Laser device

Abstract

A laser device has a laser module that emits a plurality of lasers, a condensing lens that condenses the plurality of lasers, and an optical fiber that propagates the plurality of lasers. When viewed from an X-axis direction, positions of lasers on one side in a Z-axis direction with respect to a second reference line among the plurality of lasers arranged in the Z-axis direction are asymmetric about the second reference line from positions of lasers on the other side in the Z-axis direction with respect to the second reference line. A focal point distance of a fast-axis collimator lens is greater than a minimum value of each interval between the plurality of lasers.

Description

Technical Field

[0002] This disclosure relates to a laser device. Background Technology

[0003] Laser devices are known to have a laser source that emits multiple laser beams and an optical fiber (see, for example, Patent Document 1). In such a laser device, multiple laser beams emitted from the laser source are focused by a focusing lens and then incident on the optical fiber.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-114657 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In the aforementioned laser devices, a phenomenon known as backlighting sometimes occurs. When this backlighting is incident on the laser source, there is a concern about the degradation of the laser source. Furthermore, due to the precision requirements of such laser devices, their manufacture is difficult.

[0009] The purpose of this disclosure is to provide a laser device that can suppress the degradation of the laser source caused by backlighting and is easy to manufacture.

[0010] Technical means to solve the problem

[0011] One aspect of the laser device disclosed herein is, [1] "a laser device comprising: a laser module that emits a plurality of lasers arranged along a first direction toward a side of a second direction intersecting the first direction; a focusing lens having an optical axis parallel to the second direction and focusing the plurality of lasers; an optical fiber having an incident end face perpendicular to the optical axis of the focusing lens and propagating the plurality of lasers focused by the focusing lens; and a housing that houses the laser module and the focusing lens, the laser module having a plurality of laser units, each of the plurality of laser units comprising: a laser source emitting at least one of the plurality of lasers; a fast-axis collimating lens disposed in the optical path of the lasers and collimating the lasers emitted from the laser source in the fast-axis direction along the first direction; and a slow-axis collimating lens disposed relative to the fast-axis collimating lens." Positioned downstream of the optical path, the laser emitted from the fast-axis collimating lens is collimated in the slow-axis direction. When viewed from the second direction, the multiple intervals between the plurality of lasers emitted from the laser module in the state of arrangement along the first direction are non-uniform. When viewed from the second direction, the positions of at least one laser on one side of the reference line in the first direction and the positions of all lasers on the other side of the reference line in the first direction are asymmetrical about the reference line, which extends along a third direction intersecting both the first and second directions and passes through the optical axis of the condenser lens. The focal distance of the fast-axis collimating lens of each of the plurality of laser units is greater than the minimum value among the plurality of intervals.

[0012] In the laser device described above [1], when viewed from the second direction, the position of at least one laser on one side of the reference line relative to the reference line among the multiple lasers emitted from the laser module in the state of being arranged along the first direction is asymmetrical with respect to the reference line with respect to the reference line and the positions of all lasers on the other side of the reference line relative to the reference line in the first direction. Therefore, even if at least one laser on one side of the reference line relative to the reference line is reflected as a backlight at the incident end face of the optical fiber and incident on the laser source, the position of the backlight is not consistent with the position of the light-emitting area of ​​the laser source, thus suppressing the degradation of the laser source. Furthermore, the focal distance of the fast-axis collimating lens of each of the multiple laser units is greater than the minimum value among the multiple intervals between the multiple lasers emitted from the laser module in the state of being arranged along the first direction. Therefore, the distance between the laser source and the incident surface of the fast-axis collimating lens can be increased, thus making it easier to install the fast-axis collimating lens relative to the laser source. Therefore, it is easy to manufacture the laser device. Thus, according to this laser device, it is possible to suppress the degradation of the laser source caused by backlight and manufacturing becomes easier.

[0013] One aspect of the laser device disclosed herein may also be, [2] "a laser device as described in [1] above, wherein, when viewed from the second direction, the positions of all lasers emitted from the laser module in a state arranged along the first direction that are located on one side of the reference line in the first direction are asymmetrical with respect to the reference line with respect to the other side of the reference line in the first direction." This allows for more reliable suppression of laser source degradation caused by backlighting.

[0014] One aspect of the laser device disclosed herein may also be, [3] "a laser device as described in [1] or [2] above, wherein the laser module further comprises: a support body comprising a plurality of mounting surfaces arranged in a stepped manner such that the position of the plurality of mounting surfaces is higher in the first direction the further away from the condenser lens in the second direction, the laser light source of each of the plurality of laser units is disposed on each of the plurality of mounting surfaces and emits the laser towards the third direction, each of the plurality of laser units further comprises: a reflector disposed downstream of the optical path relative to the slow-axis collimating lens and reflects the laser emitted from the slow-axis collimating lens towards the condenser lens side in the second direction, the reflector of each of the plurality of laser units being arranged along the second direction when viewed from the first direction and including a reflective surface overlapping the laser light source when viewed from the third direction." Thus, by adjusting the position of each mounting surface in the first direction, the asymmetric state of the position of at least one laser relative to the reference line on one side of the first direction and the positions of all lasers relative to the reference line on the other side of the first direction can be adjusted.

[0015] One aspect of the laser device disclosed herein may also be, [4] "the laser device as described in any one of [1] to [3] above, wherein it further comprises: a wavelength filter disposed between the plurality of laser units and the optical fiber, allowing the plurality of lasers emitted from the plurality of laser units to pass through and reflecting light emitted from the optical fiber." Thus, it is possible to suppress light incident from outside the housing into the housing via the optical fiber onto each laser unit.

[0016] The laser device of one aspect of this disclosure may also be, [5] "the laser device as described in any one of [1] to [4] above, wherein the focal distance of the fast-axis collimating lens is 100 μm to 400 μm." Thus, as described above, the mounting of the fast-axis collimating lens relative to the laser source becomes easier, thereby making the manufacture of the laser device easier.

[0017] The laser device of one aspect of this disclosure may also be, [6] "the laser device as described in any one of [1] to [5] above, wherein the plurality of intervals are 100 μm to 500 μm respectively." Thus, as described above, the mounting of the fast-axis collimating lens relative to the laser source becomes easier, thereby facilitating the manufacture of the laser device.

[0018] The laser device of one aspect of this disclosure may also be, [7] "the laser device as described in any one of [1] to [5] above, wherein the difference between each of the plurality of intervals is 700 μm or less." Thus, the aforementioned asymmetric state can be achieved.

[0019] One aspect of the laser device disclosed herein may also be, [8] "the laser device as described in any one of [1] to [7] above, wherein, when viewed from the second direction, the distance from the nth laser (n is a natural number) located on the side of the first direction relative to the reference line to the reference line is 10 μm to 500 μm, and the distance from the nth laser located on the other side of the first direction relative to the reference line to the reference line is 10 μm to 500 μm." Thus, it is possible to suppress the light-emitting region of the laser source from which the nth laser located on the side of the first direction relative to the reference line, after being reflected at the incident end face of the optical fiber, is incident as backlight onto the nth laser located on the other side of the first direction relative to the reference line. Similarly, it is possible to suppress the light-emitting region of the laser source from which the nth laser located on the other side of the first direction relative to the reference line, after being reflected at the incident end face of the optical fiber, is incident as backlight onto the nth laser located on the side of the first direction relative to the reference line. Therefore, it is possible to suppress laser source degradation caused by backlight.

[0020] The laser device of one aspect of this disclosure may also be, [9] "the laser device as described in any one of [1] to [8] above, wherein each of the plurality of laser units has a laser diode strip, the laser diode strip comprising a plurality of light-emitting regions." Thus, it is possible to suppress the degradation of the laser source while maintaining the light output of the laser source.

[0021] One aspect of the laser device disclosed herein may also be,

[10] "the laser device as described in any one of [1] to [8] above, wherein each of the plurality of laser units has a plurality of semiconductor laser elements, each of the plurality of semiconductor laser elements comprising a light-emitting region." Thus, it is possible to suppress the degradation of the laser source while maintaining the light output of the laser source.

[0022] The effects of the invention

[0023] According to this disclosure, a laser device that can suppress laser source degradation caused by backlighting and is easy to manufacture can be provided. Attached Figure Description

[0024] Figure 1 This is a top view of the laser device according to the first embodiment.

[0025] Figure 2 It is along Figure 1 A cross-sectional view of line II-II.

[0026] Figure 3 yes Figure 1 The top view of the support shown.

[0027] Figure 4 yes Figure 1 The front view of the support shown.

[0028] Figure 5 yes Figure 1 A magnified view of a portion of the image.

[0029] Figure 6 It is along Figure 5 A cross-sectional view of the VI-VI line.

[0030] Figure 7 yes Figure 5 The image shows a front view of the laser source.

[0031] Figure 8 yes Figure 5 The image shows a side view of the laser source and the fast-axis collimating lens.

[0032] Figure 9 yes Figure 5 The top view of the slow-axis collimating lens and the reflecting mirror shown.

[0033] Figure 10 yes Figure 1 The image shows a front view of the laser module.

[0034] Figure 11 yes Figure 1 The image shows a side view of the laser module.

[0035] Figure 12 From Figure 2 The front view of the condenser lens when viewed from the imaginary surface shown.

[0036] Figure 13 From Figure 2 The front view of the condenser lens when viewed from the imaginary surface shown.

[0037] Figure 14 This is a schematic diagram representing multiple laser beams and multiple backlight beams.

[0038] Figure 15 This is a schematic diagram showing the positional relationship between multiple luminous areas and multiple reflective areas.

[0039] Figure 16 This is a front view of the laser source according to the second embodiment.

[0040] Figure 17 This is a top view of the laser unit according to the second embodiment.

[0041] Figure 18 This is a schematic diagram illustrating the adjustment of the arrangement direction of the plurality of lasers in the second embodiment.

[0042] Figure 19 This is a front view of a modified laser source. Detailed Implementation

[0043] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same or equivalent parts are labeled with the same reference numerals, and repeated descriptions are omitted.

[0044] [First Implementation Method]

[0045] [Structure of the laser device]

[0046] like Figure 1 As shown, the laser device 1 of the first embodiment includes a laser module 2, a focusing lens 3, an optical fiber component 4, a wavelength filter 5, a housing 6, and electrodes 7. The laser device 1 is used, for example, for the excitation of a fiber laser. The laser module 2, the focusing lens 3, and the wavelength filter 5 are housed in the housing 6.

[0047] Laser module 2 emits multiple laser beams. A condenser lens 3 is positioned downstream of the laser module 2 in the optical path of the multiple laser beams. The condenser lens 3 is separate from the laser module 2. The condenser lens 3 has an optical axis 3a parallel to the X-axis direction. The condenser lens 3 focuses the multiple laser beams emitted from the laser module 2. The diameter of the condenser lens 3 is, for example, about 5 mm. That is, the width of the condenser lens 3 in the Z-axis direction is, for example, about 5 mm. The material of the condenser lens 3 is, for example, glass. The refractive index of the condenser lens 3 is, for example, 1.6 to 2.0. In this embodiment, the refractive index of the condenser lens 3 is, for example, about 1.8. As the condenser lens 3, a plano-convex lens (product model: N-LA SF44) manufactured by Edmund Optics is used, for example.

[0048] The fiber optic component 4 is positioned downstream of the optical path of the multiple lasers relative to the condenser lens 3. The fiber optic component 4 has an optical fiber 46. The optical fiber 46 propagates the multiple lasers focused by the condenser lens 3.

[0049] A wavelength filter 5 is disposed in the optical path between the laser module 2 and the optical fiber 46. In this embodiment, the wavelength filter 5 is disposed in the optical path between the laser module 2 and the condenser lens 3. That is, the wavelength filter 5 is separate from both the laser module 2 and the condenser lens 3. The wavelength filter 5 allows multiple laser beams (excitation light) emitted from the laser module 2 to pass through. The wavelength filter 5 reflects oscillating light having a different wavelength than the excitation light. The wavelength filter 5 reflects light incident from outside the housing 6 into the housing 6 via the optical fiber 46 (light emitted from the optical fiber 46, i.e., light having a different wavelength than the laser beam emitted from the laser module 2). The wavelength filter 5 is, for example, a dichroic mirror.

[0050] Electrode 7 is fixed relative to housing 6. Laser module 2 is driven by voltage supplied via electrode 7.

[0051] like Figure 1 and Figure 2 As shown, the housing 6 has a bottom wall 61, a side wall 62, a connecting member 63, and a supporting member 64. The bottom wall 61 is, for example, plate-shaped. The side wall 62 is fixed to the main surface of the bottom wall 61. The laser module 2, the condenser lens 3, and the wavelength filter 5 are fixed to the main surface of the bottom wall 61, respectively, with their arrangement inside the side wall 62. The condenser lens 3 and the wavelength filter 5 are, for example, fixed to the bottom wall 61 by adhesive resin.

[0052] The sidewall 62 includes an inner wall surface 62a, an outer wall surface 62b, and a through hole 62c. The through hole 62c penetrates the sidewall 62. The through hole 62c has an axis, for example, parallel to the X-axis direction. The connecting member 63 is, for example, cylindrical. The front end 63a of the connecting member 63 is fixed to the outer wall surface 62b of the sidewall 62 with the axis of the connecting member 63 aligned with the axis of the through hole 62c.

[0053] The support member 64 is, for example, plate-shaped. The support member 64 is fixed to the inner wall surface 62a of the sidewall 62. When viewed from the X-axis direction, the support member 64 partially overlaps with the through hole 62c of the sidewall 62. The support member 64 includes a support surface 64a. The support surface 64a is, for example, a flat surface intersecting the Z-axis direction. The position of the support surface 64a in the Z-axis direction is approximately consistent with the position of the axis of the connecting member 63 in the Z-axis direction. The material of the housing 6 is, for example, copper or copper-tungsten.

[0054] The fiber optic component 4 is connected to the housing 6. Specifically, the fiber optic component 4 has a ferrule 45 for holding the fiber optic cable 46. The ferrule 45 is, for example, cylindrical. The ferrule 45 is inserted into the connecting component 63 from the rear end 63b of the connecting component 63. The fiber optic cable 46 is inserted into the insertion hole of the ferrule 45. The front end of the fiber optic cable 46 is placed on the support surface 64a of the supporting component 64 inside the sidewall 62. The front end of the fiber optic cable 46 is fixed to the support surface 64a, for example, by UV-cured resin. The fiber optic cable 46 has an incident end face 46a perpendicular to the optical axis 3a of the condenser lens 3. Multiple laser beams focused by the condenser lens 3 are incident on the incident end face 46a.

[0055] [Structure of the laser module]

[0056] like Figure 1 As shown, laser module 2 has a support body 30 and multiple laser units 40A, 40B, 40C, and 40D. Figure 3 and Figure 4 As shown, the support body 30 is, for example, rectangular when viewed from the Z-axis direction (the thickness direction of the support body 30). The support body 30 includes a bottom surface 31 and a main surface 32. The bottom surface 31 is a flat surface parallel to the XY plane. The main surface 32 faces the opposite side to the bottom surface 31. The main surface 32 is stepped. Specifically, the main surface 32 includes a first region 33 and a second region 34. The first region 33 and the second region 34 are arranged along the Y-axis direction when viewed from the Z-axis direction. The first region 33 and the second region 34 are, for example, rectangular.

[0057] The first region 33 includes a base surface 33e, a first mounting surface 33a, a second mounting surface 33b, a third mounting surface 33c, and a fourth mounting surface 33d. The base surface 33e is a flat surface parallel to the XY plane. The base surface 33e is, for example, rectangular. When viewed from the Z direction, the first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are located on opposite sides of the second region 34 relative to the base surface 33e. The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are all flat surfaces parallel to the XY plane. Each of the first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d is, for example, rectangular.

[0058] The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are arranged along the X-axis direction when viewed from the Z-axis direction. The positions of the first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d in the Z-axis direction are different from each other. The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are arranged in a stepped manner from one side of the support 30 in the X-axis direction towards the other side. The first mounting surface 33a, the second mounting surface 33b, the third mounting surface 33c, and the fourth mounting surface 33d are arranged such that the further away from the condenser lens 3 (see reference 3) in the X-axis direction... Figure 1 (The surfaces are arranged in a stepped manner, with the condenser lens 3 facing the opposite side of the fiber optic component 4), increasing in position along the Z-axis. Specifically, the position of the first mounting surface 33a in the Z-axis direction coincides with the position of the base surface 33e in the Z-axis direction. That is, the first mounting surface 33a lies on the same plane as the base surface 33e. The second mounting surface 33b is located on the opposite side of the base surface 31 relative to the first mounting surface 33a. The third mounting surface 33c is located on the opposite side of the base surface 31 relative to the second mounting surface 33b. The fourth mounting surface 33d is located on the opposite side of the base surface 31 relative to the third mounting surface 33c.

[0059] The height difference H2 between the second mounting surface 33b and the third mounting surface 33c in the Z-axis direction is different from the height difference H1 between the first mounting surface 33a and the second mounting surface 33b in the Z-axis direction, and the height difference H3 between the third mounting surface 33c and the fourth mounting surface 33d in the Z-axis direction. In this embodiment, the height difference H2 is smaller than both the height difference H1 and the height difference H3. In this embodiment, the height difference H1 and the height difference H3 are the same as each other.

[0060] The second region 34 is a flat surface parallel to the XY plane. The second region 34 is more concave than the first region 33. That is, the second region 34 is located on the side of the bottom surface 31 relative to the first region 33. The second region 34 is located between the base surface 33e and the bottom surface 31 in the Z-axis direction. The distance between the bottom surface 31 and the base surface 33e is greater than the distance between the bottom surface 31 and the second region 34. In other words, the thickness of the portion of the support 30 containing the first region 33 is greater than the thickness of the portion of the support 30 containing the second region 34.

[0061] A mounting hole 33f is formed on the base surface 33e. The mounting hole 33f, for example, penetrates the support body 30. The mounting hole 33f is, for example, circular when viewed from the Z-axis direction. Laser light sources 41A, 41B, 41C, and 41D (see reference) are mounted in the mounting hole 33f. Figure 10 The support body 30 is positioned by a clamp (e.g., a spacer). The material of the support body 30 is, for example, copper (Cu) or copper-tungsten (CuW). The support body 30 is fixed to the bottom wall 61 of the housing 6, for example, by solder material.

[0062] The support body 30 supports multiple laser units 40A, 40B, 40C, and 40D. The multiple laser units 40A, 40B, 40C, and 40D are fixed relative to the support body 30. Specifically, as follows... Figure 5 and Figure 6 As shown, the laser unit 40A is disposed on the main surface 32 of the support 30. The laser unit 40A includes a laser source 41A, a fast-axis collimating lens 42A, a slow-axis collimating lens 44A, and a reflector 50A. The laser source 41A, the fast-axis collimating lens 42A, the slow-axis collimating lens 44A, and the reflector 50A are arranged sequentially along the Y-axis when viewed from the Z-axis direction.

[0063] A laser source 41A is disposed on the first mounting surface 33a of the support 30. The laser source 41A is fixed relative to the support 30. Specifically, the laser source 41A includes a submount 411 and a semiconductor laser element 412. The submount 411 is disposed on the first mounting surface 33a. The submount 411 includes, for example, a substrate formed of aluminum nitride (AlN) and a metal film (e.g., Cu or Ni / Au) metallized on the surface of the substrate. The metal film functions, for example, for soldering or conduction. The submount 411 is fixed to the first mounting surface 33a, for example, by solder material. The semiconductor laser element 412 is disposed on the opposite side of the first mounting surface 33a relative to the submount 411. The semiconductor laser element 412 is fixed to the submount 411, for example, by solder material. In this embodiment, the semiconductor laser element 412 emits a laser beam La.

[0064] A fast-axis collimating lens 42A is disposed in the optical path of the laser La. The fast-axis collimating lens 42A is disposed on the base surface 33e of the support 30. In this embodiment, the fast-axis collimating lens 42A is fixed to the sub-base 411 by fixing members 49A. The fixing members 49A are provided at both ends of the fast-axis collimating lens 42A in the X-axis direction between the fast-axis collimating lens 42A and the sub-base 411. When viewed from the Z-axis direction, the fixing members 49A are located on both sides of the semiconductor laser element 412 in the X-axis direction. There is a gap between the fast-axis collimating lens 42A and the laser source 41A. The fixing member 49A is, for example, a UV-curable resin. The fast-axis collimating lens 42A collimates the laser La emitted from the laser source 41A in the fast-axis direction (first direction) along the Z-axis.

[0065] The slow-axis collimating lens 44A is disposed downstream of the laser La in the optical path relative to the fast-axis collimating lens 42A. The slow-axis collimating lens 44A is disposed on the second region 34 of the support 30. The slow-axis collimating lens 44A is fixed relative to the support 30. The slow-axis collimating lens 44A is fixed to the second region 34, for example, by adhesive resin 440. The adhesive resin 440 is located on the bottom surface 31 side of the first region 33. The slow-axis collimating lens 44A collimates the laser La emitted from the fast-axis collimating lens 42A in the slow-axis direction along the X-axis (a second direction intersecting the first direction).

[0066] Reflector 50A is positioned downstream of the slow-axis collimating lens 44A in the optical path of laser La. Reflector 50A is positioned between the slow-axis collimating lens 44A and the condenser lens 3 (see reference). Figure 1 The optical path between the two regions is defined. A reflector 50A is disposed on the second region 34. The reflector 50A is fixed relative to the support 30. The reflector 50A is fixed to the second region 34, for example, by an adhesive resin 500. The adhesive resin 500 is located on the side closer to the bottom surface 31 than the first region 33.

[0067] like Figure 7 and Figure 8 As shown, the semiconductor laser element 412 includes a light emitting surface 41b. The light emitting surface 41b is, for example, a flat surface parallel to the XZ plane. The light emitting surface 41b is, for example, located on the same plane as the front end surface 41c of the sub-base 411. The light emitting surface 41b includes a light-emitting region 41a. Laser La is emitted from the light-emitting region 41a. The semiconductor laser element 412 emits laser La towards the Y-axis direction (a third direction intersecting both the first and second directions) on one side (the fast-axis collimating lens 42A side). Laser La is, for example, diffuse light. Laser La diffuses in a conical shape away from the laser source 41A and travels along the Y-axis direction. Laser La uses the Z-axis direction as the fast axis direction and the X-axis direction as the slow axis direction.

[0068] The fast-axis collimating lens 42A is, for example, a cylindrical lens with the Z-axis direction as the collimation direction. The fast-axis collimating lens 42A extends along the X-axis direction. The fast-axis collimating lens 42A is, for example, formed of high-refractive-index glass. The refractive index of the fast-axis collimating lens 42A is, for example, 1.6 to 2.0. In this embodiment, as the fast-axis collimating lens 42A, an FAC lens (J10919 series) manufactured by Hamamatsu Photonics Co., Ltd. is used, for example.

[0069] The fast-axis collimating lens 42A includes an incident surface 421 opposite to the light-emitting region 41a of the laser source 41A, and an exit surface 422 facing the opposite side of the incident surface 421. The incident surface 421 is, for example, a flat surface parallel to the XZ plane. The exit surface 422 is a convex surface protruding to the opposite side of the incident surface 421. The exit surface 422 is part of a cylindrical surface having an axis parallel to the X-axis direction. The laser La, which diffuses in a conical shape, is incident on the incident surface 421 and collimated (parallelized) in the Z-axis direction by the fast-axis collimating lens 42A, and then exits from the exit surface 422 as light, for example, parallel to the XY plane. The focal point of the fast-axis collimating lens 42A is located at the light exit surface 41b of the semiconductor laser element 412. The focal distance Fd of the fast-axis collimating lens 42A is, for example, 100 μm to 400 μm.

[0070] like Figure 9 As shown, the slow-axis collimating lens 44A is, for example, a cylindrical lens with the X-axis as the collimating direction. The slow-axis collimating lens 44A extends along the Z-axis. The slow-axis collimating lens 44A is, for example, formed of high-refractive-index glass. The refractive index of the slow-axis collimating lens 44A is, for example, 1.6 to 2.0. In this embodiment, the slow-axis collimating lens 44A is, for example, the SAC5600 (product model: K-PBK40) from FISBA Corporation.

[0071] The slow-axis collimating lens 44A includes an incident surface 441 opposite to the laser source 41A and an exit surface 442 facing the opposite side of the incident surface 441. The incident surface 441 is, for example, a flat surface parallel to the XZ plane. The exit surface 442 is a convex surface protruding to the opposite side of the incident surface 441. The exit surface 442 is part of a cylindrical surface having an axis parallel to the Z-axis direction. The laser La incident on the incident surface 441 is collimated (parallelized) in the X-axis direction by the slow-axis collimating lens 44A and exits from the exit surface 442 as, for example, parallel light (collimated light) in the Y-axis direction. The focal distance of the slow-axis collimating lens 44A is, for example, about 5.6 mm.

[0072] Reflector 50A directs the laser La emitted from slow-axis collimating lens 44A along the X-axis towards condenser lens 3 (see reference). Figure 1 Side reflection. The reflector 50A includes a reflecting surface 51 that is obliquely opposite to the slow-axis collimating lens 44A. The reflecting surface 51 is parallel to the Z-axis and obliquely intersects the X-axis and Y-axis, respectively. When viewed from the Z-axis, the reflecting surface 51 is obliquely inclined as it moves away from the slow-axis collimating lens 44A and closer to the condenser lens 3 along the Y-axis. When viewed from the Y-axis, the reflecting surface 51 overlaps with the laser source 41A.

[0073] In this embodiment, "along the direction" includes both a manner parallel to the direction and a manner intersecting the direction at a predetermined angle. The predetermined angle, for example, is 0 to 30 degrees. In this embodiment, the reflector 50A can reflect the laser La emitted from the slow-axis collimating lens 44A in a manner that allows the laser La to travel along an optical path parallel to the X-axis direction, or it can reflect the laser La emitted from the slow-axis collimating lens 44A in a manner that allows the laser La to travel along an optical path intersecting the X-axis direction at the aforementioned predetermined angle.

[0074] like Figure 10 As shown, multiple laser units 40A, 40B, 40C, and 40D are arranged along the X-axis. Laser unit 40B, like laser unit 40A, includes a laser source 41B, a fast-axis collimating lens 42B, a slow-axis collimating lens 44B, and a reflector 50B. Laser unit 40B differs from laser unit 40A in that the laser source 41B is positioned on a second mounting surface 33b. Laser unit 40C, like laser unit 40A, includes a laser source 41C, a fast-axis collimating lens 42C, a slow-axis collimating lens 44C, and a reflector 50C. Laser unit 40C differs from laser unit 40A in that the laser source 41C is positioned on a third mounting surface 33c. Laser unit 40D, like laser unit 40A, includes a laser source 41D, a fast-axis collimating lens 42D, a slow-axis collimating lens 44D, and a reflector 50D. The laser unit 40D differs from the laser unit 40A in that the laser source 41D is disposed on the fourth mounting surface 33d.

[0075] The structures of laser sources 41B, 41C, and 41D are the same as those of laser source 41A. The structures of fast-axis collimating lenses 42B, 42C, and 42D are the same as those of fast-axis collimating lens 42A. The structures of slow-axis collimating lenses 44B, 44C, and 44D are the same as those of slow-axis collimating lens 44A.

[0076] Multiple reflectors 50A, 50B, 50C, and 50D are arranged along the X-axis when viewed from the Z-axis direction. This structure helps to suppress the enlargement of the laser device 1. The height (length in the Z-axis direction) of reflector 50B is greater than the height of reflector 50A. The end 50b of reflector 50B opposite to the support 30 is located further away from the support 30 than the end 50a of reflector 50A opposite to the support 30. The difference between the height of reflector 50B and the height of reflector 50A is approximately the same as the difference between the height of the second mounting surface 33b and the height of the first mounting surface 33a. The height of reflector 50C is greater than the height of reflector 50B. The end 50c of reflector 50C opposite to the support 30 is located further away from the support 30 than the end 50b of reflector 50B opposite to the support 30. The height difference between reflector 50C and reflector 50B is approximately the same as the height difference between the third mounting surface 33c and the second mounting surface 33b. Reflector 50D is taller than reflector 50C. The end 50d of reflector 50D opposite to the support 30 is positioned further from the support 30 than the end 50c of reflector 50C opposite to the support 30. The height difference between reflector 50D and reflector 50C is approximately the same as the height difference between the fourth mounting surface 33d and the third mounting surface 33c. The structures of reflectors 50B, 50C, and 50D are identical to those of reflector 50A, except for their height.

[0077] like Figure 11 As shown, laser La exits from slow-axis collimating lens 44A and is reflected by mirror 50A. Similarly, laser Lb exits from slow-axis collimating lens 44B and is reflected by mirror 50B. Laser Lb is reflected at a position opposite to mirror 50A on the support 30. That is, laser Lb does not pass through mirror 50A. Similarly, laser Lc exits from slow-axis collimating lens 44C and is reflected by mirror 50C. Laser Lc is reflected at a position opposite to mirror 50B on the support 30. That is, laser Lc does not pass through mirrors 50B and 50A. Similarly, laser Ld exits from slow-axis collimating lens 44D and is reflected by mirror 50D. Laser Ld is reflected at a position opposite to mirror 50C on the support 30. That is, laser Ld does not pass through mirrors 50C, 50B, and 50A. As described above, laser module 2 emits multiple lasers La, Lb, Lc, and Ld arranged along the Z-axis direction (first direction) to one side (the side of condenser lens 3) in the X-axis direction (second direction). Lasers La, Lb, Lc, and Ld, arranged along the Z-axis direction, emit light towards condenser lens 3 (refer to...). Figure 1 (Incident)

[0078] After focusing the laser beams La, Lb, Lc, and Ld by the focusing lens 3, it directs them toward the fiber optic component 4 (see reference). Figure 1 ) fiber optic 46 coupling.

[0079] [Laser location]

[0080] Figure 12 From Figure 2 The image shows a front view of the condenser lens 3 when viewed through the imaginary plane S. The imaginary plane S is a plane perpendicular to the optical axis 3a of the condenser lens 3. Figure 12 As shown, the condenser lens 3 has a first reference line 3b extending along the Z-axis and passing through the optical axis 3a, and a second reference line 3c extending along the Y-axis and passing through the optical axis 3a. In this embodiment, the first reference line 3b is parallel to the Z-axis direction, and the second reference line 3c is parallel to the Y-axis direction.

[0081] The centers Lac (La), Lbc (Lb), Lcc (Lc), and Ldc (Ld) of lasers are each located on the first reference line 3b. Lasers La, Lb, Lc, and Ld are located on one side of the Z-axis (…). Figure 12 The middle side is the bottom side, facing the other side in the Z-axis direction ( Figure 12 (The lasers are arranged in order, with the center at the top). Lasers La and Lb are located on one side relative to the second reference line 3c, while lasers Lc and Ld are located on the other side relative to the second reference line 3c. The distance between adjacent centers Lac, Lbc, Lcc, and Ldc is, for example, approximately 0.4 mm.

[0082] The cross-sectional shape of laser La on the YZ plane (the plane perpendicular to the optical axis 3a) is described. The outer edge of laser La is, for example, elliptical. The outer edge of laser La has a minor axis parallel to the first reference line 3b and a major axis parallel to the second reference line 3c. The intensity distribution of laser La follows, for example, a normal distribution (Gaussian distribution). Specifically, the intensity of laser La decreases normally with respect to the center Lac. The intensity at the outer edge of laser La is 1 / e of the intensity at the center Lac. 2 In other words, in this embodiment, the outer edge of the laser La has an intensity that is 1 / e of the intensity at the center Lac. 2 The laser is formed as an ellipse. The width of the laser La in the Z-axis direction is, for example, about 0.3 mm. The width of the laser La in the Z-axis direction is, for example, the length of the line segment connecting the two intersection points of the first reference line 3b and the outer edge of the laser La. In addition, the cross-sectional shapes of the lasers Lb, Lc, and Ld on the YZ plane are the same as the cross-sectional shape of the laser La.

[0083] When viewed from the X-axis direction, the position of at least one laser among the plurality of lasers La, Lb, Lc, and Ld emitted from the laser module 2 in a Z-axis orientation, positioned relative to the second reference line 3c on one side of the Z-axis, is asymmetrical with respect to the second reference line 3c compared to the positions of all lasers on the other side of the Z-axis relative to the second reference line 3c. In this embodiment, when viewed from the X-axis direction, the positions of all lasers among the plurality of lasers La, Lb, Lc, and Ld emitted from the laser module 2 in a Z-axis orientation, positioned relative to the second reference line 3c on one side of the Z-axis, are asymmetrical with respect to the second reference line 3c compared to the positions of all lasers on the other side of the Z-axis relative to the second reference line 3c.

[0084] When viewed from the X-axis direction, the distance from the nth laser (n is a natural number) to the second reference line 3c is different from the distance from the laser on the other side of the Z-axis relative to the second reference line 3c.

[0085] In this embodiment, the positions of laser La and laser Ld are asymmetrical about the second reference line 3c. The first distance R1 from the center Lac of laser La (the second laser La counting from the second reference line 3c) to the second reference line 3c is different from the fourth distance R4 from the center Ldc of laser Ld (the second laser counting from the second reference line 3c) to the second reference line 3c. The first distance R1 is, for example, smaller than the fourth distance R4. The difference between the first distance R1 and the fourth distance R4 is, for example, 10 μm to 500 μm.

[0086] In this embodiment, the positions of laser Lb and laser Lc are asymmetrical about the second reference line 3c. The second distance R2 from the center Lbc of laser Lb (the first laser counting from the second reference line 3c) to the second reference line 3c is different from the third distance R3 from the center Lcc of laser Lc (the first laser counting from the second reference line 3c) to the second reference line 3c. The second distance R2 is, for example, smaller than the third distance R3. The difference between the second distance R2 and the third distance R3 is, for example, 10 μm to 500 μm.

[0087] In this embodiment, the positions of laser La and laser Lc are asymmetrical about the second reference line 3c. The first distance R1 and the third distance R3 are different from each other. For example, the first distance R1 is greater than the third distance R3.

[0088] In this embodiment, the positions of laser Lb and laser Ld are asymmetrical about the second reference line 3c. The second distance R2 and the fourth distance R4 are different from each other. For example, the second distance R2 is smaller than the fourth distance R4.

[0089] When viewed from the X-axis, lasers La, Lb, Lc, and Ld are arranged at non-uniform intervals along the Z-axis. The intervals between multiple lasers La, Lb, Lc, and Ld are also non-uniform when viewed from the X-axis. The "interval" between lasers refers to the shortest distance between adjacent lasers. For example, the "interval" between lasers can be the length of the region between the outer edges of one laser and the outer edges of another in a line segment connecting the centers of adjacent lasers.

[0090] Multiple intervals being "non-uniform" means that at least two of the multiple intervals are different from each other. The first interval G1 between lasers La and Lb along the Z-axis, the second interval G2 between lasers Lb and Lc along the Z-axis, and the third interval G3 between lasers Lc and Ld along the Z-axis are non-uniform. In this embodiment, the first interval G1 is greater than the second interval G2. In this embodiment, the second interval G2 is smaller than the third interval G3. In this embodiment, the first interval G1 and the third interval G3 are the same as each other.

[0091] The focal distance Fd of the fast-axis collimating lens 42A is greater than the minimum value among the first interval G1, the second interval G2, and the third interval G3. The focal distance Fd of the fast-axis collimating lens 42A is greater than the second interval G2. In this embodiment, the focal distance Fd of the fast-axis collimating lens 42A is greater than any one of the first interval G1, the second interval G2, and the third interval G3. The first interval G1, the second interval G2, and the third interval G3 are each, for example, 100 μm to 500 μm. The difference between each of the first interval G1, the second interval G2, and the third interval G3 is, for example, 700 μm or less. Specifically, the difference between the first interval G1 and the second interval G2, and the difference between the third interval G3 and the second interval G2, are each, for example, 700 μm or less.

[0092] "The positions of the two lasers are asymmetrical" refers to a situation where, on a cross-section perpendicular to the optical axis of the condenser lens, when one laser is rotated 180 degrees around the optical axis of the condenser lens, there exists a region within one laser that does not overlap with the other. As an example, in this embodiment, such as... Figure 13 As shown, the imaginary laser Lbs, formed by rotating laser Lb 180 degrees around the optical axis 3a, separates from laser Lc. Therefore, it can be said that there exists a region in the imaginary laser Lbs that does not overlap with laser Lc. In this case, it can be said that the positions of laser Lb and laser Lc are asymmetrical about the second reference line 3c. As a second example, for instance... Figure 13 Even if a portion of the hypothetical laser Lbs overlaps with laser Lc, it can be said that there exists a region in the hypothetical laser Lbs that does not overlap with laser Lc. In this case, it can also be said that the positions of laser Lb and laser Lc are asymmetrical about the second reference line 3c.

[0093] "The positions of the two lasers are asymmetrical" refers to the situation where, on a cross-section perpendicular to the optical axis of the condenser lens, the distance from the center of one laser to the reference line is different from the distance from the center of the other laser to the reference line. As a third example, in this embodiment, such as... Figure 12 As shown, the second distance R2 from the center Lbc of laser Lb to the second reference line 3c is different from the third distance R3 from the center Lcc of laser Lc to the second reference line 3c. Therefore, it can be said that the position of laser Lb and the position of laser Lc are asymmetrical about the second reference line 3c.

[0094] like Figure 14 As shown, there are cases where each laser La, Lb, Lc, and Ld is reflected at the incident end face 46a of the optical fiber 46 and then incident as backlight through the condenser lens 3 onto each laser source 41A, 41B, 41C, and 41D of the laser module 2.

[0095] After being reflected at the incident end face 46a, the laser La is incident on the laser module 2 as a return beam Lar via the focusing lens 3. As mentioned above, the position of the laser La is asymmetrical about the second reference line 3c with respect to the positions of lasers Lc and Ld. Therefore, the return beam Lar travels on a different optical path than the optical paths of lasers Lc and Ld. The optical path of the return beam Lar is located between the optical paths of lasers Lc and Ld.

[0096] After being reflected at the incident end face 46a, laser Lb is incident on laser module 2 as a return beam Lbr via condenser lens 3. As mentioned above, the position of laser Lb is asymmetrical about the second reference line 3c with respect to the positions of lasers Lc and Ld. Therefore, the return beam Lbr travels on a different optical path than the optical paths of lasers Lc and Ld. The optical path of the return beam Lbr lies between the optical path of laser Lc and the optical axis 3a of condenser lens 3.

[0097] After being reflected at the incident end face 46a, laser Lc is incident on laser module 2 as a return beam Lcr via condenser lens 3. As mentioned above, the position of laser Lc is asymmetrical about the second reference line 3c with respect to the positions of lasers La and Lb. Therefore, the return beam Lcr travels on a different optical path than the optical paths of lasers La and Lb. The optical path of the return beam Lcr lies between the optical paths of laser La and laser Lb.

[0098] After being reflected at the incident end face 46a, laser Ld is incident on laser module 2 as a return light Ldr via condenser lens 3. As mentioned above, the position of laser Ld is asymmetrical with respect to the second reference line 3c and the positions of lasers La and Lb. Therefore, the return light Ldr travels on a different optical path than the optical paths of lasers La and Lb. The optical path of the return light Ldr is located on the opposite side of the optical axis 3a of condenser lens 3 relative to the optical path of laser La.

[0099] like Figure 15 As shown in (a), in this embodiment, the reflected light Lar is incident on a region of the laser source 41D that does not overlap with the light-emitting region 41a. Figure 15 As shown in (b), in this embodiment, the reflected light Lbr is incident on a region of the laser source 41C that does not overlap with the light-emitting region 41a. Figure 15 As shown in (c), in this embodiment, the reflected light Lcr is incident on a region of the laser source 41B that does not overlap with the light-emitting region 41a. Figure 15 As shown in (d), in this embodiment, the backlight Ldr is incident on the region of the laser source 41A that does not overlap with the light-emitting region 41a.

[0100] As described above, in the laser device 1, when viewed from the X-axis direction, the position of at least one laser (e.g., laser La) among the lasers La, Lb, Lc, and Ld emitted from the laser module 2 in the Z-axis direction, positioned relative to the second reference line 3c on one side of the Z-axis, is asymmetrical with respect to the second reference line 3c compared to the positions of all lasers Lc and Ld positioned relative to the other side of the Z-axis. Therefore, even if laser La is reflected as a return light Lar after being reflected from the incident end face 46a of the optical fiber 46 and incident on the laser source 41D, the position of the return light Lar is not consistent with the position of the emitting region 41a of the laser source 41D, thus suppressing the degradation of the laser source 41D. Furthermore, the focal distance Fd of the fast-axis collimating lens 42A is greater than the minimum value among the intervals G1, G2, and G3 between the lasers La, Lb, Lc, and Ld emitted from the laser module 2 in the Z-axis direction arrangement. This increases the distance between the laser source 41A and the incident surface 421 of the fast-axis collimating lens 42A, making it easier to mount the fast-axis collimating lens 42A relative to the laser source 41A. Therefore, manufacturing the laser device 1 becomes easier. Consequently, according to the laser device 1, laser source degradation caused by backlighting can be suppressed, and manufacturing becomes easier.

[0101] If the focal distance Fd of the fast-axis collimating lens 42A is reduced and the spot diameter of the laser La is decreased, it is easier to change the configuration of the laser La incident on the restricted area (e.g., the condenser lens 3). However, the smaller the focal distance Fd of the fast-axis collimating lens 42A, the more precise the assembly of the fast-axis collimating lens 42A relative to the laser source 41A becomes required. In this embodiment, by making the focal distance Fd of the fast-axis collimating lens 42A greater than the minimum value among the intervals G1, G2, and G3, the assembly of the fast-axis collimating lens 42A relative to the laser source 41A becomes easier, while the lasers La, Lb, Lc, and Ld are configured in a non-uniform manner with intervals G1, G2, and G3, thus suppressing the degradation of the laser source caused by backlighting.

[0102] When viewed from the X-axis direction, among the multiple lasers La, Lb, Lc, and Ld emitted from laser module 2 arranged along the Z-axis direction, the positions of all lasers La and Lb on one side of the Z-axis relative to the second reference line 3c are asymmetrical with respect to the second reference line 3c compared to the positions of all lasers Lc and Ld on the other side of the Z-axis relative to the second reference line 3c. This reliably suppresses laser source degradation caused by backlighting.

[0103] Laser module 2 has a support body 30 comprising mounting surfaces 33a, 33b, 33c, and 33d arranged in a stepped manner, with their positions in the Z-axis direction increasing the further away from the condenser lens 3 in the X-axis direction. Laser light sources 41A, 41B, 41C, and 41D are disposed on mounting surfaces 33a, 33b, 33c, and 33d and emit lasers La, Lb, Lc, and Ld towards one side in the Y-axis direction. Laser units 40A, 40B, 40C, and 40D include reflectors 50A, 50B, 50C, and 50D disposed downstream of the slow-axis collimating lenses 44A, 44B, 44C, and 44D in the optical path and reflecting the lasers La, Lb, Lc, and Ld emitted from the slow-axis collimating lenses 44A, 44B, 44C, and 44D towards the condenser lens 3 in the X-axis direction. Reflectors 50A, 50B, 50C, and 50D are arranged along the X-axis when viewed from the Z-axis direction. Reflectors 50A, 50B, 50C, and 50D include a reflecting surface 51 that overlaps with laser sources 41A, 41B, 41C, and 41D when viewed from the Y-axis direction. Therefore, by adjusting the positions of the mounting surfaces 33a, 33b, 33c, and 33d in the Z-axis direction, the asymmetric state of the position of at least one laser (e.g., laser La) located on one side of the second reference line 3c in the Z-axis direction and the positions of all lasers Lc and Ld located on the other side of the second reference line 3c in the Z-axis direction can be adjusted.

[0104] The laser device 1 includes a wavelength filter 5. The wavelength filter 5 is disposed between the laser module 2 (multiple laser units 40A, 40B, 40C, 40D) and the optical fiber 46. The wavelength filter 5 allows the laser light La, Lb, Lc, and Ld emitted from the laser module 2 to pass through and reflects the light emitted from the optical fiber 46. This suppresses light incident from outside the housing 6 into the housing 6 via the optical fiber 46, preventing it from entering the housing 6 and impacting the laser units 40A, 40B, 40C, and 40D.

[0105] The focal distance Fd of the fast-axis collimating lens 42A is 100μm to 400μm. Therefore, as described above, mounting the fast-axis collimating lens 42A relative to the laser source 41A becomes easier, thus simplifying the manufacture of the laser device 1. Furthermore, the positioning of the fast-axis collimating lens 42A relative to the laser source 41A can be easily performed while reducing the width of the laser beam La.

[0106] The spacings G1, G2, and G3 are 100 μm to 500 μm. Therefore, as described above, the mounting of the fast-axis collimating lens 42A relative to the laser source 41A becomes easier, thus simplifying the manufacture of the laser device 1. Furthermore, it is possible to suppress the obstruction of laser lasing elements La, Lb, Lc, and Ld caused by the reflectors 50A, 50B, 50C, and 50D, and to allow the laser lasing elements La, Lb, Lc, and Ld to be incident within the numerical aperture (NA) of the fiber 46.

[0107] The difference between the intervals G1, G2, and G3 is less than 700 μm. This allows for the realization of the asymmetric state described above. Furthermore, it enables the appropriate incidence of laser beams La, Lb, Lc, and Ld within the numerical aperture of the fiber 46.

[0108] When viewed from the X-axis direction, the distance (first distance R1) from the nth laser (e.g., laser La) located on one side of the second reference line 3c relative to the second reference line 3c in the Z-axis direction, relative to the second reference line 3c, to the second reference line 3c, is different from the distance (fourth distance R4) from the nth laser (e.g., laser Ld) located on the other side of the second reference line 3c relative to the second reference line 3c in the Z-axis direction, relative to the second reference line 3c, to the second reference line 3c, is 10μm to 500μm. Therefore, the luminous region 41a of the laser source 41D, which receives laser La as backlight Lar after reflection from the incident end face 46a of the optical fiber 46, and is incident on the output laser Ld, can be suppressed. Similarly, the luminous region 41a of the laser source 41A, which receives laser Ld as backlight Ldr after reflection from the incident end face 46a of the optical fiber 46, can be suppressed. Therefore, it is possible to suppress the degradation of the laser source caused by backlighting. In addition, it is possible to appropriately direct the laser spectroscopy (La, Lb, Lc, Ld) into the numerical aperture of the fiber 46.

[0109] The same function and effect of laser unit 40A can be achieved in laser units 40B, 40C, and 40D.

[0110] [Second Implementation]

[0111] The laser device of the second embodiment differs from the laser device of the first embodiment in that it emits multiple laser beams from a single laser source. For example... Figure 16 As shown, each laser source 41A, 41B, 41C, and 41D can replace the semiconductor laser element 412 and include, for example, a laser diode bar 413. The laser diode bar 413 includes multiple light-emitting regions 41a. For example, the laser diode bar 413 includes two light-emitting regions 41a. The multiple light-emitting regions 41a are arranged along the X-axis direction. The distance between adjacent light-emitting regions 41a (center-to-center distance) is, for example, 150 μm to 300 μm. Each light-emitting region 41a emits a laser beam La. Each laser beam La uses the Z-axis direction as its fast axis and the X-axis direction as its slow axis.

[0112] like Figure 17 As shown, when multiple laser beams La are emitted from the laser diode strip 413, the laser unit 40A further includes a prism unit 43A. The prism unit 43A is disposed in the optical path between the fast-axis collimating lens 42A and the slow-axis collimating lens 44A. The prism unit 43A is disposed on the base surface 33e of the support 30. The prism unit 43A is fixed to the base surface 33e, for example, by means of a UV-curable resin. The prism unit 43A may also be fixed to the fast-axis collimating lens 42A, for example, by means of a UV-curable resin.

[0113] Prism unit 43A adjusts the arrangement direction of multiple lasers La so that the multiple lasers La emitted from fast-axis collimating lens 42A in a state arranged along the X-axis direction are incident on slow-axis collimating lens 44A in a state arranged along the Z-axis direction. Prism unit 43A is composed of multiple prisms.

[0114] like Figure 18As shown, multiple lasers La emitted from laser source 41A, arranged along the X-axis, are emitted from slow-axis collimating lens 44A, arranged along the Z-axis, and then reflected by mirror 50A. Laser source 41B, similar to laser source 41A, emits multiple lasers Lb arranged along the X-axis. These multiple lasers Lb, like the multiple lasers La, are emitted from slow-axis collimating lens 44B, arranged along the Z-axis, and then reflected by mirror 50B. Laser source 41C, similar to laser source 41A, emits multiple lasers Lc arranged along the X-axis. These multiple lasers Lc, like the multiple lasers La, are emitted from slow-axis collimating lens 44C, arranged along the Z-axis, and then reflected by mirror 50C. Laser source 41D, similar to laser source 41A, emits multiple lasers Ld arranged along the X-axis. Like multiple lasers La, multiple lasers Ld, arranged along the Z-axis, exit from the slow-axis collimating lens 44D and are reflected by the reflecting mirror 50D. Multiple lasers La, Lb, Lc, and Ld, arranged along the Z-axis, are incident on the condenser lens 3 and focused into a single laser L. With this structure, the light output of laser sources 41A, 41B, 41C, and 41D can be maintained while suppressing the degradation of these sources as described above.

[0115] [Variation Example]

[0116] This disclosure is not limited to the embodiments described above.

[0117] like Figure 19 As shown, each laser source 41A, 41B, 41C, and 41D can replace one semiconductor laser element 412, and instead include multiple semiconductor laser elements 414. Each semiconductor laser element 414 can include a light-emitting region 41a. In this case, similar to the second embodiment, each laser unit 40A, 40B, 40C, and 40D can further have a prism unit. According to this structure, it is possible to suppress the degradation of laser sources 41A, 41B, 41C, and 41D as described above while maintaining the light output of the laser sources 41A, 41B, 41C, and 41D.

[0118] In this embodiment, when viewed from the X-axis direction, the positions of all lasers La and Lb on one side of the second reference line 3c in the Z-axis direction are asymmetrical with respect to the second reference line 3c compared to the positions of all lasers Lc and Ld on the other side of the second reference line 3c in the Z-axis direction. However, for example, the positions of lasers La and Lc or Ld can be symmetrical to each other. When viewed from the X-axis direction, it is sufficient that the position of at least one laser on one side of the second reference line 3c in the Z-axis direction is asymmetrical with respect to the second reference line 3c compared to the positions of all lasers on the other side of the second reference line 3c in the Z-axis direction.

[0119] In one embodiment, the laser light source 41A has a sub-base 411, but the laser light source 41A may also not have a sub-base 411. In this case, the semiconductor laser element 412 of the laser light source 41A can be fixed to the support 30, for example, by solder material.

[0120] In one embodiment, reflectors 50A, 50B, 50C, and 50D are fixed to the support 30, but reflectors 50A, 50B, 50C, and 50D may also be fixed to the housing 6, for example.

[0121] In this embodiment, the laser device 1 is used for the excitation of a fiber laser, but the laser device 1 can also be used for laser processing, for example.

[0122] In this embodiment, when viewed from the X-axis direction, the position of at least one laser on one side of the second reference line 3c in the Z-axis direction is asymmetrical with respect to the second reference line 3c compared to the positions of all lasers on the other side of the second reference line 3c in the Z-axis direction. However, the lasers La, Lb, Lc, and Ld emitted from the laser module 2 in the Z-axis direction arrangement can be symmetrical with respect to the second reference line 3c when viewed from the X-axis direction. This is only necessary if the focal distance Fd of the fast-axis collimating lens 42A is greater than the minimum of the intervals G1, G2, and G3 between the lasers La, Lb, Lc, and Ld emitted from the laser module 2 in the Z-axis direction arrangement. In this case, the incident end face 46a of the optical fiber 46 may not be perpendicular to the optical axis 3a of the condenser lens 3. Even in this case, as described above, the installation of the fast-axis collimating lens 42A relative to the laser source 41A becomes easier. Therefore, the manufacture of the laser device 1 becomes easier.

[0123] In one embodiment, the condenser lens 3 is separate from the laser module 2, but the condenser lens 3 can also be fixed to the support 30 while being disposed on the main surface 32 of the support 30 of the laser module 2. In another embodiment, the wavelength filter 5 is separate from the laser module 2, but the wavelength filter 5 can also be fixed to the support 30 while being disposed on the main surface 32 of the support 30 of the laser module 2.

[0124] Explanation of reference numerals in the attached figures

[0125] 1…Laser device, 2…Laser module, 3…Condenser lens, 3a…Optical axis, 3c…Second reference line, 5…Wavelength filter, 6…Housing, 30…Support body, 33a…First mounting surface, 33b…Second mounting surface, 33c…Third mounting surface, 33d…Fourth mounting surface, 40A, 40B, 40C, 40D…Laser units, 41A, 41B, 41C, 41D…Laser source, 41a…Emitting area, 42A, 42B, 42C, 42D…Fast-axis collimating lens, 44A, 44B, 44C, 44D…Slow-axis collimating lens, 46…Fiber optic cable, 46a…Incident end face, 50A, 50B, 50C, 50D…Reflector, 51…Reflecting surface, Fd…Focus distance, G1…First interval, G2…Second interval, G3…Third interval, La, Lb, Lc, Ld…Laser.

Claims

1. A laser device, characterized in that, have: A laser module that emits multiple lasers arranged along a first direction toward a second direction that intersects the first direction; A focusing lens having an optical axis parallel to the second direction and focusing the plurality of laser beams; An optical fiber having an incident end face perpendicular to the optical axis of the condenser lens, and propagating the plurality of laser beams focused by the condenser lens; and The housing contains the laser module and the focusing lens. The laser module has multiple laser units. The plurality of laser units each comprise: A laser source that emits at least one of the plurality of lasers; A fast-axis collimating lens is disposed in the optical path of the laser to collimate the laser emitted from the laser source in the fast-axis direction along the first direction; and A slow-axis collimating lens is disposed downstream of the fast-axis collimating lens in the optical path, and collimates the laser light emitted from the fast-axis collimating lens in the slow-axis direction. When viewed from the second direction, the multiple intervals between the plurality of lasers emitted from the laser module in the state of being arranged along the first direction are not uniform. When viewed from the second direction, the positions of at least one laser among the plurality of lasers emitted from the laser module, arranged along the first direction, located on one side of the reference line in the first direction, and the positions of all lasers located on the other side of the reference line in the first direction, are asymmetrical about the reference line, which extends along a third direction intersecting both the first and second directions and passes through the optical axis of the condenser lens. The focal distance of the fast-axis collimating lens of each of the plurality of laser units is greater than the minimum value among the plurality of intervals.

2. The laser device according to claim 1, characterized in that, When viewed from the second direction, the positions of all lasers emitted from the laser module in the state of being arranged along the first direction, which are located on one side of the reference line in the first direction, are asymmetrical with respect to the reference line with respect to the other side of the reference line in the first direction.

3. The laser device according to claim 1 or 2, characterized in that, The laser module further comprises a support body including multiple mounting surfaces, the multiple mounting surfaces being arranged in a stepped manner such that the position in the first direction is higher the further away from the condenser lens in the second direction. The laser light source of each of the plurality of laser units is disposed on each of the plurality of mounting surfaces and emits the laser towards the third direction. Each of the plurality of laser units further includes a reflector disposed downstream of the optical path relative to the slow-axis collimating lens, and reflecting the laser emitted from the slow-axis collimating lens toward the condenser lens along the second direction. The reflectors of each of the plurality of laser units are arranged along the second direction when viewed from the first direction, and include a reflective surface that overlaps with the laser source when viewed from the third direction.

4. The laser device according to any one of claims 1 to 3, characterized in that, It also includes a wavelength filter, which is disposed between the plurality of laser units and the optical fiber, so that the plurality of lasers emitted from the plurality of laser units can pass through and reflect the light emitted from the optical fiber.

5. The laser device according to any one of claims 1 to 4, characterized in that, The focal distance of the fast-axis collimating lens is 100μm~400μm.

6. The laser device according to any one of claims 1 to 5, characterized in that, The multiple intervals are 100μm to 500μm respectively.

7. The laser device according to any one of claims 1 to 5, characterized in that, The difference between each of the plurality of intervals is less than 700 μm.

8. The laser device according to any one of claims 1 to 7, characterized in that, When viewed from the second direction, the distance from the nth laser relative to the reference line on one side of the first direction to the reference line is 10 μm to 500 μm, and the distance from the nth laser relative to the reference line on the other side of the first direction to the reference line is 10 μm to 500 μm, where n is a natural number.

9. The laser device according to any one of claims 1 to 8, characterized in that, Each of the plurality of laser units has a laser diode strip as its laser source. The laser diode strip contains multiple light-emitting areas.

10. The laser device according to any one of claims 1 to 8, characterized in that, Each of the plurality of laser units has a laser source having a plurality of semiconductor laser elements. Each of the plurality of semiconductor laser elements includes a light-emitting region.

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