JP5428132B2 - Optical element manufacturing method and optical element - Google Patents

Description

  The present invention relates to an optical element manufacturing method and an optical element, and more particularly, to an optical element manufacturing method and an optical element that can collectively manufacture a plurality of optical elements whose end surfaces are convex.

A method of manufacturing a plurality of LD-pumped solid-state laser elements by forming a non-reflective coating film and a mirror film on a large-sized laser crystal substrate and then cutting and separating is known (see Patent Document 1).
Further, there is known a laser resonator in which a mirror film is formed after a surface opposite to a laser light incident surface of a laser crystal is formed as a convex surface (see Patent Documents 2 and 3).
Japanese Patent Publication No. 6-58982 JP-A-5-173003 JP-A-6-275891

In the conventional method for manufacturing an LD-pumped solid-state laser element, a plurality of optical elements can be manufactured in a lump, but each optical element has a flat end surface and does not become a convex surface. Further, when cutting and separating into a plurality of parts, there is a possibility that the surface on which the mirror film is applied is damaged.
On the other hand, in the conventional laser resonator, the end face of the optical element is convex, but a plurality of optical elements cannot be manufactured in a lump.
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical element manufacturing method and an optical element that can collectively manufacture a plurality of optical elements whose end surfaces are convex.

In a first aspect, the present invention provides a groove forming step for forming a groove in the surface of a plate-like body containing an optical material, a polishing step for polishing the surface so as to cause surface sag at the edge portion of the groove, And a separation step of obtaining a plurality of optical elements by cutting and separating with a groove.
In general, surface sagging refers to a phenomenon in which flatness is significantly deteriorated at the edge portion rather than the center portion of the object to be polished when the flat surface is polished. This is because when polishing the surface, the amount of polishing near the edge is greater than the amount of polishing away from the edge, or when the polishing pad is used, the polishing pad is restored at the edge. Occurs.
Although the sagging is a phenomenon that should be avoided originally, the optical element manufacturing method according to the first aspect uses this in reverse. That is, a groove is formed in the surface before polishing the surface of the plate-like body containing the optical material. When such a groove is present, surface sagging can be caused in which the amount of polishing near the edge of the groove is greater than the amount of polishing at a distant portion. And the area | region enclosed by the groove | channel becomes a convex surface by surface sagging. Therefore, if it cuts and isolate | separates with a groove | channel after grinding | polishing, the some optical element whose end surface is convex can be obtained collectively. In this case, since the grooves are formed in advance, it is possible to avoid damaging the polished surface when cutting and separating.

In a second aspect, the present invention is characterized in that, in the optical element manufacturing method according to the first aspect, in the groove forming step, a square or substantially square lattice shape or a plurality of circular shapes are cut. A method for manufacturing an optical element is provided.
In the method for manufacturing an optical element according to the second aspect, since a cut is made in a square or substantially square lattice shape or a plurality of circular shapes, a symmetrical convex surface can be formed in the vicinity of the optical axis.

In a third aspect, the present invention provides the method for manufacturing an optical element according to the first or second aspect, wherein in the polishing step, the surface is polished using a resilient polishing pad. A method for manufacturing an optical element is provided.
In the method for manufacturing an optical element according to the third aspect, surface sagging can be preferably caused by polishing the surface using a resilient polishing pad. The elastic polishing pad as used herein means a polishing pad having a cotton cloth, chemical fiber, or foam layer on the surface.

In a fourth aspect, the present invention provides the method for producing an optical element according to any one of the first to third aspects, wherein the optical material is glass, a laser crystal, or a wavelength conversion crystal. A method for manufacturing an optical element is provided.
In the optical element manufacturing method according to the fourth aspect, a lens having a convex end surface, a solid-state laser element, and a wavelength conversion element can be obtained.

In a fifth aspect, the present invention is a plate-like body, and one surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12) whose one surface is the laser light incident surface (12i). Alternatively, a first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to the one surface (12a) and the one surface (12a) opposite thereto to form a first composite substrate (21), and the first composite A notch step of making incisions (K) in a lattice shape or a plurality of circular shapes on the surface of the substrate (21) opposite to the laser light incident surface (12i), and surface sagging at the edge portion of the notches (K). There is provided a method for manufacturing an optical element, comprising: a polishing step for polishing the surface so as to wake up; and a separation step for cutting and separating by the notch (K) to obtain a plurality of optical elements (9).
In the method for manufacturing an optical element according to the fifth aspect, a notch (K) is made in the surface before polishing the surface of the first composite substrate (21). If there is such a cut (K), surface sagging can occur due to reasons such as the amount of polishing near the edge of the cut (K) being greater than the amount of polishing at a distant portion. And the area | region enclosed by the notch | incision (K) becomes a convex surface by surface sagging. Therefore, if it cut | disconnects by cutting | disconnection (K) after grinding | polishing, the several wavelength conversion element (9) by which the end surface became the convex surface can be obtained collectively.

In a sixth aspect, the present invention is a plate-like body, and one surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12) whose one surface is the laser light incident surface (12i). Alternatively, a first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to the one surface (12a) and the one surface (12a) opposite thereto to form a first composite substrate (21), and the first composite A notch step of making incisions (K) in a lattice shape or a plurality of circular shapes on the surface of the substrate (21) opposite to the laser light incident surface (12i), and surface sagging at the edge portion of the notches (K). A polishing step for polishing the surface so as to occur, a surface of the first composite substrate (21) with the laser light incident surface (12i) and a plate-like body, one surface of which is a laser light emitting surface (11o) Of a laser crystal substrate (11) A second composite substrate manufacturing step in which the laser light emitting surface (11o) is attached to the second composite substrate (22), and a plurality of optical elements (10) cut and separated by the cut (K). And a separation step for obtaining an optical element.
In the method for manufacturing an optical element according to the sixth aspect, a cut (K) is made in the surface before polishing the surface of the first composite substrate (21). If there is such a cut (K), surface sag can occur from the edge portion of the cut (K). And the area | region enclosed by the notch | incision (K) becomes a convex surface by surface sagging. Therefore, if this is attached to the laser crystal substrate (11) and then cut and separated by cutting (K), a plurality of optical elements (10) whose end surfaces are convex can be obtained in a lump.

In a seventh aspect, the present invention is a plate-like body, and one surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12) whose one surface is the laser light incident surface (12i). Alternatively, a first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to the one surface (12a) and the one surface (12a) opposite thereto to form a first composite substrate (21), and the first composite The laser light emitting surface (11o) of the laser crystal substrate (11), which is a plate-like body and a surface having the laser light incident surface (12i) of the substrate (21), and one surface thereof is the laser light emitting surface (11o). A second composite substrate manufacturing step of attaching a surface to the second composite substrate (22), and a surface of the second composite substrate (22) opposite to the attachment surface of the laser crystal substrate (11). Cut into a grid or multiple circles (K An incision step for cutting, a polishing step for polishing the surface so as to cause surface sag at the edge of the incision (K), and separation to obtain a plurality of optical elements (10) by cutting and separating at the incision (K) And a method for manufacturing an optical element.
In the method for manufacturing an optical element according to the seventh aspect, a notch (K) is made in the surface before polishing the surface of the second composite substrate (22). If there is such a cut (K), surface sag can occur from the edge portion of the cut (K). And the area | region enclosed by the notch | incision (K) becomes a convex surface by surface sagging. Therefore, if it cut-separates by cutting (K), the several optical element (10) by which the end surface became the convex surface can be obtained collectively.

In an eighth aspect, the present invention provides a method for producing an optical element according to the sixth or seventh aspect, wherein a spacer (5) is provided between the first composite substrate (3) and the laser crystal substrate (11). The first composite substrate (3), the spacer (5), the spacer (5), and the laser crystal substrate (11) are bonded with an adhesive having the same or substantially the same refractive index as that of the spacer (5). An optical element manufacturing method is provided.
If only the adhesive is applied, the thickness of the adhesive is almost determined and an etalon effect may occur.
Therefore, in the optical element manufacturing method according to the eighth aspect, the optical path length can be adjusted by sandwiching the spacer (5), and the etalon effect can be controlled.

In a ninth aspect, the present invention relates to a wavelength conversion crystal (2), which is a plate-like body and one surface of which is a laser light incident surface (2i), and a plate-like body, the one surface (3e) of which has the wavelength. A dummy material (3) affixed to one surface (2a) other than the laser light incident surface (2i) of the conversion crystal (2), and a laser light emission surface (2o) of the wavelength conversion crystal (2) An optical element (9) characterized in that is a convex surface.
Since the optical element (9) according to the ninth aspect has a structure in which the dummy material (3) is attached to the wavelength conversion crystal (2), the heat dissipation function of the dummy material (3) can be used and the entire structure can be used. Can be downsized. Further, since the laser light emission surface (2o) of the wavelength conversion crystal (2) is a convex surface, a laser resonator capable of obtaining a stable single resonator mode can be configured by applying a laser coating.

In a tenth aspect, the present invention relates to a laser crystal (1), which is a plate-like body, one surface of which is a laser light emitting surface (1o), and a plate-like body, the one surface of which is a laser light incident surface (2i). ) And the laser beam incident surface (2i) is affixed to a part of the laser beam emitting surface (1o), and a plate-like body whose one surface (3d) is the A dummy attached to a part of the laser light emitting surface (1o) and another surface (3e) attached to one surface (2a) other than the laser light incident surface (2i) of the wavelength conversion crystal (2). There is provided an optical element (10) comprising a material (3), wherein the laser beam emission surface (2o) of the wavelength conversion crystal (2) is a convex surface.
In the optical element (10) according to the tenth aspect, it is possible to adopt a manufacturing method in which the wavelength conversion crystal (2) and the dummy material (3) are bonded together and then bonded to the laser crystal (1). Here, since there is no restriction on the aspect ratio of the polarization reversal period and the crystal thickness in the polarization direction of the periodic polarization reversal structure on one surface (2a) other than the laser light incident surface (2i), the wavelength conversion crystal (2) and The bonding area of the dummy material (3) can be increased, and this bonding operation is easy. In addition, the product obtained by bonding the wavelength conversion crystal (2) and the dummy material (3) is bonded to the laser crystal (1), but the bonded area is the same as the wavelength conversion crystal (2) and the dummy material (3). Therefore, the bonding operation becomes much easier than the operation of bonding only the wavelength conversion crystal (2) to the laser crystal (1). 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. In addition, since the laser light emission surface (2o) of the wavelength conversion crystal (2) is a convex surface, laser resonance can provide a stable single resonator mode by applying a laser coating on both surfaces of the optical element (10). The device can be composed of a single element.

In an eleventh aspect, the present invention provides the optical element (10) according to the tenth aspect, wherein the laser crystal (1) includes the wavelength conversion crystal (2) and the dummy material (3) substantially the same as an adhesive. Provided is an optical element (10) characterized in that the optical element (10) is pasted with the adhesive with a refractive index spacer (5) interposed therebetween.
If only the adhesive is used, the thickness of the adhesive is almost determined, and an etalon effect may occur.
Therefore, in the optical element (10) according to the eleventh aspect, the optical path length is adjusted with the spacer (5) interposed therebetween to control the etalon effect.

In a twelfth aspect, the present invention provides an optical element (10) according to the tenth or eleventh aspect, wherein the wavelength conversion crystal (2) and the dummy material (3) are optically connected to the laser crystal (1). Provided is an optical element (10) characterized by being attached by contact.
In the optical element (10) according to the twelfth aspect, since the optical contact is used, the adhesive layer is eliminated, so that the etalon effect does not occur.

In a thirteenth aspect, the present invention provides the optical element (9, 10) according to any one of the ninth to twelfth aspects, wherein the wavelength conversion crystal (2) has a periodic polarization inversion structure therein. Provided is an optical element (9, 10) characterized by being a ferroelectric crystal.
In the optical element (9, 10) according to the thirteenth aspect, since the ferroelectric crystal having the periodic polarization inversion structure is used as the wavelength conversion crystal (2), the polarization inversion period of the periodic polarization inversion structure is Limited by the aspect ratio of the crystal thickness in the polarization direction. Therefore, the present invention is particularly useful.

According to a fourteenth aspect, the present invention provides the optical element (9, 10) according to the thirteenth aspect, wherein the ferroelectric crystal is a stoichiometric composition or a lithium tantalate close to the stoichiometric composition. An optical element (9, 10) is provided.
In the optical element (9, 10) according to the fourteenth aspect, since the lithium tantalate close to the stoichiometric composition (stoichiometry) or the stoichiometric composition is used, it is easy to form a periodically poled structure.

In a fifteenth aspect, the present invention provides the optical element (9, 10) according to the fourteenth aspect, wherein the lithium tantalate molar fraction Li2O / (Ta2O5 + Li2O) is 0.490 or more and less than 0.500. An optical element (9, 10) is provided.
In the optical element (9, 10) according to the fifteenth aspect, since the lithium tantalate having a molar fraction Li2O / (Ta2O5 + Li2O) of 0.490 or more and less than 0.500 is used, it is easy to form a periodically poled structure. Become.

In a sixteenth aspect, the present invention provides the optical element (9, 10) according to the fourteenth or fifteenth aspect, wherein the lithium tantalate is doped with at least one of Mg, Zn, Sc, and In An optical element (9, 10) is provided.
In the optical element (9, 10) according to the sixteenth aspect, it is easy to form a periodic domain-inverted structure.

In a seventeenth aspect, the present invention provides the optical element (9, 10) according to any one of the ninth to sixteenth aspects, wherein the thermal conductivity of the dummy material (3) is greater than the thermal conductivity of glass. An optical element (9, 10) is also provided.
In the optical element (9, 10) according to the seventeenth aspect, the dummy material (3) preferably functions as a heat sink.

In an eighteenth aspect, the present invention relates to the optical element (9, 10) according to any one of the ninth to seventeenth aspects, wherein the wavelength conversion crystal (2) and the dummy material (3) are bonded to each other. Provided is an optical element (9, 10) that is affixed by (7).
In the optical element (9, 10) according to the eighteenth aspect, since the adhesive is used, the operation becomes easier than in the case where the optical contact (7) is used.

  According to the optical element manufacturing method and the optical element of the present invention, it is possible to manufacture a plurality of optical elements whose end surfaces are convex.

  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 perspective view illustrating an optical element 9 according to the first embodiment.
The optical element 9 is attached to the wavelength conversion crystal 2 so as to sandwich the wavelength conversion crystal 2 that sandwiches the wavelength conversion crystal 2 that emits the wavelength conversion laser light Lo (SHG light) that is a harmonic of the fundamental laser light Lm. The dummy material 3 is provided, and the laser light incident surface 2i of the wavelength conversion crystal 2 and one surface 3d of the dummy material 3 are on the same plane.
The laser beam emission surface 2o of the wavelength conversion laser beam Lo of the optical element 9 is a convex surface.

FIG. 2 is an exploded perspective view of the optical element 9.
The surface 3e of the plate-like dummy material 3 is attached to the surface 2a of the plate-like wavelength conversion crystal 2 that is not the laser light incident surface 2i.

FIG. 3 is a flowchart showing the manufacturing procedure of the optical element 9.
In step S1, a wavelength conversion crystal large substrate 32 as shown in FIG. 4 is produced.
The wavelength conversion crystal large substrate 32 can be manufactured by, for example, a manufacturing method described in JP-A-2005-208197. 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. If optical contact is used for bonding with the dummy material, 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 0.49 or more and less than 0.5.

In step S2, the wavelength conversion crystal large substrate 32 is cut with a dicing device so that the width of the polarization reversal direction Dr becomes a predetermined working length L, thereby obtaining a plurality of wavelength conversion crystal substrates 12 as shown in FIG. For example, the action length L of the wavelength conversion crystal substrate 12 is 2 mm, the thickness d is 0.4 mm, and the length G in the direction intersecting the polarization direction Dp and the polarization inversion direction Dr is 6 mm.
Then, the process proceeds to step S5.

On the other hand, in step S3, a dummy material large substrate having a thickness W and a dummy material large substrate having a thickness w are manufactured.
In step S4, the dummy material large substrate is cut into a size that matches the working length L and length G of the wavelength conversion crystal substrate 12 to obtain a plurality of dummy material substrates 13-1 and 13-2 as shown in FIG. For example, the thickness W of the dummy material substrate 13-1 is 1 mm, and the thickness w of the dummy material substrate 13-2 is 0.5 mm.
Then, the process proceeds to step S5.

  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 or a CLT substrate.

In step S5, as shown in FIG. 7, the wavelength conversion crystal substrate 12 and the dummy material substrate 13-1 are alternately bonded, and the dummy material substrate 13-2 is bonded to both ends, thereby producing the first composite substrate 21. . The width Z of the first composite 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 S6, as shown in FIG. 8, the surface of the first composite substrate 21 is cut into a square or substantially square lattice K to form a first composite substrate 21 ′.
In step S7, the surface of the first composite substrate 21 ′ is polished using an abrasive and an elastic polishing pad so as to cause surface sag from the edge portion of the cut K. Thereby, as shown in FIG. 9, each surface surrounded by the cut K becomes a convex surface. This is referred to as a first composite substrate 21 ″.

  In step S8, two surfaces of the first composite substrate 21 ″ facing the polarization reversal direction Dr are optically polished to form a necessary AR film or HR film. For example, an AR film for the fundamental wave is formed on one of the two surfaces. The HR film is formed on the other side.

  In step S9, the first composite substrate 21 "is cut along the cutting line C as shown in FIG.

According to the first embodiment, the following effects can be obtained.
(1) A plurality of optical elements 9 whose end surfaces are convex can be manufactured together.
(2) Since the bonded areas of the wavelength conversion crystal substrate 12 and the dummy material substrate 13-1 and the wavelength conversion crystal substrate 12 and the dummy material substrate 13-2 are large (for example, 2 mm × 7 mm), the bonding operation is facilitated. 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.
(3) If a material having better thermal conductivity than glass is used as the dummy material 3, it functions suitably as a heat sink.

FIG. 11 is a perspective view illustrating the optical element 10 according to the second embodiment.
The optical element 10 includes a laser crystal 1 that emits a fundamental laser beam by being excited by excitation laser light Li from a semiconductor laser, and a wavelength conversion crystal 2 that emits a wavelength conversion laser beam Lo that is a harmonic of the fundamental laser beam. And a dummy material 3 sandwiching the wavelength conversion crystal 2 in a sandwich shape.
The laser beam emission surface 2o of the wavelength conversion laser beam Lo of the optical element 10 is a convex surface.

FIG. 12 is an exploded perspective view of the optical element 10.
The laser beam incident surface 2i of the plate-shaped wavelength conversion crystal 2 is attached to a part of the laser beam emitting surface 1o of the plate-shaped laser crystal 1. Further, one surface 3d of the plate-like dummy material 3 is attached to another part of the laser light emitting surface 1o of the laser crystal 1, and the other surface 3e of the dummy material 3 is incident on the laser light of the wavelength conversion crystal 2. Affixed to one surface 2a other than the surface 2i.

FIG. 13 is a flowchart showing the manufacturing procedure of the optical element 10.
Steps S1 to S8 are the same as in the first embodiment. After step S8, the process proceeds to step S13.

On the other hand, in step S10, a laser crystal large substrate having a predetermined thickness h is produced.
In step S11, 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 S12, the two surfaces of the laser crystal substrate 11 on which the laser beam is incident or emitted are optically polished to form a necessary AR film or HR film. For example, an AR film for the fundamental wave is formed on one of the two surfaces, and an HR film is formed on the other.
Then, the process proceeds to step S13.

In step S13, as shown in FIG. 14, the surface 12i of the first composite substrate 21 on which the AR film is formed 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. A second composite substrate 22 ″ as shown in FIG.
As the bonding method, an adhesive may be used, or an optical contact may be used.

  In step S17, the second composite substrate 22 ″ is cut along the cutting line C as shown in FIG.

  According to the second embodiment, a plurality of optical elements 10 whose end surfaces are convex can be manufactured together. In addition, since the wavelength conversion crystal 2 and the dummy material 3 are bonded together and then a manufacturing method of bonding to the laser crystal 1 can be adopted, the bonding area to the laser crystal 1 is the wavelength conversion crystal 2 and the dummy material 3. And the combined area. For this reason, the bonding operation is facilitated, and the manufacturing work efficiency 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. Further, if a material having better thermal conductivity than the laser crystal 1 and the wavelength conversion crystal 2 is used as the dummy material 3, temperature control becomes easier than when the dummy material 3 is not provided.

FIG. 16 is a flowchart illustrating the manufacturing procedure of the optical element 10 according to the third embodiment.
Steps S1 to S6 are the same as those in the first embodiment. After step S6, the process proceeds to step S13.
Steps S10 to S12 are the same as those in the second embodiment. After step S12, the process proceeds to step S13.

In step S13, as shown in FIG. 17, the surface 12i of the first composite substrate 21 on which the AR film is formed 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. A second composite substrate 22 as shown in FIG.
As the bonding method, an adhesive may be used, or an optical contact may be used.

In step S14, as shown in FIG. 19, incisions K are made in a square or substantially square lattice shape on the surface of the second composite substrate 22 on the first composite substrate 21 side to form a second composite substrate 22 ′.
In step S15, the surface of the second composite substrate 22 ′ is polished by using an abrasive and an elastic polishing pad so as to cause surface sag from the edge portion of the cut K. Thereby, as shown in FIG. 15, each surface surrounded by the cut K becomes a convex surface. This is referred to as a second composite substrate 22 ″.

  In step S16, the required AR film or HR film is formed on the two surfaces of the second composite substrate 22 "facing the polarization reversal direction Dr. For example, the AR film for the fundamental wave is formed on one of the two surfaces. The HR film is formed on the other side.

  In step S17, the second composite substrate 22 ″ is cut along the cutting line C as shown in FIG.

  According to the third embodiment, it is possible to manufacture a plurality of optical elements 10 whose end faces are convex. In addition, since the wavelength conversion crystal 2 and the dummy material 3 are bonded together and then a manufacturing method of bonding to the laser crystal 1 can be adopted, the bonding area to the laser crystal 1 is the wavelength conversion crystal 2 and the dummy material 3. And the combined area. For this reason, the bonding operation is facilitated, and the manufacturing work efficiency 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. Further, if a material having better thermal conductivity than the laser crystal 1 and the wavelength conversion crystal 2 is used as the dummy material 3, temperature control becomes easier than when the dummy material 3 is not provided.

As shown in FIGS. 20 and 21, a spacer 5 may be sandwiched between the laser emission surface 1 o of the laser crystal 1, the laser light incident surface 2 i of the wavelength conversion crystal 2, and the surface 3 d of the dummy material 3.
The spacer 5 is preferably made of a material that transmits fundamental laser light and has a thermal expansion coefficient comparable to that of the laser crystal 1.

  According to the optical element 10 according to Example 4, the etalon effect by the adhesive can be controlled by making the thickness of the spacer 5 appropriate.

  In the groove forming step S6 in FIGS. 3 and 13 and the groove forming step S14 in FIG. 16, the cuts K may be made in a plurality of circular shapes as shown in FIG. In this case, in the cutting step S9 in FIG. 3 and the cutting step S17 in FIG. 13 and FIG. 16, the cutting line C may be cut off as shown in FIG.

(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 substrate, 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.

As shown in FIG. 24, the optical element 10 of the present invention is placed on the base B, positioned against the stopper S, and fixed to the base B. At this time, since the flat portion Pk at the bottom of the cut K remains around the convex surface, the flat portion Pk hits the plane of the stopper S, so that positioning can be suitably performed.
If there is no flat portion Pk around the convex surface, the convex surface hits the stopper S. In that case, if the contact surface of the stopper S is a flat surface, it becomes point contact and positioning becomes difficult. On the other hand, if the stopper S is processed into a concave surface, surface contact can be made, but such processing is difficult.

  An optical element having a convex surface may be produced by performing groove processing on a laser crystal, optical glass, or the like to make a cut, and then polishing to cause surface sagging.

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

1 is a perspective view showing an optical element according to Example 1. FIG. 1 is an exploded perspective view showing an optical element according to Example 1. FIG. 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 wavelength conversion crystal substrate. It is a perspective view which shows a dummy material board | substrate. It is a perspective view which shows a 1st composite substrate. It is a perspective view which shows the 1st composite substrate which cut | notched. It is a perspective view which shows the 1st composite substrate grind | polished so that a surface sagging may occur. It is a perspective view which shows the cutting | disconnection of a 1st composite substrate. 6 is a perspective view showing an optical element according to Example 2. FIG. 6 is an exploded perspective view showing an optical element according to Embodiment 2. FIG. FIG. 6 is a flowchart showing a manufacturing procedure of an optical element according to Example 2. 6 is a perspective view showing a bonding process of a first composite substrate and a laser crystal substrate according to Example 2. FIG. It is a perspective view which shows a 2nd composite substrate. 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 bonding process of the 1st composite substrate based on Example 3, and a laser crystal substrate. 10 is a perspective view showing a second composite substrate according to Example 3. FIG. It is a perspective view which shows the 2nd composite board | substrate which cut | notched. 10 is a perspective view showing an optical element according to Example 4. FIG. 10 is an exploded perspective view showing an optical element according to Example 4. FIG. 10 is a top view showing a plurality of circular cuts according to Embodiment 5. FIG. FIG. 10 is a top view illustrating a cutting line according to a fifth embodiment. 10 is a side view showing a method for fixing an optical element according to Embodiment 7. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser crystal 1o Laser beam emission surface 2 Wavelength conversion crystal 2i Laser beam incident surface 3 Dummy material 5 Spacer 9,10 Optical element 21 First composite substrate 22 Second composite substrate K Notch

Claims (6)

Polishing the entire surface of the plate-like body using a groove-forming step of forming grooves in a square or substantially square lattice shape or a plurality of circular shapes on the surface of the plate-like body containing the optical material, and a resilient polishing pad it, the optical element characterized by having a polishing step of polishing the entire surface than to undergo dullness edge portion of the groove, and a separation step of obtaining a plurality of optical elements by cutting separated by the groove Manufacturing method. 2. The method of manufacturing an optical element according to claim 1, wherein the optical material is glass, a laser crystal, or a wavelength conversion crystal . One surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12), one surface of which is a laser light incident surface (12i), or the one surface (12a) and the one surface (12a). A first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to one surface (12a) to form a first composite substrate (21), and the laser light incident surface of the first composite substrate (21) The entire surface opposite to the laser light incident surface (12i) by using a cutting step for making incisions (K) into a lattice shape or a plurality of circular shapes on the surface opposite to (12i) and a resilient polishing pad A plurality of optical elements (9) are obtained by polishing the entire surface so as to cause surface sag at the edge of the cut (K), and cutting and separating the cut (K). Separation step The method for manufacturing an optical element characterized by having a. One surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12), one surface of which is a laser light incident surface (12i), or the one surface (12a) and the one surface (12a). A first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to one surface (12a) to form a first composite substrate (21), and the laser light incident surface of the first composite substrate (21) The entire surface opposite to the laser light incident surface (12i) by using a cutting step for making incisions (K) into a lattice shape or a plurality of circular shapes on the surface opposite to (12i) and a resilient polishing pad There is a polishing step for polishing the entire surface so as to cause surface sag at the edge portion of the notch (K), and the laser light incident surface (12i) of the first composite substrate (21). Surface and plate shape The second composite substrate (22) is formed by attaching the laser crystal emission surface (11o) of the laser crystal emission surface (11o) to the surface having the laser light emission surface (11o). A method of manufacturing an optical element , comprising: a substrate manufacturing step; and a separation step of obtaining a plurality of optical elements (10) by cutting and separating with the cut (K) . One surface (12a) other than the laser light incident surface (12i) of the wavelength conversion crystal substrate (12), one surface of which is a laser light incident surface (12i), or the one surface (12a) and the one surface (12a). A first composite substrate manufacturing step of attaching a plate-like dummy material substrate (13) to one surface (12a) to form a first composite substrate (21), and the laser light incident surface of the first composite substrate (21) A surface having (12i) and a surface of the laser crystal substrate (11), which is a plate-like body and one surface of which is the laser light emitting surface (11o), are attached to the second surface. A second composite substrate manufacturing step as a composite substrate (22), and a surface of the second composite substrate (22) opposite to the laser crystal substrate (11) attachment surface are cut into a lattice shape or a plurality of circular shapes. Cutting step to insert (K) and The entire surface of the laser crystal substrate (11) opposite to the application surface is polished by using an elastic polishing pad, so that the entire surface is polished so as to cause surface sag at the edge of the cut (K). And a separation step of obtaining a plurality of optical elements by cutting and separating at the cut (K) . The optical element manufacturing method according to claim 4 or 5, wherein a spacer (5) is sandwiched between the first composite substrate (3) and the laser crystal substrate (11), and the same as the spacer (5). The first composite substrate (3), the spacer (5), the spacer (5), and the laser crystal substrate (11) are bonded to each other with an adhesive having substantially the same refractive index. Method.

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