JP7391710B2 - Fiber structures, optical combiners, laser light sources and laser devices - Google Patents

Description

The present invention relates to a fiber structure, an optical combiner, and a laser device.

In a laser light source such as a high-power fiber laser, an optical combiner is generally used that combines excitation light from a plurality of light sources and makes the combined light enter an optical resonator.

The optical combiner includes a first optical fiber section having a plurality of optical fiber strands, a second optical fiber section having one optical fiber strand, and a support member that accommodates and supports these. . The support member has a base portion and a side wall portion extending from the edge of the main surface of the base portion. In the support member, the end surfaces of the plurality of optical fiber strands of the first optical fiber section and the end surfaces of the optical fiber strands of the second optical fiber section are fusion-spliced.

As such an optical combiner, for example, one disclosed in Patent Document 1 listed below is known. In the same document, in order to fix the first optical fiber part and the second optical fiber part to the support member, the first optical fiber part and the second optical fiber part are fixed with a fixing resin on the main surface and side walls of the base part of the support member. It is disclosed that the device is fixed by adhering to the portion.

JP 2017-191298 Publication

However, the optical combiner described in Patent Document 1 has room for improvement in terms of the quality of the beam output from the combiner.

Note that the quality of the beam can be measured using, for example, M ² (M square). M ² is a parameter indicating how small the beam can be focused, and it is said that the smaller M ² is, the better the quality of the beam is.

The present invention has been made in view of the above circumstances, and provides a fiber structure and an optical combiner that can suppress deterioration in the quality of the beam output from the optical combiner even when placed in an environment with large temperature changes. , an object of the present invention is to provide a laser light source and a laser device.

The present inventors have made repeated studies to solve the above problems. First, the inventors considered that the following may occur when an optical combiner is placed in an environment with large temperature changes. That is, when the optical combiner is placed in a high temperature environment, the fixed resin expands and presses the main surface of the base portion. At this time, due to the reaction from the base part to the fixed resin, the fixed resin is subjected to stress in the direction of separating from the base part. Accordingly, the position of the fixed portion of the first optical fiber portion that is fixed with the fixing resin is shifted in the direction away from the base portion. As a result, the fixed part of the first optical fiber part has a position regulating part where the position of the fixed part of the first optical fiber part is regulated by the second optical fiber part between the fixing resin and the end surface of the first optical fiber part. It will be bent against. On the other hand, when the optical combiner is placed in a low-temperature environment, the fixed resin contracts and the main surface of the base portion is pulled toward the fixed resin. At this time, due to the reaction from the fixed resin to the base part, the fixed resin is subjected to stress in the direction of the main surface of the base part. Accordingly, the position of the fixed portion of the first optical fiber portion is shifted in a direction closer to the base portion. As a result, the fixed portion of the first optical fiber portion is bent relative to the position regulating portion of the first optical fiber portion. In this manner, when the optical combiner is placed in an environment with large temperature changes, the fixed portion of the first optical fiber portion is bent relative to the position regulating portion of the first optical fiber portion. Similarly, when the optical combiner is placed in an environment with large temperature changes, the fixed portion of the second optical fiber portion will be bent relative to the position regulating portion of the second optical fiber portion. Therefore, in order to improve the quality of the beam output from the optical combiner, even if the optical combiner is placed in an environment with large temperature changes, the first light The fixed part of the fiber part is prevented from being bent relative to the position regulating part of the first optical fiber part, and the fixed part of the second optical fiber part is prevented from being bent relative to the position regulating part of the second optical fiber part. I thought it would be important to prevent this from happening. Therefore, as a result of further intensive studies, the present inventors discovered that the above-mentioned problem could be solved by the following invention.

That is, the present invention provides a fiber structure comprising an optical fiber section having a bare optical fiber, a support member that supports the optical fiber section, and a fixing section that fixes the optical fiber section to the support member. , the support member has a base portion facing the optical fiber portion, and a side wall portion extending from a main surface of the base portion and facing the optical fiber portion, and the fixing portion is larger than the fixing portion. The fiber structure is fixed to the main surface of the base part via a buffer part having a low Young's modulus, and is also fixed to the side wall part.

According to the fiber structure (first fiber structure) of the present invention, a second fiber structure having a similar configuration is prepared, and the end face of the optical fiber strand of the optical fiber portion of the second fiber structure, When an optical combiner is formed by fusion splicing the end faces of the optical fibers of the first fiber structure so that the support member of the first fiber structure also serves as the support member of the second fiber structure, the optical combiner , the position of the optical fiber portion of the first fiber structure is regulated by the second fiber structure.

At this time, when the first fiber structure is placed in a high temperature environment, the fixing part expands and presses the main surface of the base part via the buffer part. At this time, the buffer part has a lower Young's modulus than the fixed part and is softer than the fixed part. Therefore, even if the fixed part expands, the pressing force from the fixed part to the base part is alleviated by the buffer part. As a result, the reaction force from the base portion to the fixed portion is reduced, and the stress that the fixed portion receives in the direction of moving away from the base portion is reduced. Accordingly, the position of the fixed portion of the first optical fiber portion that is fixed by the fixing portion becomes difficult to shift in the direction away from the base portion. As a result, the first optical fiber portion is covered with respect to the position regulating portion whose position is regulated by the second optical fiber portion between the fixed portion of the first optical fiber portion and the end face of the first optical fiber portion. The fixed part becomes difficult to bend.

On the other hand, when the fiber structure is placed in a low-temperature environment, the fixing part contracts, and the main surface of the base part is pulled toward the fixing part via the buffer part. At this time, the buffer part has a lower Young's modulus than the fixed part and is softer than the fixed part. Therefore, even if the fixed part contracts, the buffer part expands, so that the reaction from the fixed part to the base part is reduced, and the stress that the fixed part receives in the direction of the main surface of the base part is reduced. Accordingly, the position of the fixed portion of the first optical fiber portion becomes difficult to shift in the direction toward the base portion. As a result, the fixed portion of the first optical fiber portion is less likely to be bent with respect to the position regulating portion of the first optical fiber portion.

As described above, according to the fiber structure of the present invention, even when placed in an environment with large temperature changes, the fixed part of the optical fiber part is difficult to bend with respect to the position regulating part of the optical fiber part. . Therefore, when an optical combiner is formed using the fiber structure of the present invention, even if the optical combiner is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the optical combiner can be suppressed. be able to.

In the above fiber structure, it is preferable that the ratio of the Young's modulus of the buffer section to the Young's modulus of the fixing section is 0.3 or less.

In this case, even if the fiber structure is placed in an environment with large temperature changes, the fixed part of the optical fiber part is However, the optical fiber section is less likely to be bent by the position regulating section, and deterioration in the quality of the beam output from the optical combiner can be further suppressed.

In the above-mentioned fiber structure, it is preferable that the base part is provided between the main surface and the buffer part, and has a protrusion part that projects from the main surface toward the optical fiber part.

In this case, when the fiber structure is placed in a high-temperature environment and the buffer section is pressed and compressed by the expansion of the fixing section, the buffer The portion easily spreads outward from the protruding portion, and the stress from the fixing portion to the buffer portion becomes easier to relax. As a result, the fixed part of the optical fiber part becomes even more difficult to bend with respect to the position regulating part of the optical fiber part, and it is possible to further suppress deterioration in the quality of the beam output from the optical combiner.

The present invention also provides an optical combiner comprising a first fiber structure and a second fiber structure, wherein the first fiber structure and the second fiber structure are composed of the above-mentioned fiber structures, and In the first fiber structure, the optical fiber section has a plurality of the optical fiber strands, and in the second fiber structure, the optical fiber section has one optical fiber strand. , an end face of the optical fiber part of the first fiber structure and an end face of the optical fiber part of the second fiber structure are fusion-spliced, and the support member of the first fiber structure is connected to the end face of the optical fiber part of the second fiber structure. This is an optical combiner that also serves as the support member for the two-fiber structure.

According to this optical combiner, even if the first fiber structure is placed in an environment with large temperature changes, the fixed part of the first optical fiber part does not bend with respect to the position regulating part of the first optical fiber part. It becomes difficult to get caught. On the other hand, even if the second fiber structure is placed in an environment with large temperature changes, the fixed portion of the second optical fiber portion is less likely to be bent with respect to the position regulating portion of the second optical fiber portion. Therefore, according to the optical combiner of the present invention, even if the optical combiner is placed in an environment with large temperature changes, it is possible to suppress deterioration in the quality of the beam output from the optical combiner.

The present invention also provides the above-mentioned optical combiner and an optical resonator that emits light of a specific wavelength as a laser beam based on the light emitted from the optical fiber strand of the second fiber structure of the optical combiner. and an excitation light source that makes excitation light incident on each of the plurality of optical fiber strands of the first fiber structure of the optical combiner.

According to this laser light source, excitation light is incident on each of the plurality of optical fiber strands of the first fiber structure of the optical combiner from the excitation light source, and from the optical fiber strand of the second fiber structure of the optical combiner. Based on the emitted light, light of a specific wavelength is emitted from the optical resonator as a laser beam. At this time, even if the optical combiner is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the optical combiner can be suppressed. Therefore, even if the laser light source of the present invention is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the laser light source can be suppressed.

Furthermore, the present invention provides a laser device comprising a plurality of laser light sources and an optical combiner that combines and emits laser light incident from the plurality of laser light sources, the optical combiner being composed of the above-described optical combiner. be.

According to this laser device, laser beams are input from the plurality of laser light sources into the first fiber structure of the optical combiner, are combined, and are emitted as laser beams from the second fiber structure. At this time, the optical combiner is composed of the optical combiner described above, and even if the optical combiner is placed in an environment with large temperature changes, it is possible to suppress deterioration in the quality of the beam output from the optical combiner. Therefore, even if the laser device of the present invention is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the laser device can be suppressed.

In the above laser device, it is preferable that the laser light source is the above-mentioned laser light source.

In this case, the laser light source is composed of the above-mentioned laser light source, and even if the laser light source is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the laser light source can be suppressed. Therefore, even if the laser device of the present invention is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the laser device can be further suppressed.

According to the present invention, there are provided a fiber structure, an optical combiner, a laser light source, and a laser device that can suppress deterioration in the quality of a beam output from an optical combiner even when placed in an environment with large temperature changes. Ru.

1 is a plan view showing an embodiment of an optical combiner of the present invention. FIG. 2 is a partially cutaway end view taken along line II-II in FIG. 1; 2 is a sectional view taken along line III-III in FIG. 1. FIG. 2 is a sectional view taken along line IV-IV in FIG. 1. FIG. FIG. 4 is an enlarged view of the optical fiber shown in FIG. 3; FIG. 2 is a partial side view showing an optical combiner as an analytical model used to demonstrate the effects of the optical combiner of the present invention. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. FIG. 3 is a graph showing the relationship between the amount of displacement in the Y direction of the coated optical fiber in the optical combiner (3-1 to 3-4) and the Z coordinate. 3 is a graph showing the relationship between the reciprocal (1/r) of the radius of curvature r of the coated optical fibers in the optical combiners (3-1 to 3-4) and the Z coordinate. 2 is a graph showing curvature integral values (sum of peak areas) in optical combiners (1-1 to 1-4, 2-1 to 2-4, and 3-1 to 3-4). FIG. 1 is a schematic diagram showing an embodiment of a laser light source of the present invention. 1 is a schematic diagram showing an embodiment of a laser device of the present invention. FIG. 7 is a partially cutaway end view showing another embodiment of the optical combiner of the present invention. FIG. 7 is a partially cutaway end view showing still another embodiment of the optical combiner of the present invention.

<Optical combiner>
Hereinafter, embodiments of the optical combiner of the present invention will be described in detail with reference to FIGS. 1 to 5. 1 is a plan view showing an embodiment of the optical combiner of the present invention, FIG. 2 is a partially cutaway end view taken along the line II-II in FIG. 1, and FIG. 3 is a plan view taken along the line III-III in FIG. 4 is a sectional view taken along line IV--IV in FIG. 1, and FIG. 5 is an enlarged view showing the optical fiber strand of FIG. 3.

As shown in FIGS. 1 and 2, the optical combiner 100 includes a first fiber structure 101 having a first optical fiber section 101a having a plurality of optical fibers 21, and a first fiber structure 101 having a first optical fiber section 101a having a plurality of optical fibers 21. and a second fiber structure 102 having a second optical fiber portion 102a.

The first fiber structure 101 and the second fiber structure 102 each include a support member 10 having an accommodation groove 10a that accommodates and supports the first optical fiber section 101a and the second optical fiber section 102a. The support member 10 has a base portion 11 and two side wall portions 12 extending from both edges of the main surface 11a of the base portion 11 and facing each other (see FIGS. 3 and 4). Here, the support member 10 in the first fiber structure 101 also serves as the support member 10 in the second fiber structure 101.

The first fiber structure 101 includes a first fixing section 30 that fixes the first optical fiber section 101a to the support member 10, and a buffer section 50 provided between the first fixing section 30 and the main surface 11a of the base section 11. It also has the following. The first fixing part 30 is fixed to each of the two side wall parts 12 by adhesive, and is also fixed to the main surface 11a of the base part 11 via the buffer part 50 by adhesive. Here, the first fixing section 30 is provided so as to surround the first optical fiber section 101a. In this way, the first fixing part 30 is fixed to the support member 10. The buffer portion 50 has a lower Young's modulus than the first fixed portion 30.

The first optical fiber section 101a has a coating section 101A and a wire exposed section 101B adjacent to the coating section 101A. The coating section 101A includes a plurality of optical fiber strands 21 and a coating 22 that covers each of the plurality of optical fiber strands 21 (see FIG. 3), and the strand exposed section 101B has an exposed It consists of a plurality of optical fiber strands 21. Here, the plurality of optical fiber strands 21 are optical fiber strands common to the covering portion 101A and the strand exposed portion 101B. That is, the extended portion of the optical fiber strand 21 of the covering portion 101A is configured as the optical fiber strand 21 of the strand exposed portion 101B. Note that hereinafter, the optical fiber 21 in the coating portion 101A and the bare wire exposed portion 101B and the coating 22 in the coating portion 101A will be collectively referred to as the optical fiber 20.

On the other hand, the second fiber structure 102 includes a second fixing section 30 that fixes the second optical fiber section 102a to the support member 10, and a buffer provided between the second fixing section 30 and the main surface 11a of the base section 11. It further includes a section 50. The second fixing portion 30 is fixed to each of the two side wall portions 12 by adhesive, and is also fixed to the main surface 11a of the base portion 11 via the buffer portion 50 by bonding. Here, the second fixing section 30 is provided so as to surround the second optical fiber section 102a. In this way, the second fixing part 30 is fixed to the support member 10. The buffer portion 50 has a lower Young's modulus than the second fixed portion 30.

The second optical fiber section 102a has a coating section 102A and a wire exposed section 102B adjacent to the coating section 102A. The coating section 102A includes one optical fiber strand 21 and a coating 22 that covers the optical fiber strand 21 (see FIG. 4), and the strand exposed section 102B covers the exposed optical fiber strand 21. It consists of line 21. Here, one optical fiber strand 21 is an optical fiber strand common to the covering portion 102A and the strand exposed portion 102B. That is, the extension of the optical fiber strand 21 of the covering portion 102A is configured as the optical fiber strand 21 of the strand exposed portion 102B. Note that hereinafter, the optical fiber 21 in the coating portion 102A and the bare wire exposed portion 102B and the coating 22 in the coating portion 102A will also be collectively referred to as the optical fiber 20.

Then, the end face of the bare wire exposed portion 101B of the first optical fiber portion 101a of the first fiber structure 101 and the end face of the bare wire exposed portion 102B of the second optical fiber portion 102a of the second fiber structure 102 are fused together. It is connected. Here, as shown in FIG. 5, the optical fiber wire 21 has a core 21a and a cladding 21b surrounding the core 21a, and the light incident on the optical combiner 100 is transmitted through the first fiber structure. It passes through the core 21a of the optical fiber strand 21 of No. 101 and then through the core 21a of the optical fiber strand 21 of the second fiber structure 102. In this way, the first fiber structure 101 and the second fiber structure 102 are accommodated in the accommodation groove 10a of the support member 10 in an optically coupled state.

Further, the first fiber structure 101 includes a sealing portion 40 that covers the boundary between the covering portion 101A and the exposed wire portion 101B.

On the other hand, the second fiber structure 102 also includes a sealing part 40 that covers the boundary between the covering part 102A and the bare wire exposed part 102B.

The sealing portion 40 is bonded to the main surface 11a of the base portion 11 of the support member 10 and to each of the two side wall portions 12.

Further, in the first fiber structure 101 and the second fiber structure 102, the sealing part 40 is adhered to the first fixing part 30 and the second fixing part 30, respectively. Here, the first fixing part 30 and the second fixing part 30 have greater adhesive strength to the support member 10 than the sealing part 40.

According to the optical combiner 100, the end face of the strand exposed portion 101B of the first optical fiber portion 101a of the first fiber structure 101 and the strand exposed portion 102B of the second optical fiber portion 102a of the second fiber structure 102 are fusion-spliced to the end faces of. Therefore, the optical fiber section 101a of the first fiber structure 101 is regulated by the second fiber structure 102.

At this time, when the first fiber structure 101 is placed in a high temperature environment, the first fixing part 30 expands and presses the main surface 11a of the base part 11 via the buffer part 50. At this time, the buffer part 50 has a lower Young's modulus than the first fixed part 30 and is softer than the first fixed part 30. Therefore, even if the first fixing section 30 expands, the pressing force from the first fixing section 30 to the base section 11 is alleviated by the buffer section 50. As a result, the reaction force from the base part 11 to the first fixing part 30 becomes smaller, and the stress that the first fixing part 30 receives in the direction of separating from the base part 11 becomes smaller. Accordingly, the position of the fixed portion of the first optical fiber portion 101a that is fixed by the first fixing portion 30 becomes difficult to shift in the direction away from the base portion 11. As a result, the position regulating part of the first optical fiber part 101a whose position is regulated by the second optical fiber part 102a between the first fixing part 30 and the end face of the second optical fiber part 102a is 1. The fixed portion of the optical fiber portion 101a becomes difficult to bend.

On the other hand, when the first fiber structure 101 is placed in a low-temperature environment, the first fixing part 30 contracts, and the main surface 11a of the base part 11 is pulled toward the first fixing part 30 via the buffer part 50. . At this time, the buffer part 50 has a lower Young's modulus than the first fixed part 30 and is softer than the first fixed part 30. Therefore, even if the first fixing part 30 contracts, the buffer part 50 expands, so the reaction from the first fixing part 30 to the base part 11 becomes small, and the first fixing part 30 The stress received in the direction becomes smaller. Accordingly, the position of the fixed portion of the first optical fiber portion 101a becomes difficult to shift in the direction toward the base portion 11. As a result, the fixed portion of the first optical fiber portion 101a becomes difficult to bend with respect to the position regulating portion of the first optical fiber portion 101a.

As described above, according to the first fiber structure 101, even when placed in an environment with large temperature changes, the fixed part of the first optical fiber part 101a can be kept relative to the position regulating part of the first optical fiber part 101a. This makes it difficult to bend.

Similarly, according to the second fiber structure 102, even if it is placed in an environment with large temperature changes, the fixed part of the second optical fiber part 102a that is fixed by the second fixing part 30 is It becomes difficult to bend with respect to the position regulating part whose position is regulated by the optical fiber part 101a of the first fiber structure 101 between the fixed part 30 and the end surface of the first optical fiber part 101a.

From the above, according to the optical combiner 100, deterioration in the quality of the beam output from the optical combiner 100 can be suppressed.

Further, in the first fiber structure 101 and the second fiber structure 102, the sealing part 40 is adhered to the first fixing part 30 and the second fixing part 30, respectively, and 30 has greater adhesion strength to the support member 10 than the sealing part 40.

In this way, the first fiber structure 101 and the second fiber structure 102 are attached to the support member 10 at the first fixing part 30 and the second fixing part 30, which have a greater adhesive strength to the support member 10 than the sealing part 40. By being fixed to , the fixation of the first fiber structure 101 and the second fiber structure 102 to the support member 10 is reinforced. Therefore, separation of the first fiber structure 101 and the second fiber structure 102 from the support member 10 can be suppressed.

Next, the support member 10, optical fiber 20, first fixing section 30, second fixing section 30, sealing section 40, and buffer section 50 in the optical combiner 100 will be explained in detail.

(Support member)
The material constituting the support member 10 is not particularly limited, and may be either a resin or an inorganic material, but is preferably composed of an inorganic material. In this case, since the inorganic material is harder than resin, it can protect the first optical fiber section 101a and the second optical fiber section 102a from external force, impact, and vibration. Furthermore, since the inorganic material has a smaller coefficient of thermal expansion than resin, thermal expansion or thermal contraction due to changes in the surrounding temperature environment is suppressed, and the occurrence of microbends in the optical fiber 20 is suppressed. It is possible to suppress the deterioration of the optical properties in . Examples of such inorganic materials include glass materials such as Neoceram (registered trademark) and quartz.

(optical fiber)
The optical fiber 20 has an optical fiber strand 21 and a coating 22. Here, the coating 22 is preferably made of a material having a refractive index smaller than the refractive index of the cladding 21b of the optical fiber strand 21. Examples of the material constituting the coating 22 include silicone resin and polyamide resin.

(First fixed part and second fixed part)
The first fixing part 30 and the second fixing part 30 may be made of a material that can fix the first fiber structure 101 and the second fiber structure 102 to the support member 10. Examples of materials constituting the first fixing part 30 and the second fixing part 30 include silicone resin and epoxy resin.

The Young's modulus of each of the first fixing part 30 and the second fixing part 30 is not particularly limited, but is usually 0.1 MPa or more, preferably 1 MPa or more. However, the Young's modulus of the first fixing portion 30 or the second fixing portion 30 is preferably 100 MPa or less. Note that in this specification, Young's modulus refers to a value at room temperature (23° C.).

（上記式（１）中、Ｒは、二価の有機フッ素化合物基を表し、ｎは１以上の整数を表す。） (Sealing part)
The sealing portion 40 may be made of a material having sealing performance, and such a material includes, for example, a fluororesin having a structure represented by the following formula (1).

(In the above formula (1), R represents a divalent organic fluorine compound group, and n represents an integer of 1 or more.)

（上記式（２）中、Ｒは、二価の有機フッ素化合物基を表し、ｎは１以上の整数を表す。Ｒ^１～Ｒ^４は各々独立に、有機基を表す。） This fluororesin can be obtained by crosslinking a crosslinkable compound containing a structure represented by the following formula (2) in its main chain using ultraviolet rays or heating.

(In the above formula (2), R represents a divalent organic fluorine compound group, and n represents an integer of 1 or more. R ¹ to R ⁴ each independently represent an organic group.)

R in the above formulas (1) and (2) may be a divalent organic fluorine compound group, and examples of the divalent organic fluorine compound group include -CF ₂ -CF(CF ₃ )-O-, -CF ₂ -O-, -CF ₂ -CF ₂ -O-, and -CF ₂ -CF ₂ -CF ₂ -O- are preferred.

In this case, the sealing part 40 has a C-F bond and a Si-O bond that have larger bond energy than a C-C bond and a C-H bond, so the heat resistance of the sealing part 40 is improved. The durability of the first fiber structure 101 and the second fiber structure 102 can be further improved.

The organic groups represented by R ¹ to R ⁴ in the above formula (2) include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, etc., which have a CH ₂ =CH- structure at the end. and hydrocarbon groups such as alkyl groups.

Although the refractive index of the sealing part 40 is not particularly limited, it is preferably smaller than the refractive index of the cladding 21b. In this case, it becomes possible to confine light within the optical fiber wire 21.

Although the Young's modulus of the sealing portion 40 is not particularly limited, it is preferably 10 MPa or less.

In this case, when light enters the first fiber structure 101 of the optical combiner 100 and exits from the second fiber structure 102 of the optical combiner 100, the Young's modulus of the sealing part 40 exceeds 10 MPa. , the beam quality of the emitted light can be further improved.

However, in order to maintain the shape of the sealing part 40, it is preferable that the Young's modulus of the sealing part 40 is 1 kPa or more.

(buffer)
The buffer portion 50 may have a lower Young's modulus than the first fixed portion 30 and the second fixed portion 30. That is, the ratio R of the Young's modulus of the buffer section 50 to the Young's modulus of the first fixing section 30 or the second fixing section 30 only needs to be smaller than 1.

However, R is preferably 0.3 or less. In this case, even if the optical combiner 100 is placed in an environment with large temperature changes, the fixed portion of the first optical fiber section 101a will be more stable than when R exceeds 0.3. It becomes more difficult to bend with respect to the position regulating part. Further, the fixed portion of the second optical fiber portion 102a is also less likely to be bent with respect to the position regulating portion of the second optical fiber portion 102a. Therefore, deterioration in the quality of the beam output from the optical combiner 100 can be further suppressed.

However, consideration should be given to ensuring that the buffer part 50 has a Young's modulus that allows it to maintain its shape, and to prevent excessive stress from being applied to the optical fiber strand 21 by the first fixing part 30 and the second fixing part 30 having a high Young's modulus. Therefore, R is preferably 1×10 ⁻⁵ or more.

Further, the buffer section 50 may have a Young's modulus greater than or equal to the Young's modulus of the base portion 11, or may have a Young's modulus lower than the Young's modulus of the base portion 11. It functions particularly effectively when it has a Young's modulus lower than that of the portion 11. The ratio R1 of the Young's modulus of the buffer portion 50 to the Young's modulus of the base portion 11 may be smaller than 1.

Here, in order to confirm the effects of the present invention, an optical combiner having the following configuration was used as an analytical model, and the combination of Young's modulus of the fixed part and the buffer part was set as shown in Table 1 under the following analytical conditions. Twelve different optical combiners (1-1 to 1-4, 2-1 to 2-4, and 3-1 to 3-4) were analyzed. At this time, in the analysis, finite element method analysis software (product name "ANSYS", manufactured by ANSYS Incorporated) was used. The results are shown in Figures 9-11.

FIG. 9 shows the relationship between the amount of displacement in the Y direction and the Z coordinate in the optical fiber 20 for the optical combiner (3-1 to 3-4) shown in FIG. 6, that is, the distribution of the amount of displacement in the Y direction in the optical fiber 20. FIG. 10 is a graph showing the relationship between the reciprocal (1/r) of the radius of curvature r and the Z coordinate in the optical fiber 20 for the optical combiners (3-1 to 3-4) shown in FIG. 3 is a graph showing the distribution of the reciprocal (1/r) of the radius of curvature r in FIG.

FIG. 11 is a graph showing the curvature integral values of the optical combiners (1-1 to 1-4, 2-1 to 2-4, and 3-1 to 3-4) shown in FIG. Here, the integral value of curvature is the integral value (total sum) of the area of the peak of the reciprocal of the radius of curvature r (1/r) in the region of the first optical fiber section (z coordinate = 0 to 40 mm) in FIG. show.

Note that FIG. 9 also shows the displacement distribution in the Y direction in the optical fiber 20 without the buffer section 50, and FIG. 10 shows the reciprocal of the radius of curvature r of the optical fiber 20 without the buffer section 50. (1/r) distribution is shown. Furthermore, in FIGS. 9 and 10, the broken line at the z-coordinate of 40 mm indicates the fusion location between the first optical fiber section 101a and the second optical fiber section 102a. Further, FIG. 11 also shows the curvature integral value when the buffer section 50 is not provided.

<Configuration of optical combiner>
The configuration of the optical combiner was as follows.
(First optical fiber section)
Number of optical fibers: 7 Outer diameter: 175μm
Material of optical fiber: quartz Physical properties of optical fiber: Young's modulus E = 72000 MPa, Poisson's ratio ν = 0.17
Outer diameter of coating: 390μm
Physical properties of coating: Young's modulus E = 700 MPa, Poisson's ratio ν = 0.35
Length of exposed wire in Z direction: 20mm (see Figure 6)
Length of the covering part excluding the first fixing part: 5mm (see Figure 6)
(Second optical fiber section)
Number of optical fibers: 1 Outer diameter: 550μm
Material of optical fiber: quartz Physical properties of optical fiber: Young's modulus E = 72000 MPa, Poisson's ratio ν = 0.17
Outer diameter of coating: 800μm
Physical properties of coating: Young's modulus E = 700 MPa, Poisson's ratio ν = 0.35
Length of exposed wire in Z direction: 20mm (see Figure 6)
Length of the covered part excluding the second fixing part: 5mm (see Figure 6)
(First fixed part)
Length of first fixing part in Z direction: 15mm (see Figure 6)
Cross-sectional dimensions of the first fixed part: 1.5 mm x 1.5 mm (see Figure 7)
(Second fixed part)
Length of second fixing part in Z direction: 15mm (see Figure 6)
Cross-sectional dimensions of the second fixing part: 1.5mm x 1.5mm (see Figure 8)
(buffer)
Width in X direction: 1.5mm
Thickness in Y direction: 0.5mm
Length in Z direction: 15mm
<Analysis conditions>
The analysis was conducted under temperature conditions such that the coefficient of thermal expansion (=coefficient of thermal expansion α×ΔT) of the first fixing part 30 and the second fixing part 30 was −1%.

From the results shown in FIG. 9, in the optical combiner having the buffer part 50, when the Z coordinate is 0 to 16 mm or 64 to 80 mm, that is, in the area where the optical fiber 20 is fixed by the fixing part 30, the buffer part 50 It can be seen that the amount of displacement in the Y direction is significantly smaller than that of the optical combiner without the optical combiner. Although FIG. 9 shows the results for optical combiners 3-1 to 3-4, similar results were obtained for optical combiners 1-1 to 1-4 and 2-1 to 2-4. It is being

Furthermore, from the results shown in FIG. 10, in the optical combiner having the buffer part 50, when the Z coordinate is 0 to 16 mm or 64 to 80 mm, that is, in the area where the optical fiber 20 is fixed by the fixing part 30, the buffer part It can be seen that the peak of the reciprocal of the radius of curvature r is significantly smaller than that of the optical combiner without the radius of curvature r. Although Figure 10 shows the results for optical combiners 3-1 to 3-4, similar results were obtained for optical combiners 1-1 to 1-4 and 2-1 to 2-4. It is being Here, the peak of the reciprocal of the radius of curvature r becomes larger as the curve is bent more, and becomes smaller as the curve is bent smaller.

Furthermore, the results shown in FIG. 11 show that in the optical combiner having the buffer section 50, the integral value of curvature is significantly smaller than in the optical combiner without the buffer section 50, regardless of the Young's modulus of the fixed section 30. I understand.

From the above, it can be seen that in the optical combiner having the buffer portion 50, the optical fiber 20 is less likely to be bent by the fixing portion 30 than in the optical combiner not having the buffer portion 50. Therefore, according to the optical combiner of the present invention, it is considered that deterioration in the quality of the output beam can be suppressed.

<Laser light source>
Next, an embodiment of the laser light source of the present invention will be described with reference to FIG. FIG. 12 is a schematic diagram showing an embodiment of the laser light source of the present invention.

As shown in FIG. 12, the laser light source 200 specifies light of a specific wavelength based on the light emitted from the optical combiner 100 and the optical fiber 21 of the optical fiber 20 of the second fiber structure 102 of the optical combiner 100. an optical resonator 201 that emits the laser beam as a laser beam, and excitation light sources D1 to D7 that input excitation light into each of the optical fiber strands 21 of the plurality of optical fibers 20 of the first fiber structure 101 of the optical combiner 100; It includes an output fiber 205 that outputs light emitted from the optical resonator 201 as a laser beam.

According to this laser light source 200, excitation light is incident on each of the optical fiber strands 21 of the plurality of optical fibers 20 of the first fiber structure 101 of the optical combiner 100 from the excitation light sources D1 to D7. Based on the light emitted from the optical fiber 21 of the optical fiber 20 of the second fiber structure 102, light of a specific wavelength is emitted from the optical resonator 201 as a laser beam, and this laser light is transmitted to the output fiber 205. is output from. At this time, as already mentioned, even if the optical combiner 100 is placed in an environment with large temperature changes, it is possible to suppress the deterioration in the quality of the beam output from the optical combiner 100. Therefore, even if the laser light source 200 is placed in an environment with large temperature changes, deterioration in the quality of the beam output from the laser light source 200 can be suppressed.

The excitation light sources D1 to D7 may be of any type as long as they emit excitation light, and for example, laser diodes or the like can be used as the excitation light sources D1 to D7.

The optical resonator 201 includes an amplifying optical fiber 202, a first reflecting section 203 provided at one end thereof, and a second reflecting section 204 provided at the other end. The first reflecting section 203 is connected to the optical fiber 20 of the second fiber structure 102 of the optical combiner 100, and the second reflecting section 204 is connected to the output fiber 205. In the optical resonator 201, spontaneous emission light is generated by the incident excitation light, and among the generated spontaneous emission light, light of a specific wavelength that is selectively reflected by the first reflection section 203 and the second reflection section 204 is transmitted. Stimulated emission of light occurs as a seed, and by repeating this stimulated emission, light of a specific wavelength is output as laser light.

The first reflecting section 203 and the second reflecting section 204 are composed of, for example, a fiber Bragg grating (FBG).

The amplification optical fiber 202 is composed of a rare earth element-doped optical fiber. Although the rare earth element is not particularly limited, for example, ytterbium (Yb) is used as the rare earth element.

Note that although the number of excitation light sources D1 to D7 is seven, it is not limited to seven. It can be changed as appropriate depending on the number of optical fibers 20 included in the first fiber structure 101 of the optical combiner 100.

<Laser device>
Next, an embodiment of the laser device of the present invention will be described with reference to FIG. 13. FIG. 13 is a schematic diagram showing an embodiment of the laser device of the present invention.

As shown in FIG. 13, the laser device 300 includes a plurality of laser light sources L1 to L7, an optical combiner 100 that combines and outputs laser light incident from the plurality of laser light sources L1 to L7, and a plurality of laser light sources L1 to L7. The output fiber 301 is connected to the optical fiber 20 of the two-fiber structure 102.

According to this laser device 300, laser beams from the plurality of laser light sources L1 to L7 are incident on the first fiber structure 101 of the optical combiner 100, combined, and emitted from the optical fiber 20 of the second fiber structure 102, This emitted light is output from the output fiber 301. At this time, as already mentioned, even if the optical combiner 100 is placed in an environment with large temperature changes, it is possible to suppress the deterioration in the quality of the beam output from the optical combiner 100. Therefore, even if the laser device 300 is placed in an environment with large temperature changes, it is possible to suppress deterioration in the quality of the beam output from the laser device 300.

In the laser device 300, the laser light sources L1 to L7 may be any laser light source, and examples of the laser light sources L1 to L7 include a laser diode, a CO ₂ laser, a YAG laser, the laser light source 200 described above, and the like. Can be mentioned. Among them, it is preferable that the laser light sources L1 to L7 include the laser light source 200 described above.

In this case, the laser light sources L1 to L7 are composed of the above-described laser light sources 200, and have an optical combiner 100 that can improve durability. Therefore, the laser device 300 can further improve its durability.

The present invention is not limited to the above embodiments. For example, in the above embodiment, the first fixing part 30 and the second fixing part 30 are bonded to the sealing part 40, but like the optical combiner 400 shown in FIG. 14, the first fixing part 30 and the second fixing part 30 may be spaced apart from the sealing part 40, respectively.

Further, in the embodiment described above, the sealing portion 40 is bonded to the main surface 11a of the base portion 11 and each of the two side wall portions 12, but it may not be bonded to the main surface 11a of the base portion 11. Alternatively, it may be spaced apart from the main surface 11a of the base portion 11. Alternatively, the sealing portion 40 may be bonded only to the main surface 11a of the base portion 11 and may not be bonded to the side wall portion 12.

Further, in the embodiment described above, the sealing part 40 may be omitted.

Furthermore, in the embodiment described above, the first fixing part 30 is provided so as to surround the first optical fiber part 101a, but the first fixing part 30 fixes the first optical fiber part 101a to the base of the support member 10. As long as it is fixed to each of the main surface 11a and the side wall portion 12 of the first optical fiber portion 11, it does not necessarily have to surround the first optical fiber portion 101a. Similarly, the second fixing section 30 does not necessarily surround the second optical fiber section 102a if the second optical fiber section 102a is fixed to each of the main surface 11a and the side wall section 12 of the base section 11 of the support member 10. You don't have to.

Furthermore, in the embodiment described above, the buffer portion 50 is provided directly on the main surface 11a of the base portion 11 of the support member 10, but a recess (not shown) is formed in the main surface 11a of the base portion 11, and A buffer portion 50 may be provided above the recess, and protrudes from the main surface 11a toward the first optical fiber portion 101a on the main surface 11a of the base portion 11, as in the optical combiner 500 shown in FIG. A protrusion 13 may be provided, and a buffer portion 50 may be provided on the protrusion 13. Among these, a protruding part 13 is provided on the main surface 11a of the base part 11 and protrudes from the main surface 11a toward the first optical fiber part 101a, and a buffer part 50 is provided on the protruding part 13. preferable. In this case, when the optical combiner 100 is placed in a high-temperature environment and the buffer part 50 is pressed and compressed by the first fixing part 30 as the first fixing part 30 expands, the base part 11 Compared to the case without the buffer part 50, the buffer part 50 can easily spread outward from the protrusion part 13, and the stress from the first fixing part 30 to the buffer part 50 can be easily relaxed. As a result, the fixed portion of the first optical fiber portion 101a becomes even more difficult to bend with respect to the position regulating portion of the first optical fiber portion 101a.

Further, a protrusion 13 that protrudes from the main surface 11a toward the second optical fiber portion 102a may be provided on the main surface 11a of the base portion 11, and a buffer portion 50 may be provided on the protrusion 13. . In this case, the fixed portion of the second optical fiber portion 102a also becomes even more difficult to bend with respect to the position regulating portion of the second optical fiber portion 102a. Therefore, deterioration in the quality of the beam output from the optical combiner 100 can be further suppressed.

The main surface of the protruding portion 13 on the buffer portion 50 side may be in contact with the entire surface of the buffer portion 50 on the base portion 11 side, or may be in contact with a part of the surface of the buffer portion 50 on the base portion 11 side. However, it is preferable to contact the entire surface of the buffer section 50 on the base section 11 side. In this case, the buffering effect of the buffer section 50 can be effectively exerted.

In addition, it is preferable that the buffer part 50 and the sealing part 40 are spaced apart. In this case, since a space is formed between the buffer part 50 and the sealing part 40, when the buffer part 50 is compressed by the first fixing part 30 or the second fixing part 30, the buffer part 50 moves into the space. As a result, the buffer section 50 can be easily compressed, and the buffering effect of the buffer section 50 can be more effectively exerted.

DESCRIPTION OF SYMBOLS 10...Supporting member 11...Base part 11a...Main surface 12...Side wall part 13...Protrusion part 21...Optical fiber strand 30...First fixing part, second fixing part 50...Buffer part 100,400,500...Optical combiner 101 ...First fiber structure 101a...First optical fiber section 102...Second fiber structure 102a...Second optical fiber section 200...Laser light source 201...Optical resonator 300...Laser device 301...Output fiber D1-D7...Excitation Light source L1 to L7...Laser light source

Claims (6)

An optical combiner comprising a first fiber structure and a second fiber structure,
The first fiber structure and the second fiber structure ,
an optical fiber section having a bare optical fiber;
a support member that supports the optical fiber section;
A fiber structure comprising a fixing part that fixes the optical fiber part to the support member,
The support member is
a base portion facing the optical fiber portion;
a side wall portion extending from the main surface of the base portion and facing the optical fiber portion;
The fixing part is made of a fiber structure, which is fixed to the main surface of the base part via a buffer part having a lower Young's modulus than the fixing part, and is also fixed to the side wall part,
In the first fiber structure, the optical fiber section has a plurality of the optical fiber strands,
In the second fiber structure, the optical fiber section has one optical fiber strand,
The end face of the optical fiber part of the first fiber structure and the end face of the optical fiber part of the second fiber structure are fusion-spliced,
An optical combiner, wherein the support member of the first fiber structure also serves as the support member of the second fiber structure. The optical combiner according to claim 1, wherein in the fiber structure, the ratio of the Young's modulus of the buffer section to the Young's modulus of the fixed section is 0.3 or less. In the fiber structure, the base part is provided between the main surface and the buffer part, and has a protrusion part that projects from the main surface toward the optical fiber part. optical combiner. The optical combiner according to any one of claims 1 to 3 ,
an optical resonator that emits light of a specific wavelength as a laser beam based on the light emitted from the optical fiber strand of the second fiber structure of the optical combiner;
an excitation light source that makes excitation light enter each of the plurality of optical fiber strands of the first fiber structure of the optical combiner;
A laser light source. multiple laser light sources;
an optical combiner that combines and emits laser light incident from the plurality of laser light sources,
A laser device, wherein the optical combiner comprises the optical combiner according to any one of claims 1 to 3 . The laser device according to claim 5 , wherein the laser light source is the laser light source according to claim 4 .

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