the first composite substrate (21). On the other hand, a reflection mirror coating (11c) is applied to the other surface of the laser crystal substrate (11), which is a plate-like body, one surface of which is the laser light emission surface (11o), and the reflection mirror coating (21c) is applied. The laser light of the laser crystal substrate (11) having the laser light incident surface (12i) partitioned by the width direction side and the thickness direction side of the first composite substrate (21) and the reflection mirror coating (11c). A surface with an exit surface (11o) and The second composite substrate (22) is pasted, and the second composite substrate (22) is cut along a line (C) to be cut as a plurality of optical elements (9) to obtain a plurality of optical elements (9). An optical element manufacturing method is provided.
In the optical element manufacturing method according to the fifth aspect, the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is bonded to the laser crystal substrate (11). Since it is bonded to the laser crystal substrate (11) with the bonding area combined with the dummy material substrate, the bonding operation is much longer than the operation of bonding only the wavelength conversion crystal substrate to the laser crystal substrate (11). It becomes easy. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Moreover, a some optical element (9) can be manufactured collectively.

Furthermore, when a reflective mirror coating is applied to the second composite substrate (22) obtained by bonding the first composite substrate (21) and the laser crystal substrate (11), the temperature rise during film formation (200 in general film formation). The first composite substrate (21) and the laser crystal substrate (11) are warped in opposite directions due to the stress of the film or around the film, and the laser crystal substrate (11) may be cracked or peeled off.
However, in the method for manufacturing an optical element according to the fifth aspect, before the first composite substrate (21) and the laser crystal substrate (11) are bonded together, the first composite substrate (21) and the laser crystal substrate (11) are combined. Since the reflective mirror coating is applied to the film, it is possible to prevent the occurrence of the above-described cracking and peeling of the adhesive. The reason for this is that the laser crystal substrate (11) can be freely warped, so that it does not break and stress is not applied after bonding.

In a sixth aspect, the present invention is preformed so as to give a warp that cancels out the warp caused by applying the reflective mirror coating (11c) in the method of manufacturing an optical element according to the fifth aspect. Provided is a method for producing an optical element, characterized in that the reflection mirror coating (11c) is applied to the laser crystal substrate (11).
In the manufacturing method of the optical element according to the sixth aspect, the warp previously given by the warp by applying the reflecting mirror coating (11c) is canceled out, and the laser crystal substrate (11) becomes flat. Thereby, a 1st composite substrate (21) and a laser crystal substrate (11) can be adhere | attached suitably.
The first composite substrate (21) is also preferably preliminarily shaped so as to give a warp that cancels out the warp due to the reflection mirror coating (21c).

In a seventh aspect, the present invention relates to the optical axis direction side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A plate-like dummy material substrate is attached to at least one surface defined by the widthwise sides to form a first composite substrate (21), and a reflective mirror coating (21c) is applied to the first composite substrate (21). The first composite substrate (21) subjected to the reflection mirror coating (21c) is cut along a line (C) to be cut as a plurality of optical elements (9). A reflection mirror coating (11c) is applied to the other surface of the laser crystal substrate (11), which is the laser light emitting surface (11o), and the reflection mirror coating (line) is cut along a line (C) cut as a plurality of optical elements (9). 11c) laser crystal The plate (11) is cut, the laser light incident surface (12i) partitioned by the width direction side and the thickness direction side of the cut piece of the first composite substrate (21), and the laser crystal substrate (11) An optical element manufacturing method is provided, wherein an optical element (9) is obtained by pasting a cut piece to the surface having the laser light emitting surface (11o).
In the optical element manufacturing method according to the seventh aspect, the cut piece of the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is attached to the cut piece of the laser crystal substrate (11). Since the wavelength conversion crystal substrate and the dummy material substrate in the cut piece are attached to the cut piece of the laser crystal substrate (11) in the bonded area, the bonding operation is facilitated. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Further, since the first composite substrate (21) and the laser crystal substrate (11) having a large area are cut, a plurality of optical elements (9) can be manufactured together.

Furthermore, when a reflective mirror coating is applied to the second composite substrate (22) obtained by bonding the first composite substrate (21) and the laser crystal substrate (11), the temperature rise during film formation (200 in general film formation). The first composite substrate (21) and the laser crystal substrate (11) are warped in opposite directions due to the stress of the film or around the film, and the laser crystal substrate (11) may be cracked or peeled off.
However, in the optical element manufacturing method according to the seventh aspect, before the first composite substrate (21) and the laser crystal substrate (11) are bonded together, the first composite substrate (21) and the laser crystal substrate (11) are combined. Since a reflective mirror coating is applied to the film and cut and then bonded, the occurrence of the above-mentioned cracks and peeling of the adhesion can be prevented. The reason for this is that the laser crystal substrate (11) can be freely warped, so that it does not break and stress is not applied after bonding.

Here, the warp of the first composite substrate (21) due to the reflection mirror coating (21c) and the warp of the laser crystal substrate (11) due to the reflection mirror coating (11c) are opposite to the adhesive surface. Due to the direction, it may be difficult to bond with a large area.
However, in the optical element manufacturing method according to the seventh aspect, the first composite substrate (21) and the laser crystal substrate (11) are cut and bonded together. Since each bonded piece has a small bonding area, warpage is also small and bonding is facilitated.

In an eighth aspect, the present invention relates to the optical axis direction side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A dummy substrate of plate-like material is attached to at least one surface partitioned by the width direction side to form a first composite substrate (21), and the width direction side and the thickness direction of the first composite substrate (21) A laser light incident surface (12i) partitioned by a side and a plate-like body, the one surface of which is the laser light emission surface (11o), the surface having the laser light emission surface (11o) of the laser crystal substrate (11) Is applied to form a second composite substrate (22), the reflective mirror coating (11c, 21c) is applied to the second composite substrate (22) at a film forming temperature of 100 ° C. or lower, and then cut into a plurality of optical elements. (9) is obtained, and a method for producing an optical element is provided.
In the optical element manufacturing method according to the eighth aspect, the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is bonded to the laser crystal substrate (11). Since it is bonded to the laser crystal substrate (11) with the bonding area combined with the dummy material substrate, the bonding operation is much longer than the operation of bonding only the wavelength conversion crystal substrate to the laser crystal substrate (11). It becomes easy. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Moreover, a some optical element (9) can be manufactured collectively.

Furthermore, in a normal reflection mirror coating, the first composite substrate (21) and the laser crystal substrate (11) are reversed in the reverse direction due to a temperature rise during film formation (about 200 ° C. in general film formation) and film stress. On the other hand, the laser crystal substrate (11) may be cracked or peeled off.
However, in the manufacturing method of the optical element according to the eighth aspect, since the reflection mirror coating (11c, 21c) is applied at a film forming temperature of 100 ° C. or less, the laser crystal substrate (11) is not cracked or peeled off. Can be prevented. This is because warpage and stress are reduced due to low temperature.

In a ninth aspect, the present invention provides the optical element manufacturing method according to the eighth aspect, wherein the reflection mirror coating (11c, 21c) is applied using an ion assist method or an ion plating method. A method for manufacturing an optical element is provided.
In the method for manufacturing an optical element according to the ninth aspect, the reflective mirror coating (11c, 21c) can be applied at a film forming temperature of 100 ° C. or lower.

In a tenth aspect, the present invention provides the optical element manufacturing method according to the eighth aspect, wherein the reflection mirror coating (11c, 21c) is applied using an ion beam sputtering method. A manufacturing method is provided.
In the optical element manufacturing method according to the tenth aspect, the reflection mirror coating (11c, 21c) can be applied at a film forming temperature of 100 ° C. or lower.

In an eleventh aspect, the present invention provides the optical element manufacturing method according to the eighth aspect, wherein the reflection mirror coating (11c, 21c) is applied using an ECR sputtering method. Provide a method.
In the optical element manufacturing method according to the eleventh aspect, the reflection mirror coating (11c, 21c) can be applied at a film forming temperature of 100 ° C. or lower.

In a twelfth aspect, the present invention relates to the optical axis direction side of the wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side having an action length (L). A dummy substrate of plate-like material is attached to at least one surface partitioned by the width direction side to form a first composite substrate (21), and the width direction side and the thickness direction of the first composite substrate (21) A laser light incident surface (12i) partitioned by a side and a plate-like body, the one surface of which is the laser light emission surface (11o), the surface having the laser light emission surface (11o) of the laser crystal substrate (11) Are attached to form a second composite substrate (22), and the second composite substrate (22) is cut along a line (C) to be cut as a plurality of optical elements (9). (11c, 21c) to obtain a plurality of optical elements (9) It provides a method of manufacturing an optical element.
In the optical element manufacturing method according to the twelfth aspect, the first composite substrate (21) obtained by bonding the wavelength conversion crystal substrate and the dummy material substrate is bonded to the laser crystal substrate (11). Since it is bonded to the laser crystal substrate (11) with the bonding area combined with the dummy material substrate, the bonding operation is much longer than the operation of bonding only the wavelength conversion crystal substrate to the laser crystal substrate (11). It becomes easy. Therefore, the work efficiency of manufacture can be improved. Furthermore, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained. Moreover, a some optical element (9) can be manufactured collectively.

Furthermore, when a reflective mirror coating is applied to the second composite substrate (22), the first composite substrate (21) and the laser crystal substrate are caused by temperature rise during film formation (about 200 ° C. in general film formation) and film stress. In some cases, the laser crystal substrate (11) may be cracked or peeled off due to warping in the opposite direction to (11).
However, in the optical element manufacturing method according to the twelfth aspect, the second composite substrate (22) is cut along the line (C) to be cut as the plurality of optical elements (9), and then the reflection mirror coating is applied. The occurrence of the above-mentioned cracks and adhesion peeling can be prevented. This is because the laser crystal substrate (11) having a large area is cut and separated into pieces having a small area, so that warpage and stress in each piece are reduced.

In a thirteenth aspect, the present invention provides the optical element manufacturing method according to any one of the first to twelfth aspects, wherein the wavelength conversion crystal substrate is a substrate having a periodic domain-inverted structure. An optical element manufacturing method is provided.
In the method for manufacturing an optical element according to the thirteenth aspect, a substrate having a periodic polarization inversion structure is used. On the surface partitioned by the optical axis direction side and the width direction side of the substrate, the polarization of the periodic polarization inversion structure is provided. Since there is no restriction on the aspect ratio of the inversion period and the crystal thickness in the polarization direction, the bonding area between the wavelength conversion crystal substrate and the dummy material substrate can be increased, and this bonding operation becomes easy.

  According to the method for manufacturing an optical element of the present invention, manufacturing work efficiency can be improved and stable characteristics can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a flowchart illustrating the manufacturing procedure of the optical element according to the first embodiment.
In step S1, as shown in FIG. 2, the length L ′ of the side of the optical axis direction in the polarization inversion direction Dr, the width G in the width direction intersecting the polarization inversion direction Dr and the polarization direction Dp, and the thickness direction of the polarization direction Dp The wavelength conversion crystal large substrate 32 which is a plate-like body having a thickness d is prepared. The length L ′ is, for example, 6 mm, the width G is, for example, 6 mm, and the thickness d is, for example, 0.4 mm. Then, the process proceeds to step S3.
The wavelength conversion crystal large substrate 32 can be manufactured by the manufacturing method described in Patent Document 2, for example. That is, the periodic electrode 32b and the solid electrode 32c are formed on the opposing surfaces of the ferroelectric crystal large substrate 32a having a predetermined size, a voltage is applied between the electrodes, and the periodic polarization inversion structure is formed inside the ferroelectric crystal large substrate 32a. Form. The opposing direction of the electrodes is the polarization direction Dp, and the periodic pattern direction of the shape of the periodic electrode 32b is the polarization inversion direction Dr. The electrode may be left as it is or may be removed. When using an optical contact for bonding to the dummy material, it is preferable to remove it.

  The ferroelectric crystal large substrate 32a is, for example, a MgO-doped, stoichiometric composition or a lithium tantalate substrate close to the stoichiometric composition (MgO-doped stoichiometric lithium tantalate j substrate). The molar fraction Li2O / (Ta2O5 + Li2O) is 0.495 or more and less than 0.505.

  In step S2, as shown in FIG. 3A, a dummy material large substrate 13-1 that is a plate-like body having a length L ', a width G, and a thickness W is formed. Further, as shown in FIG. 3B, a dummy material large substrate 13-2 which is a plate-like body having a length L ', a width G, and a thickness w is formed. The thickness W is 1 mm, for example, and the thickness w is 0.5 mm, for example. Then, the process proceeds to step S3.

  The dummy material is preferably made of a material having a thermal conductivity larger than that of the glass so as to function suitably as a heat sink. Further, in order to suppress adverse effects when thermally expanded, it is preferable to use a material having a thermal expansion coefficient comparable to that of the laser crystal 1 and the wavelength conversion crystal 2. For example, an LT substrate, a CLT substrate, or a Cu substrate.

In step S3, as shown in FIG. 4, the wavelength conversion crystal large substrate 32 and the dummy material large substrate 13-1 are alternately bonded, the dummy material large substrate 13-2 is bonded to both ends, and the first composite large substrate is bonded. 21 ′ is created. The width Z of the first composite large substrate 21 ′ in the bonded direction is, for example, 7 mm.
As the bonding method, an adhesive may be used, or an optical contact may be used.

  In step S4, as shown in FIG. 5, the wavelength conversion crystal large substrate 32 is cut by a dicing apparatus for each predetermined action length L in the polarization inversion direction Dr (= optical axis direction), and the first composite substrate as shown in FIG. A plurality of 21 are obtained. C 'is a cutting line. The action length L is, for example, 2 mm.

  In step S5, two surfaces of the first composite substrate 21 facing the polarization inversion direction Dr are optically polished, and an AR film is formed if necessary. For example, an AR film for the fundamental wave is formed on the bonding surface side.

On the other hand, in step S8, a laser crystal large substrate having a predetermined thickness h is formed.
In step S9, the large laser crystal substrate is cut into a size matching the length G and width Z of the first composite substrate 21 to obtain the laser crystal substrate 11 as shown in FIG. For example, the thickness h of the laser crystal substrate 11 is 1 mm.
The laser crystal large substrate is, for example, a YAG crystal large substrate.

In step S10, optical polishing is performed on two surfaces of the laser crystal substrate 11 on which the laser light is incident or emitted, and an AR film is formed if necessary. For example, an AR film for the fundamental wave is formed on the bonding surface side.
Then, the process proceeds to step S14.

In step S14, as shown in FIG. 8, the surface of the first composite substrate 21 on which the AR film is formed, that is, the laser light incident surface 12i, and the surface of the laser crystal substrate 11 on which the AR film is formed, that is, the laser light emitting surface 11o Are bonded together to form the second composite substrate 22.
As the bonding method, an adhesive may be used, or an optical contact may be used.

In step S15a, as shown in FIG. 9, a cut K is made in the laser crystal substrate 11 of the second composite substrate 22 along a line C to be cut as a plurality of optical elements.
In step S16a, as shown in FIG. 10, the reflection mirror coating 11c is applied to the surface of the second composite substrate 22 where the cut K of the laser crystal substrate 11 is formed, and the reflection mirror is applied to the surface of the first composite substrate 21 on the opposite side. The coating 21c is applied.
In step S17, the second composite substrate 22 on which the reflection mirror coatings 21c and 11c are applied is cut along a line C to obtain a plurality of optical elements 9 as shown in FIG.

  In FIG. 11, an optical element 9 includes a laser crystal 1 that emits a fundamental laser beam when excited by excitation laser light Li from a semiconductor laser, and a wavelength conversion that emits a wavelength-converted laser beam Lo that is a harmonic of the fundamental laser beam. A crystal 2 and a dummy material 3 sandwiching the wavelength conversion crystal 2 in a sandwich shape are provided.

According to the first embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 are bonded to the laser crystal substrate 11 in a combined area, the bonding operation is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the laser crystal substrate 11 is separated into sections having a small area by the notch K, the warp and stress caused by applying the reflection mirror coatings 11c and 21c are reduced in each section, and the laser crystal substrate 11 is cracked and bonded. Occurrence of peeling can be prevented.

The above-described first embodiment and the embodiments described later may be modified as follows.
In step S5, the first composite substrate 21 is polished, and an AR film is formed on the bonding surface.
In step S10, the laser crystal substrate 11 is polished, and an AR film is formed on the bonding surface.
In step S14, the first composite substrate 21 and the laser crystal substrate 11 are bonded together to create a temporary second composite substrate, and the laser incident surface of the temporary second composite substrate (opposite to the laser light emitting surface 11o of the laser crystal substrate 11). Side surface) and a laser emission surface (surface opposite to the laser light incident surface 12i in the first composite substrate 21) are subjected to optical polishing, and an HR film is formed to form the second composite substrate 22. .
According to this modification, the optical element 9 having good parallel plane accuracy can be obtained by forming the HR plane after the first composite substrate 21 and the laser crystal substrate 11 are bonded together.

  Further, after setting the length L ′ of the wavelength conversion crystal large substrate 32 = the working length L and the length L ′ = the working length L of the dummy material large substrates 13-1, 13-2, these may be bonded together. Good.

FIG. 12 is a flowchart illustrating the manufacturing procedure of the optical element according to the second embodiment.
Steps S1 to S5, S8 to S10, and S14 are the same as those in the first embodiment.
After step S14, the process proceeds to step S15b.

  In step S15b, as shown in FIG. 13, a mask M is attached to shield the belt-like portion along the line C to be cut as a plurality of optical elements on the laser incident surface and the laser emitting surface of the second composite substrate 22. The mask M is a metal plate, for example.

In step S16b, the reflective mirror coatings 11c and 21c are applied to the surface of the second composite substrate 22 to which the mask M is attached. Then, the mask M is removed. FIG. 14 shows the second composite substrate 22 from which the mask M is removed after the reflection mirror coatings 11c and 21c are applied.
In step S17, the second composite substrate 22 to which the reflection mirror coatings 11c and 21c are applied is cut along a line C, and a plurality of optical elements 9 as shown in FIG. 15 are obtained.

The mask M may be a metal plate, a photoregistry or polyimide.
When the mask M is a metal plate, the mask M is removed after the reflection mirror coating. Further, when the mask M is a photo-registry or polyimide, the second composite substrate 22 is removed by a lift-off method before or after cutting along the line C.

According to the second embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 are bonded to the laser crystal substrate 11 in a combined area, the bonding operation is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the reflection mirror coatings 11c and 21c are separated into smaller sections by the mask M, warpage and stress due to the application of the reflection mirror coatings 11c and 21c are reduced in each section, and the laser crystal substrate 11 is not cracked. It is possible to prevent the occurrence of adhesion peeling.

FIG. 16 is a flowchart illustrating the manufacturing procedure of the optical element according to the third embodiment.
Steps S1 to S5 are the same as those in the first embodiment.
In step S6, as shown in FIG. 17, the reflection mirror coating 21c is applied to the surface of the first composite substrate 21 opposite to the laser light incident surface 12i. Then, the process proceeds to step S14.

Steps S8 to S10 are the same as those in the first embodiment.
In step S11, as shown in FIG. 18, a reflection mirror coating 11c is applied to the surface of the laser crystal substrate 11 opposite to the laser light emitting surface 11o. Then, the process proceeds to step S14.

In step S14, as shown in FIG. 19, the laser light incident surface 12i of the first composite substrate 21 and the laser light emission surface 11o of the laser crystal substrate 11 are bonded together to form the second composite substrate 22.
In step S17, the second composite substrate 22 to which the reflection mirror coatings 21c and 11c are applied is cut along a line C, and a plurality of optical elements 9 as shown in FIG. 20 are obtained.

According to the third embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 are bonded to the laser crystal substrate 11 in a combined area, the bonding operation is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the reflection mirror coatings 21c and 11c are individually applied to the first composite substrate 21 and the laser crystal substrate 11, they can be freely warped and are not cracked. Moreover, since it does not warp after bonding, it is possible to prevent the peeling of the bonding.

The third embodiment may be modified as follows.
In step S5, as shown in FIG. 21, the first composite substrate 21 is polished and shaped in advance so as to give a warp that offsets the warp caused by applying the reflection mirror coating 21c.
In step S10, as shown in FIG. 22, the laser crystal substrate 11 is polished and shaped in advance so as to give a warp that offsets the warp caused by applying the reflection mirror coating 11c.
According to this modification, the warp previously given is canceled by the warp by applying the reflection mirror coatings 21c and 11c, and the first composite substrate 21 and the laser crystal substrate 11 become flat. The crystal substrate 11 can be suitably bonded.

FIG. 23 is a flowchart illustrating the manufacturing procedure of the optical element according to the fourth embodiment.
Steps S1 to S6 are the same as in the third embodiment.
After step S6, the process proceeds to step S7.

  In step S7, as shown in FIG. 24, the second composite substrate 22 on which the reflection mirror coating 21c is applied is cut along the line C to obtain a plurality of cut pieces as shown in FIG. The cut piece includes a wavelength conversion crystal 2 and a dummy material 3 sandwiching the wavelength conversion crystal 2 in a sandwich shape. After step S7, the process proceeds to step S13.

Steps S8 to S11 are the same as in the third embodiment.
After step S11, the process proceeds to step S12.

  In step S12, the laser crystal substrate 11 on which the reflection mirror coating 11c is applied as shown in FIG. 26 is cut along line C to obtain a plurality of cut pieces as shown in FIG. After step S12, the process proceeds to step S13.

  In step S13, the cut piece of FIG. 25 and the cut piece of FIG. 27 are bonded to obtain the optical element 9 as shown in FIG.

According to the fourth embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the area of the laser light incident surface 2i and the area of the dummy material portion 3d in the cut piece of FIG. 25 are pasted to the cut piece of FIG. 27, the bonding work is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the reflection mirror coatings 21c and 11c are independently applied to the first composite substrate 21 and the laser crystal substrate 11, each can be freely warped and not cracked. Moreover, since it adhere | attaches after cut | disconnecting to a cut piece with a small area, the amount of curvature in each cut piece becomes small, and it can bond suitably. Furthermore, since it does not warp after bonding, it is possible to prevent the peeling of the bonding.

FIG. 28 is a flowchart illustrating the manufacturing procedure of the optical element according to the fifth embodiment.
Steps S1 to S5, S8 to S10, and S14 are the same as those in the first embodiment.
After step S14, the process proceeds to step S16c.

In step S16c, the reflective mirror coatings 11c and 21c are applied to the second composite substrate 22 at a film forming temperature of 100 ° C. or lower. For example, if an ion assist method, an ion plating method, an ion beam sputtering method, or an ECR sputtering method is used, the reflection mirror coatings 11c and 21c can be applied at a film forming temperature of 100 ° C. or less.
In step S17, the second composite substrate 22 on which the reflection mirror coatings 11c and 21c are applied is cut to obtain a plurality of optical elements 9.

According to the fifth embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 are bonded to the laser crystal substrate 11 in a combined area, the bonding operation is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the reflection mirror coatings 11c and 21c are applied at a film forming temperature of 100 ° C. or lower, warpage and stress are reduced, and therefore, the generation of cracks and peeling of the laser crystal substrate 11 can be prevented.

FIG. 29 is a flowchart illustrating the manufacturing procedure of the optical element according to the sixth embodiment.
Steps S1 to S5, S8 to S10, and S14 are the same as those in the first embodiment.
After step S14, the process proceeds to step S17.

  In step S17, as shown in FIG. 30, the second composite substrate 22 is cut along line C to obtain a plurality of cut pieces as shown in FIG.

  In step S18, a reflecting mirror coating is applied to the cut piece of the second composite substrate 22 to obtain an optical element 9 as shown in FIG.

According to the sixth embodiment, the following effects can be obtained.
(1) Since the bonding area of the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 is large (for example, 6 mm × 7 mm), the bonding operation becomes easy. Therefore, the work efficiency of manufacture can be improved. In addition, since it can be bonded with a stable quality, there is no problem that the characteristics differ depending on the location within the bonded surface or the characteristics vary between optical elements, and stable characteristics can be obtained.
(2) Since the first composite large substrate 21 ′ is cut with the action length L with respect to the side in the optical axis direction, the alignment with respect to the optical axis does not vary and stable characteristics can be obtained.
(3) Since the wavelength conversion crystal large substrate 32 and the dummy material large substrates 13-1 and 13-2 are bonded to the laser crystal substrate 11 in a combined area, the bonding operation is facilitated.
(4) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.
(5) A plurality of optical elements 9 can be manufactured together.
(6) Since the reflecting mirror coatings 21c and 11c are applied after cutting into cut pieces having a small area, warpage and stress in each cut piece are reduced, and generation of cracks and peeling of the adhesive can be prevented.

(1) As the wavelength conversion crystal large substrate 32, an LT substrate or LN substrate having a periodic polarization structure therein, an LT substrate or LN substrate doped with MgO, or a KTP substrate can also be used.
(2) As the dummy material large substrates 13-1 and 13-2, the same material as the wavelength conversion crystal 2 (periodic polarization inversion structure is not required), quartz glass, BK-7, or the like can be used.
(3) The dummy substrate 3 may be bonded to only one side of the wavelength conversion crystal 2.

  The method for producing an optical element of the present invention can be used for, for example, a semiconductor excitation solid-state laser using an SHG wavelength conversion technique.

FIG. 3 is a flowchart showing a manufacturing procedure of the optical element according to Example 1. It is a perspective view which shows a wavelength conversion crystal large substrate. It is a perspective view which shows a dummy material large board | substrate. It is a perspective view which shows a 1st composite large board | substrate. It is a perspective view which shows the cutting | disconnection of a 1st composite large board | substrate. It is a perspective view which shows a 1st composite substrate. It is a perspective view which shows the bonding process of a 1st composite substrate and a laser crystal substrate. It is a perspective view which shows a 2nd composite substrate. It is a perspective view which shows the process of notching a 2nd composite substrate. It is a perspective view which shows the process of giving a reflective mirror coating to the 2nd composite substrate which put the notch. 1 is a perspective view showing an optical element according to Example 1. FIG. FIG. 6 is a flowchart showing a manufacturing procedure of an optical element according to Example 2. It is a perspective view which shows the process of attaching a mask to a 2nd composite substrate. It is a perspective view which shows the 2nd composite substrate which removed the mask after giving a reflective mirror coating. 6 is a perspective view showing an optical element according to Example 2. FIG. FIG. 6 is a flowchart showing a manufacturing procedure of an optical element according to Example 3. It is a perspective view which shows the 1st composite substrate which gave the reflective mirror coating. It is a perspective view which shows the laser crystal substrate which gave the reflective mirror coating. It is a perspective view which shows the bonding process of the 1st composite substrate which gave the reflective mirror coating, and the laser crystal substrate which gave the reflective mirror coating. 10 is a perspective view showing an optical element according to Example 3. FIG. It is a perspective view which shows the 1st composite substrate previously shape | molded so that curvature might be given. It is a perspective view which shows the laser crystal substrate previously shape | molded so that curvature might be given. FIG. 6 is a flowchart showing a manufacturing procedure of an optical element according to Example 4. It is a perspective view which shows the 1st composite substrate which gave the reflective mirror coating. It is a perspective view which shows the cut piece of the 1st composite substrate which gave the reflective mirror coating. It is a perspective view which shows the laser crystal substrate which gave the reflective mirror coating. It is a perspective view which shows the cut piece of the laser crystal substrate which gave the reflective mirror coating. FIG. 10 is a flowchart showing a manufacturing procedure of an optical element according to Example 5. FIG. 10 is a flowchart showing a manufacturing procedure of an optical element according to Example 6. It is a perspective view which shows the cutting process of a 2nd composite substrate. It is a perspective view which shows the cut piece of a 2nd composite substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser crystal 2 Wavelength conversion crystal 3 Dummy material 9 Optical element 11 Laser crystal substrate 11c, 21c Reflective mirror coating 13-1, 13-2 Dummy material large substrate 21 1st composite substrate 21 '1st composite large substrate 22 2nd composite Substrate 32 Wavelength conversion crystal large substrate C, C ′ Cutting line Dp Polarization direction Dr Polarization inversion direction K Notch L Action length M Mask

Claims (13)

The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and the laser light incident surface defined by the width direction side and the thickness direction side of the first composite substrate (21) (12i) and the surface of the laser crystal substrate (11) having the laser light emitting surface (11o), the one surface of which is a laser light emitting surface (11o), are attached to the second composite substrate ( 22), and after making a cut (K) in the laser crystal substrate (11) of the second composite substrate (22) along a line (C) to be cut as a plurality of optical elements (9), a reflection mirror coating (11c, 21c), then cut along the line (C) Method of manufacturing an optical element, characterized in that to obtain an optical element (9).
The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and the laser light incident surface defined by the width direction side and the thickness direction side of the first composite substrate (21) (12i) and the surface of the laser crystal substrate (11) having the laser light emitting surface (11o), the one surface of which is a laser light emitting surface (11o), are attached to the second composite substrate ( 22), a mask (M) is attached to the laser crystal substrate (11) of the second composite substrate (22) along a line (C) to be cut as a plurality of optical elements (9), and then a reflective mirror coating is applied. (11c, 21c), then cut along the line (C) Method of manufacturing an optical element, characterized in that to obtain an optical element (9). The method of manufacturing an optical element according to claim 2, wherein the mask (M) is a metal plate. 3. The optical element manufacturing method according to claim 2, wherein the mask (M) is a photo-registry or polyimide, and is removed by a lift-off method before or after cutting along the line (C). Device manufacturing method.
The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and a reflection mirror coating (21c) is applied to the first composite substrate (21). The width | variety of the 1st composite substrate (21) which gave the reflective mirror coating (11c) to the other surface of the laser crystal substrate (11) whose one surface is a laser beam emission surface (11o), and gave the reflective mirror coating (21c) A laser light incident surface (12i) partitioned by a direction side and a thickness direction side and a surface on which the laser light emitting surface (11o) of the laser crystal substrate (11) provided with the reflection mirror coating (11c) is provided. The second composite substrate ( 2), a plurality of optical elements (9) are obtained by cutting the second composite substrate (22) along a line (C) to be cut as a plurality of optical elements (9). Production method. 6. The method of manufacturing an optical element according to claim 5, wherein the reflection is applied to the laser crystal substrate (11) that has been shaped in advance so as to give a warp that cancels the warp caused by applying the reflective mirror coating (11c). A method for producing an optical element, comprising applying a mirror coating (11c).
The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and the first composite substrate (21) is provided with a reflective mirror coating (21c) and cut into a plurality of optical elements (9). The first composite substrate (21) provided with the reflection mirror coating (21c) is cut along the line (C) to be cut, and on the other hand, the laser is a plate-like body, one surface of which is the laser light emission surface (11o) A laser crystal substrate (11) having a reflection mirror coating (11c) applied to the other surface of the crystal substrate (11) and the reflection mirror coating (11c) being applied along a line (C) cut as a plurality of optical elements (9). ) The laser light incident surface (12i) partitioned by the width direction side and the thickness direction side of the cut piece of one composite substrate (21) and the laser light emission surface (11o) of the cut piece of the laser crystal substrate (11) ) To obtain an optical element (9).
The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and the laser light incident surface defined by the width direction side and the thickness direction side of the first composite substrate (21) (12i) and the surface of the laser crystal substrate (11) having the laser light emitting surface (11o), the one surface of which is a laser light emitting surface (11o), are attached to the second composite substrate ( 22), reflecting mirror coating (11c, 21c) is applied to the second composite substrate (22) at a film forming temperature of 100 ° C. or lower, and then cut to obtain a plurality of optical elements (9). A method for manufacturing an optical element. 9. The method of manufacturing an optical element according to claim 8, wherein the reflection mirror coating (11c, 21c) is applied using an ion assist method or an ion plating method. 9. The method of manufacturing an optical element according to claim 8, wherein the reflection mirror coating (11c, 21c) is applied using an ion beam sputtering method. 9. The method of manufacturing an optical element according to claim 8, wherein the reflection mirror coating (11c, 21c) is applied using an ECR sputtering method.
The wavelength conversion crystal substrate, which is a plate-like body having an optical axis direction side, a width direction side, and a thickness direction side of the length of the working length (L), is defined by at least the optical axis direction side and the width direction side. A plate-like dummy material substrate is attached to one surface to form a first composite substrate (21), and the laser light incident surface defined by the width direction side and the thickness direction side of the first composite substrate (21) (12i) and the surface of the laser crystal substrate (11) having the laser light emitting surface (11o), the one surface of which is a laser light emitting surface (11o), are attached to the second composite substrate ( 22), the second composite substrate (22) is cut along a line (C) to be cut as a plurality of optical elements (9), and a reflecting mirror coating (11c, 21c) is applied to each of the cut pieces. A method for producing an optical element, comprising obtaining the optical element (9).
13. The method of manufacturing an optical element according to claim 1, wherein the wavelength conversion crystal substrate is a substrate having a periodically poled structure.

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