Laser module and laser processing machine

Abstract

To provide a laser module capable of easily adjusting the positions of first and second lasers.SOLUTION: First and second lasers provided on a first plane and configured to respectively emit first and second light beams in a first direction, a first mirror configured to reflect the first light beam, a second mirror configured to transmit the first light beam in a second direction and reflect the second light beam in the second direction, and first and second condensing optical systems respectively provided between the first and second lasers and the first and second mirrors, A distance between the first laser light source and a principal point of the first condensing optical system is larger than a distance between the second laser light source and a principal point of the second condensing optical system, an optical path length from the first laser to the second mirror is larger than an optical path length from the second laser to the second mirror, and a focal length of the first condensing optical system is larger than a focal length of the second condensing optical system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laser module and a laser processing machine. [Background technology]

[0002] In order to achieve high output, a laser module is known that combines and emits light from a plurality of laser light sources.

[0003] For example, Patent Document 1 describes a light beam exposure device that includes a plurality of light source units having different wavelength characteristics, a dichroic mirror that combines the light beams with different wavelength characteristics emitted from the plurality of light source units, and an imaging optical system that irradiates the light beams from the dichroic mirror onto an exposure surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-141757 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the light beam exposure device described in Patent Document 1, since the plurality of light source units are arranged in a stepped manner, it is difficult to adjust the positions of the plurality of light source units. [Means for solving the problem]

[0006] One aspect of the laser module according to the present invention is a first substrate; a first laser light source provided on a first plane of the first substrate and configured to emit first light in a first direction that is a direction perpendicular to the first plane; a second laser light source provided on the first plane and configured to emit second light in the first direction; a first mirror that reflects the first light emitted in the first direction from the first laser light source; a second mirror that transmits the first light reflected by the first mirror in a second direction different from the first direction and reflects the second light emitted from the second laser light source in the second direction; a first focusing optical system provided between the first laser light source and the first mirror; a second focusing optical system provided between the second laser light source and the second mirror; Including, a radiation angle of the first light emitted from the first laser light source and a radiation angle of the second light emitted from the second laser light source are the same; an optical path length from the first laser light source to a principal point of the first focusing optical system is longer than an optical path length from the second laser light source to a principal point of the second focusing optical system; an optical path length from the first laser light source to the second mirror is longer than an optical path length from the second laser light source to the second mirror; The focal length of the first focusing optical system is greater than the focal length of the second focusing optical system.

[0007] One aspect of the laser processing machine according to the present invention is: The laser module is included. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically showing a laser module according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram schematically showing a laser module according to an embodiment of the present invention. [Figure 3] FIG. 2 is a cross-sectional view schematically showing a first laser light source of the laser module according to the embodiment. [Figure 4] FIG. 10 is a diagram schematically showing a laser module according to a first modified example of the embodiment. [Figure 5] FIG. 10 is a diagram schematically showing a laser module according to a first modified example of the embodiment. [Figure 6]FIG. 10 is a diagram schematically showing a laser module according to a first modified example of the embodiment. [Figure 7] FIG. 10 is a perspective view schematically showing a laser module according to a second modified example of the embodiment. [Figure 8] FIG. 10 is a diagram schematically showing a laser module according to a third modified example of the embodiment. [Figure 9] FIG. 10 is a diagram schematically showing a laser module according to a third modified example of the embodiment. [Figure 10] FIG. 10 is a diagram schematically showing a laser module according to a fourth modified example of the embodiment. [Figure 11] FIG. 10 is a diagram schematically showing a laser module according to a fourth modified example of the embodiment. [Figure 12] FIG. 1 is a diagram schematically showing a laser processing machine according to an embodiment of the present invention. [Figure 13] FIG. 10 is a diagram for explaining a simulation. [Figure 14] Table to explain the simulation. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0010] 1. Laser module 1.1. Overall structure First, the laser module according to this embodiment will be described with reference to the drawings. Fig. 1 is a diagram schematically showing a laser module 100 according to this embodiment. Note that Fig. 1 illustrates an X-axis, a Y-axis, and a Z-axis as three mutually orthogonal axes.

[0011] 1, the laser module 100 includes, for example, a first substrate 11, a first laser light source 21, a second laser light source 22, a first mirror 31, a second mirror 32, a first focusing optical system 41, a second focusing optical system 42, and a housing 50. For convenience, the housing 50 is shown in a see-through manner in FIG.

[0012] The first substrate 11 supports the first laser light source 21 and the second laser light source 22. The first substrate 11 has a first plane 11a. The first plane 11a is a flat surface. In the illustrated example, a perpendicular line N to the first plane 11a is parallel to the Z axis. The first substrate 11 is, for example, a copper substrate or a silicon substrate. The first substrate 11 dissipates heat generated by the laser light sources 21 and 22.

[0013] The first laser light source 21 is provided on the first plane 11a of the first substrate 11. The first laser light source 21 is provided, for example, directly on the first plane 11a. The first laser light source 21 has an emission surface 21a from which light is emitted. In the example shown in the figure, the emission surface 21a is parallel to the first plane 11a. The emission surface 21a is the surface of the first laser light source 21 opposite to the first substrate 11.

[0014] The first laser light source 21 emits the first light L1 in a first direction D1, which is the direction of the perpendicular line N. In the illustrated example, the first direction D1 is the +Z-axis direction. Here, "emitting light in the A direction" means emitting light so that the optical axis of the light is in the A direction. Similarly, "transmitting light in the A direction" and "reflecting light in the A direction" mean transmitting and reflecting light so that the optical axis of the light is in the A direction, respectively. The "optical axis of light" refers to the ray of the light beam that passes through the center of the focusing optical system.

[0015] The second laser light source 22 is provided on the first plane 11a of the first substrate 11. The second laser light source 22 is provided, for example, directly on the first plane 11a. In the illustrated example, the laser light sources 21 and 22 are aligned in the Y-axis direction. The emission surface 21a of the first laser light source 21 and the emission surface 22a of the second laser light source 22 are located on the same plane. The second laser light source 22 emits second light L2 in a first direction D1.

[0016] The radiation angle θ1 of the first light L1 emitted from the first laser light source 21 and the radiation angle θ2 of the second light L2 emitted from the second laser light source 22 are the same. The laser light sources 21 and 22 are, for example, semiconductor lasers. Specifically, the laser light sources 21 and 22 are photonic crystal surface emitting lasers (PCSELs). Note that the laser light sources 21 and 22 may be lasers other than semiconductor lasers.

[0017] The first mirror 31 reflects the first light L1 emitted from the first laser light source 21 in the first direction D1 in the second direction D2. The second direction D2 is a direction different from the first direction D1. The first direction D1 and the second direction D2 are directions perpendicular to each other. In the illustrated example, the second direction D2 is the -Y-axis direction. The first mirror 31 bends the first light L1 by 90 degrees. Specifically, the first mirror 31 reflects the first light L1 collected by the first collecting optical system 41.

[0018] The second mirror 32 transmits the first light L1 reflected by the first mirror 31 in the second direction D2, and reflects the second light L2 emitted from the second laser light source 22 in the first direction D1 in the second direction D2. The second mirror 32 then combines the first light L1 and the second light L2. The second mirror 32 bends the second light L2 by 90 degrees. Specifically, the second mirror 32 reflects the second light L2 collected by the second collecting optical system 42. The optical path length from the first laser light source 21 to the second mirror 32 is longer than the optical path length from the second laser light source 22 to the second mirror 32.

[0019] The second mirror 32 is, for example, a polarization beam combiner (PBC). For example, the laser light sources 21 and 22, which are PCSELs, can adjust the polarization directions of the light L1 and L2, respectively, by composite modulation. The light L1 and L2 have different polarization directions. For example, the first light L1 is P-polarized light, and the second light L2 is S-polarized light. In the illustrated example, the mirrors 31 and 32 are aligned in the Y-axis direction. The light L1 and L2 are incident on the second mirror 32 as light with different polarization directions. The light L1 and L2 have the same polarization direction when emitted from the laser light sources 21 and 22, respectively, but may have different polarization directions when incident on the second mirror 32.

[0020] The first light L1 emitted from the first laser light source 21 and the second light L2 emitted from the second laser light source 22 may have the same polarization direction. The light L1 and L2 may be, for example, P-polarized light. In this case, as shown in FIG. 2, a λ / 2 plate 30 is provided between the second laser light source 22 and the second focusing optical system 42. The λ / 2 plate 30 converts the P-polarized second light L2 emitted from the second laser light source 22 into S-polarized light. This allows the second mirror 32 to combine the first light L1 emitted from the first laser light source 21 and the second light L2 emitted from the second laser light source 22. If the polarization directions of the light L1 and L2 are the same, the laser light sources 21 and 22 can be configured exactly the same. This makes it possible to equalize the changes over time and manufacturing variations of the laser light sources 21 and 22.

[0021] However, if the laser light sources 21 and 22 are PCSELs, the polarization of the light L1 and L2 can be adjusted by composite modulation without using the λ / 2 plate 30, which reduces the number of parts and improves the size and This will enable cost reduction.

[0022] As shown in FIG. 1 , the first focusing optical system 41 is provided between the first laser light source 21 and the first mirror 31. The first focusing optical system 41 focuses the first light L1 emitted from the first laser light source 21 at a focusing point F. The second focusing optical system 42 is provided between the second laser light source 22 and the second mirror 32. The second focusing optical system 42 focuses the second light L2 emitted from the second laser light source 22 at a focusing point F. The focusing optical systems 41 and 42 are focusing lenses. In the example shown in the figure, the focusing optical systems 41 and 42 are convex lenses. The focusing point F is an image formation point of the focusing optical systems 41 and 42. At the focusing point F, the magnification of the light source image formed by the first light L1 and the light source image formed by the second light L2 are the same.

[0023] The distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41 is greater than the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. Specifically, the distance along the optical path between the first laser light source 21 and the principal point H1 of the first focusing optical system 41 is greater than the distance along the optical path between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. In the present invention, the term "principal point" simply refers to the front principal point when the light source side is defined as the object side. The front principal point is also called the object-side principal point.

[0024] The focal length of the first focusing optical system 41 is greater than the focal length of the second focusing optical system 42. In other words, the distance along the optical path between the rear principal point of the focusing optical system 41 and the focusing point F is greater than the distance along the optical path between the rear principal point of the focusing optical system 42 and the focusing point F. The rear principal point is also called the image side principal point.

[0025] The lens surface of the first focusing optical system 41 and the lens surface of the second focusing optical system 42 have, for example, different curvatures. The first focusing optical system 41 is located halfway along the optical path from the first laser light source 21 to the focusing point F. The second focusing optical system 42 is located halfway along the optical path from the second laser light source 22 to the focusing point F.

[0026] The housing 50 houses the first substrate 11, the laser light sources 21 and 22, the mirrors 31 and 32, and the focusing optical systems 41 and 42. The shape and material of the housing 50 are not particularly limited. Although not shown, the housing 50 has a window portion that transmits the light beams L1 and L2. The housing 50 makes it easy to handle the laser module 100.

[0027] 1.2. Laser light source configuration 3 is a cross-sectional view schematically showing the first laser light source 21. As shown in FIG. 3, the first laser light source 21 has, for example, a first semiconductor layer 61, a first guide layer 62, a quantum well layer 63, a second guide layer 64, a second semiconductor layer 65, a transparent substrate 66, a first electrode 67, and a second electrode 68. The first laser light source 21 and the second laser light source 22 basically have the same structure. Therefore, the following description of the first laser light source 21 can also be applied to the description of the second laser light source 22.

[0028] The first semiconductor layer 61 is provided between the first electrode 67 and the first guide layer 62. The first semiconductor layer 61 is a semiconductor layer of a first conductivity type. The first semiconductor layer 61 is, for example, a p-type semiconductor layer doped with Mg.

[0029] The first guide layer 62 is provided between the first semiconductor layer 61 and the quantum well layer 63. The first guide layer 62 has, for example, an SL (Semiconductor Superlattice) structure made up of an i-type GaN layer and an InGaN layer that are not intentionally doped with impurities. The number of GaN layers and InGaN layers that make up the first guide layer 62 is not particularly limited.

[0030] Apertures 69 are formed in the first guide layer 62. The apertures 69 are, for example, holes. The width of the apertures 69 is, for example, 50 nm or more and 500 nm or less. A plurality of apertures 69 are formed. The plurality of apertures 69 are periodically arranged when viewed from the Z-axis direction. The plurality of apertures 69 are arranged, for example, in the form of a regular triangular lattice or a square lattice. The plurality of apertures 69 can exhibit a photonic crystal effect.

[0031] The quantum well layer 63 is provided between the first guide layer 62 and the second guide layer 64. The quantum well layer 63 generates light when a current is injected into it. The quantum well layer 63 has, for example, a well layer and a barrier layer. The well layer and the barrier layer are i-type semiconductor layers that are not intentionally doped with impurities. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The quantum well layer 63 has an MQW (Multiple Quantum Well) structure composed of the well layer and the barrier layer.

[0032] There is no particular limitation on the number of well layers and barrier layers that make up the quantum well layer 63. For example, only one well layer may be provided, in which case the quantum well layer 63 has an SQW (Single Quantum Well) structure.

[0033] The second guide layer 64 is provided between the quantum well layer 63 and the second semiconductor layer 65. The second guide layer 64 has an SL structure composed of, for example, an i-type GaN layer that is not intentionally doped with impurities and an InGaN layer. The number of GaN layers and InGaN layers that make up the second guide layer 64 is not particularly limited. The first guide layer 62 and the second guide layer 64 have the function of increasing the optical confinement coefficient of the first laser light source 21. Although not shown, the multiple openings 69 may be formed in the second guide layer 64 instead of in the first guide layer 62.

[0034] The second semiconductor layer 65 is provided between the quantum well layer 63 and a transparent substrate 66. The second semiconductor layer 65 is a semiconductor layer of a second conductivity type different from the first conductivity type. The second semiconductor layer 65 is, for example, an n-type GaN layer doped with Si. The first semiconductor layer 61 and the second semiconductor layer 65 are cladding layers that have the function of confining light in the quantum well layer 63.

[0035] In the first laser light source 21, a p-type first semiconductor layer 61, an i-type quantum well layer 63 and guide layers 62 and 64 that are not intentionally doped with impurities, and an n-type second semiconductor layer 65 form a p-i-n diode. In the first laser light source 21, when a forward bias voltage of the p-i-n diode is applied between the first electrode 67 and the second electrode 68, a current is injected into the quantum well layer 63, causing recombination of electrons and holes in the quantum well layer 63. This recombination generates light. The light generated in the quantum well layer 63 propagates in the in-plane direction and forms a standing wave due to the photonic crystal effect of the multiple openings 69. The light then receives gain in the quantum well layer 63 and oscillates as a laser. The first laser light source 21 then emits the diffracted light as laser light.

[0036] The transparent substrate 66 is provided between the second semiconductor layer 65 and the second electrode 68. The transparent substrate 66 transmits light generated in the quantum well layer 63. The transparent substrate 66 is, for example, an n-type semiconductor substrate doped with Si.

[0037] The first electrode 67 is provided on the opposite side of the first semiconductor layer 61 to the first guide layer 62. The first semiconductor layer 61 may be in ohmic contact with the first electrode 67. The first electrode 67 is electrically connected to the first semiconductor layer 61. The first electrode 67 is formed by laminating, for example, a Ni layer and an Au layer in this order from the first semiconductor layer 61 side. The first electrode 67 is one of the electrodes for injecting a current into the quantum well layer 63.

[0038] The second electrode 68 is provided on the transparent substrate 66 on the opposite side to the second semiconductor layer 65. The transparent substrate 66 may be in ohmic contact with the second electrode 68. The second electrode 68 is electrically connected to the second semiconductor layer 65 via the transparent substrate 66. The second electrode 68 is formed by laminating, for example, a Cr layer, a Ni layer, and an Au layer in this order from the transparent substrate 66 side. The second electrode 68 is the other electrode for injecting current into the quantum well layer 63.

[0039] A through-hole 68a is formed in the second electrode 68. Light generated in the quantum well layer 63 is emitted through the through-hole 68a. The area of ​​the transparent substrate 66 exposed by the through-hole 68a forms the emission surface 21a.

[0040] In a method for manufacturing the first laser light source 21, the semiconductor layers 61 and 65, the guide layers 62 and 64, and the quantum well layer 63 are formed by epitaxial growth, for example, by MOCVD (Metal Organic Chemical Vapor Deposition) or MBE (Molecular Beam Epitaxy). The opening 69 is formed, for example, by patterning the first guide layer 62 using an electron beam lithography system. The electrodes 67 and 68 are formed by sputtering, vacuum deposition, CVD (Chemical Vapor Deposition), or the like. The formed first laser light source 21 is mounted junction-down, for example, with the first electrode 67 facing the first substrate 11 shown in FIG. 1.

[0041] 1.3. Effects The laser module 100 includes a first substrate 11, a first laser light source 21 provided on a first plane 11a of the first substrate 11 and emitting a first light L1 in a first direction D1 that is a direction of a normal N to the first plane 11a, a second laser light source 22 provided on the first plane 11a and emitting a second light L2 in the first direction D1, a first mirror 31 that reflects the first light L1 emitted from the first laser light source 21 in the first direction D1, a second mirror 32 that transmits the first light L1 reflected by the first mirror 31 in a second direction D2 different from the first direction D1 and reflects the second light L2 emitted from the second laser light source 22 in the second direction D2, a first focusing optical system 41 provided between the first laser light source 21 and the first mirror 31, and a second focusing optical system 42 provided between the second laser light source 22 and the second mirror 32. The radiation angle θ1 of the first light L1 emitted from the first laser light source 21 is the same as the radiation angle θ2 of the second light L2 emitted from the second laser light source 22. The distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41 is longer than the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. The optical path length from the first laser light source 21 to the second mirror 32 is longer than the optical path length from the second laser light source 22 to the second mirror 32. The focal length of the first focusing optical system 41 is longer than the focal length of the second focusing optical system 42.

[0042] Therefore, in the laser module 100, the positions of the first laser light source 21 and the second laser light source 22 can be adjusted by adjusting the position of the first substrate 11. Therefore, the positions of the laser light sources 21, 22 can be easily adjusted. Furthermore, the laser light sources 21, 22 can be easily mounted. Furthermore, since heat generated by the laser light sources 21, 22 can be dissipated by the single first substrate 11, the temperature characteristics of the laser light sources 21, 22 can be made uniform. This improves reliability and stability. Furthermore, temperature control of the laser light sources 21, 22 can be easily performed. Furthermore, high output can be maintained by adjusting the focusing optical systems 41, 42 in response to changes over time in the laser light sources 21, 22.

[0043] Furthermore, in the laser module 100, the radiation angle θ1 of the first light L1 and the radiation angle θ2 of the second light L2 are the same, the distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41 is longer than the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42, the optical path length from the first laser light source 21 to the second mirror 32 is longer than the optical path length from the second laser light source 22 to the second mirror 32, and the focal length of the first focusing optical system 41 is Since the focal length of the light beam L1 is longer than that of the focusing optical system 42, the focusing position and the focusing angle of the light beams L1 and L2 can be aligned at the focusing point F. This allows for high output and high beam parameter (BPP) performance. It is possible to provide a high-quality laser module 100.

[0044] Furthermore, in the laser module 100, the spread of light can be suppressed compared to when a focusing optical system is provided after the second mirror, for example, which allows for miniaturization and cost reduction.

[0045] In the laser module 100, the first light L1 and the second light L2 are incident on the second mirror 32 as light beams having different polarization directions, and the second mirror 32 is a polarization beam combiner. Therefore, in the laser module 100, the first light L1 and the second light L2 can be combined at the second mirror 32.

[0046] In the laser module 100, the first laser light source 21 and the second laser light source 22 are photonic crystal surface-emitting lasers. Therefore, in the laser module 100, for example, the polarization directions of the first light L1 and the second light L2 can be adjusted by composite modulation.

[0047] Although the above description has been given of the case where the second mirror 32 is a polarization beam combiner, the second mirror 32 may be a dichroic mirror. In this case, the first light L1 emitted from the first laser light source 21 and the second light L2 emitted from the second laser light source 22 have different wavelengths. Therefore, the second mirror 32, which is a dichroic mirror, can transmit the first light L1 and reflect the second light L2. For example, the wavelengths of the lights L1 and L2 can be adjusted by combined modulation of the laser light sources 21 and 22, which are PCSELs. Using a PCSEL allows the wavelength of the emitted light to be precisely adjusted. For example, the second mirror 32 transmits light having a wavelength equal to or shorter than a predetermined wavelength and reflects light having a wavelength longer than the predetermined wavelength. The first light L1 and the second light L2 may have the same polarization direction.

[0048] Although not shown, a plurality of first focusing optical systems 41 may be provided between the first laser light source 21 and the first mirror 31. In this case, the principal point of the first focusing optical system 41 is the principal point when the plurality of first focusing optical systems 41 are virtually considered as one first focusing optical system 41. This also applies to the second focusing optical system 42.

[0049] Although not shown, a condenser lens may be provided on the optical path from the second mirror 32 to the condensing point F.

[0050] 2. Variations 2.1. First variant Next, a laser module according to a first modified example of this embodiment will be described with reference to the drawings. Fig. 4 is a diagram schematically showing a laser module 200 according to a first modified example of this embodiment.

[0051] Hereinafter, in the laser module 200 according to the first modified example of this embodiment, components having the same functions as the components of the laser module 100 according to this embodiment described above will be given the same symbols, and detailed descriptions thereof will be omitted.

[0052] 4, the laser module 200 differs from the laser module 100 described above in that it includes a second substrate 12, a third laser light source 23, a fourth laser light source 24, a third mirror 33, a fourth mirror 34, a fifth mirror 35, mirrors 36, 37, and 38, a third focusing optical system 43, and a fourth focusing optical system 44. The second substrate 12, the laser light sources 23 and 24, the mirrors 33, 34, 35, 36, 37, and 38, and the focusing optical system 43, 44 is housed in a housing 50.

[0053] The second substrate 12 is disposed opposite the first substrate 11. The second substrate 12 supports the third laser light source 23 and the fourth laser light source 24. The second substrate 12 has a second plane 12a. The second plane 12a of the second substrate 12 faces the first plane 11a of the first substrate 11. The second plane 12a is a flat surface. The first plane 11a and the second plane 12a are, for example, parallel to each other. The material of the second substrate 12 is, for example, the same as the material of the first substrate 11. The second substrate 12 dissipates heat generated by the laser light sources 23 and 24.

[0054] The third laser light source 23 is provided on the second plane 12a of the second substrate 12. The third laser light source 23 is provided, for example, directly on the second plane 12a. The third laser light source 23 is provided opposite the first laser light source 21. The third laser light source 23 has an emission surface 23a from which light is emitted. The emission surface 23a and the second plane 12a are, for example, parallel to each other. The emission surface 23a is the surface of the third laser light source 23 opposite to the second substrate 12.

[0055] The third laser light source 23 emits the third light L3 in a third direction D3. The third direction D3 is a direction along the perpendicular line N. The third direction D3 is a direction opposite to the first direction D1. In the illustrated example, the third direction D3 is the −Z-axis direction.

[0056] The fourth laser light source 24 is provided on the second plane 12a of the second substrate 12. The fourth laser light source 24 is provided, for example, directly on the second plane 12a. The fourth laser light source 24 is provided opposite the second laser light source 22. In the illustrated example, the laser light sources 23, 24 are aligned in the Y-axis direction. The emission surface 23a of the third laser light source 23 and the emission surface 24a of the fourth laser light source 24 are located on the same plane. The fourth laser light source 24 emits fourth light L4 in the third direction D3.

[0057] The radiation angle θ3 of the third light L3 emitted from the third laser light source 23 and the radiation angle θ4 of the fourth light L4 emitted from the fourth laser light source 24 are the same. The radiation angles θ1, θ2, θ3, and θ4 are, for example, the same. The laser light sources 23 and 24 are, for example, semiconductor lasers. Specifically, the laser light sources 23 and 24 are PCSELs. Note that the laser light sources 23 and 24 may be lasers other than semiconductor lasers.

[0058] The third mirror 33 reflects the third light L3 emitted from the third laser light source 23 in the third direction D3, in the second direction D2.

[0059] The fourth mirror 34 transmits the third light L3 reflected by the third mirror 33 in the second direction D2, and reflects the fourth light L4 emitted from the fourth laser light source 24 in the third direction D3 in the second direction D2. The fourth mirror 34 then combines the third light L3 and the fourth light L4. The optical path length from the third laser light source 23 to the fourth mirror 34 is longer than the optical path length from the fourth laser light source 24 to the fourth mirror 34.

[0060] The fourth mirror 34 is, for example, a polarization beam combiner. For example, the laser light sources 23 and 24, which are PCSELs, can adjust the polarization directions of the light beams L3 and L4, respectively, by composite modulation. The light beams L3 and L4 have different polarization directions. For example, the third light beam L3 is P-polarized light, and the fourth light beam L4 is S-polarized light. In the illustrated example, the mirrors 33 and 34 are aligned in the Y-axis direction.

[0061] The mirror 36 reflects the light L1 and L2 from the second mirror 32 in the first direction D1. The mirror 37 reflects the light L3 and L4 from the fourth mirror 34 in the third direction D3. 38 reflects the light L3 and L4 from the mirror 37 in the second direction D2.

[0062] The fifth mirror 35 is a dichroic mirror. The first light L1 and the second light L2 are light of a first wavelength. The third light L3 and the fourth light L4 are light of a second wavelength different from the first wavelength. Therefore, the fifth mirror 35, which is a dichroic mirror, can reflect the light L1 and L2 and transmit the light L3 and L4. Specifically, the fifth mirror 35 reflects the light L1 and L2 from the second mirror 32 in the second direction D2 and transmits the light L3 and L4 from the fourth mirror 34 in the second direction D2. More specifically, the fifth mirror 35 reflects the light L1 and L2 reflected by the mirror 36 in the second direction D2 and transmits the light L3 and L4 reflected by the mirror 38 in the second direction D2. The fifth mirror 35 combines the light L1 and L2 with the light L3 and L4.

[0063] The third focusing optical system 43 is provided between the third laser light source 23 and the third mirror 33. The third focusing optical system 43 focuses the third light L3 emitted from the third laser light source 23 at a focusing point F. The fourth focusing optical system 44 is provided between the fourth laser light source 24 and the fourth mirror 34. The fourth focusing optical system 44 focuses the fourth light L4 emitted from the fourth laser light source 24 at a focusing point F. The focusing optical systems 43, 44 are focusing lenses. In the illustrated example, the focusing optical systems 43, 44 are convex lenses.

[0064] The distance between the third laser light source 23 and the principal point H3 of the third collecting optical system 43 is greater than the distance between the fourth laser light source 24 and the principal point H4 of the fourth collecting optical system 44. The distance between the first laser light source 21 and the principal point H1 of the first collecting optical system 41 is the same as the distance between the third laser light source 23 and the principal point H3 of the third collecting optical system 43, for example. The distance between the second laser light source 22 and the principal point H2 of the second collecting optical system 42 is the same as the distance between the fourth laser light source 24 and the principal point H4 of the fourth collecting optical system 44, for example.

[0065] The focal length of the third condensing optical system 43 is greater than the focal length of the fourth condensing optical system 44. The focal length of the first condensing optical system 41 and the focal length of the third condensing optical system 43 are, for example, the same. The focal length of the second condensing optical system 42 and the focal length of the fourth condensing optical system 44 are, for example, the same.

[0066] The lens surface of the third focusing optical system 43 and the lens surface of the fourth focusing optical system 44 have, for example, different curvatures. The third focusing optical system 43 is located halfway along the optical path from the third laser light source 23 to the focusing point F. The fourth focusing optical system 44 is located halfway along the optical path from the fourth laser light source 24 to the focusing point F. In the laser module 200, the light beams L1, L2, L3, and L4 emitted from the laser light sources 21, 22, 23, and 24 can be focused at the focusing point F by the focusing optical systems 41, 42, 43, and 44, respectively.

[0067] The laser module 200 includes a second substrate 12 provided opposite to the first substrate 11, a third laser light source 23 provided on a second plane 12a of the second substrate 12 and emitting a third light L3 in a third direction D3 opposite to the first direction D1, a fourth laser light source 24 provided on the second plane 12a and emitting a fourth light L4 in the third direction D3, and a fourth laser light source 24 reflecting the third light L3 emitted from the third laser light source 23 in the third direction D3. a third mirror 33 that reflects the third light L3 reflected by the third mirror 33 in the second direction D2, a fourth mirror 34 that transmits the third light L3 reflected by the third mirror 33 in the second direction D2 and reflects the fourth light L4 emitted from the fourth laser light source 24 in the second direction D2, and a fifth mirror 35 that reflects the first light L1 and the second light L2 from the second mirror 32 in the second direction D2 and transmits the third light L3 and the fourth light L4 from the fourth mirror 34 in the second direction D2.

[0068] Therefore, the first light L1, the second light L2, the third light L3, and the fourth light L4 can be multiplexed in the laser module 200. This makes it possible to achieve high output.

[0069] In the laser module 300, the first light L1 and the second light L2 are light of a first wavelength, the third light L3 and the fourth light L4 are light of a second wavelength different from the first wavelength, and the fifth mirror 35 is a dichroic mirror. Therefore, in the laser module 200, the fifth mirror 35 can multiplex the first light L1, the second light L2, the third light L3, and the fourth light L4.

[0070] The first light L1 emitted from the first laser light source 21, the second light L2 emitted from the second laser light source 22, the third light L3 emitted from the third laser light source 23, and the fourth light L4 emitted from the fourth laser light source 24 may have the same direction of polarization. The light L1, L2, L3, and L4 may be, for example, S-polarized light.

[0071] 5, a λ / 2 plate 30 is provided on the optical path from the first laser light source 21 to the first focusing optical system 41 and on the optical path from the third laser light source 23 to the third focusing optical system 43. The λ / 2 plate 30 converts the S-polarized first light L1 emitted from the first laser light source 21 and the S-polarized third light L3 emitted from the third laser light source 23 into P-polarized light. This allows the second mirror 32 to combine the first light L1 emitted from the first laser light source 21 and the second light L2 emitted from the second laser light source 22. Furthermore, the fourth mirror 34 can combine the third light L3 emitted from the third laser light source 23 and the fourth light L4 emitted from the fourth laser light source 24.

[0072] Furthermore, although the above describes the case where the second mirror 32 and the fourth mirror 34 are polarized beam combiners and the fifth mirror 35 is a dichroic mirror, the second mirror 32 and the fourth mirror 34 may be dichroic mirrors and the fifth mirror 35 may be a polarized beam combiner.

[0073] In this case, the first light L1 and the third light L3 are light of a first wavelength, and the second light L2 and the fourth light L4 are light of a second wavelength different from the first wavelength. The light L1 and L2 are incident on the fifth mirror 35 as light of a first polarization, and the light L3 and L4 are incident on the fifth mirror 35 as light of a second polarization different from the first polarization. The first polarization may be S-polarized light, and the second polarization may be P-polarized light. Note that the laser light sources 21, 22, 23, and 24 may emit light of different wavelengths.

[0074] However, laser light sources that emit light of the same wavelength have the same temperature characteristics. Therefore, it is easier to control the temperature when the laser light sources 21 and 22 provided on the first substrate 11 emit light of the same wavelength and the laser light sources 23 and 24 provided on the second substrate 12 emit light of the same wavelength. This allows for stability against the environment.

[0075] Furthermore, when the second mirror 32 and the fourth mirror 34 are dichroic mirrors and the fifth mirror 35 is a polarization beam combiner, the laser light sources 21, 22, 23, and 24 emit light of a first polarization, and as shown in FIG. 6, a λ / 2 plate 30 may be provided in the optical path from mirror 36 to mirror 37. This allows the light L3 and L4 emitted from the laser light sources 23 and 24 to be converted from the first polarization to the second polarization. By arranging the fifth mirror 35, which is a polarization beam combiner, after the mirrors 32 and 34, which are dichroic mirrors, the number of polarization beam combiners can be reduced, thereby reducing costs.

[0076] 2.2. Second Variant Next, a laser module according to a second modified example of this embodiment will be described with reference to the drawings. Fig. 7 is a diagram schematically showing a laser module 300 according to the second modified example of this embodiment.

[0077] Hereinafter, in the laser module 300 according to the second modified example of this embodiment, components having the same functions as the components of the laser module 100 according to this embodiment described above will be given the same symbols, and detailed descriptions thereof will be omitted.

[0078] 7, the laser module 300 differs from the above-described laser module 100 in that it includes substrates 13 and 14, laser light sources 71 and 72, mirrors 81, 82, 83, 84, 85, and 86, and focusing optical systems 91 and 92. For convenience, the spread of light emitted from the laser light sources 21, 22, 71, and 72 is not shown in FIG.

[0079] The substrates 13 and 14 are provided on the first substrate 11. The material of the substrates 13 and 14 may be the same as or different from the material of the first substrate 11. The shapes of the substrates 13 and 14 may be the same as or different from each other. Providing the substrates 13 and 14 on the first substrate 11 makes mounting and assembly easier. Furthermore, the substrates 13 and 14 do not necessarily have to be provided together on the first substrate 11.

[0080] The laser light sources 21 and 71 are provided on the substrate 13. The laser light sources 21 and 71 are provided on the first substrate 11 with the substrate 13 interposed therebetween. The laser light sources 22 and 72 are provided on the substrate 14. The laser light sources 22 and 72 are provided on the first substrate 11 with the substrate 14 interposed therebetween. The laser light sources 71 and 72 emit light in a first direction D1. The optical axis of the light L1 emitted from the first laser light source 21, the optical axis of the light L2 emitted from the second laser light source 22, the optical axis of the light emitted from the laser light source 71, and the optical axis of the light emitted from the laser light source 72 are parallel to one another.

[0081] The laser light sources 21 and 71 emit light of the same wavelength. The laser light sources 22 and 72 emit light of the same wavelength. In the laser module 300, the laser light sources 21 and 71, which emit light of the same wavelength, are provided on the substrate 13, so the temperature characteristics of the laser light sources 21 and 71 can be made the same. Furthermore, the laser light sources 22 and 72, which emit light of the same wavelength, are provided on the substrate 14, so the temperature characteristics of the laser light sources 22 and 72 can be made the same. The laser light sources 21 and 22 emit light of different wavelengths.

[0082] The laser light sources 21, 22, 71, and 72 emit light of the same polarization. The laser light sources 21, 22, 71, and 72 emit, for example, S-polarized light. The radiation angles of the light emitted from the laser light sources 21, 22, 71, and 72 are, for example, the same. The laser light sources 21, 22, 71, and 72 are, for example, PCSELs.

[0083] The mirror 81 reflects the light emitted from the laser light source 71 in the first direction D1 in the second direction D2.

[0084] The mirror 82 transmits the light from the mirror 81 in the second direction D2 and reflects the light emitted from the laser light source 72 in the first direction D1 in the second direction D2. The mirrors 32 and 82 are dichroic mirrors.

[0085] Mirror 83 reflects the light from second mirror 32 in a direction perpendicular to first direction D1 and second direction D2. Mirror 84 reflects the light from mirror 82 in a direction perpendicular to first direction D1 and second direction D2. Mirror 85 reflects the light from mirror 84 in second direction D2. A λ / 2 plate 30 is provided in the optical path from mirror 84 to mirror 85. As a result, the light reflected by mirror 84 is converted, for example, from S-polarized light to P-polarized light.

[0086] The mirror 86 reflects the light reflected by the mirror 83 in the second direction D2, and transmits the light reflected by the mirror 85 in the second direction D2. The mirror 86 is a polarization beam combiner.

[0087] The focusing optical system 91 is provided between the laser light source 71 and the mirror 81. The focusing optical system 92 is provided between the laser light source 72 and the mirror 82. The focusing optical systems 91, 92 are, for example, focusing lenses. The distance between the laser light source 71 and the principal point of the focusing optical system 91 is, for example, the same as the distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41. The focal length of the focusing optical system 91 is, for example, the same as the focal length of the first focusing optical system 41. The distance between the laser light source 72 and the principal point of the focusing optical system 92 is, for example, the same as the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. The focal length of the focusing optical system 92 is, for example, the same as the focal length of the second focusing optical system 42.

[0088] In the laser module 400, the light emitted from the laser light sources 21, 22, 71, and 72 can be focused at a focusing point F by the focusing optical systems 41, 42, 91, and 92, respectively. Therefore, a high output can be achieved.

[0089] 2.3. Third Variant Next, a laser module according to a third modified example of this embodiment will be described with reference to the drawings. Fig. 8 is a diagram schematically showing a laser module 400 according to the third modified example of this embodiment.

[0090] Hereinafter, in the laser module 400 according to the third modified example of this embodiment, components having the same functions as the components of the laser module 100 according to this embodiment described above will be given the same symbols, and detailed descriptions thereof will be omitted.

[0091] As shown in FIG. 8, laser module 400 differs from the above-described laser module 100 in that it includes laser light sources 101, 102, 103, 104, 105, 106, 107, and 108, mirrors 111, 112, 113, 114, 115, 116, 117, 118, 121, 122, 123, and 124, and focusing optical systems 131, 132, 133, 134, 135, 136, 137, and 138.

[0092] For the sake of simplicity, Fig. 8 omits a portion of the spread of light on the optical path from the laser light source to the focal point F. This also applies to Figs. 9 to 11, which will be described later.

[0093] The laser light sources 101, 102, and 103 are provided on a first substrate 11. In the illustrated example, the laser light sources 21, 22, 101, 102, and 103 are arranged in this order in the Y-axis direction. The laser light sources 101, 102, and 103 emit light in a first direction D1. The optical axis of the light L1 emitted from the first laser light source 21, the optical axis of the light L2 emitted from the second laser light source 22, the optical axis of the light emitted from the laser light source 101, the optical axis of the light emitted from the laser light source 102, and the optical axis of the light emitted from the laser light source 103 are parallel to one another.

[0094] The laser light sources 21, 22, 101, 102, and 103 emit light beams of different wavelengths. The laser light sources 21, 22, 101, 102, and 103 emit light beams of the same polarization. The laser light sources 21, 22, 101, 102, and 103 emit, for example, S-polarized light beams.

[0095] The laser light sources 104, 105, 106, 107, and 108 are provided on the second substrate 12. In the illustrated example, the laser light sources 104, 105, 106, 107, and 108 are arranged in this order. and are arranged in the Y-axis direction. Laser light sources 104, 105, 106, 107, and 108 emit light in a first direction D1. The optical axis of the light emitted from laser light source 104, the optical axis of the light emitted from laser light source 105, the optical axis of the light emitted from laser light source 106, the optical axis of the light emitted from laser light source 107, and the optical axis of the light emitted from laser light source 108 are parallel to one another.

[0096] The laser light sources 104, 105, 106, 107, and 108 emit light beams of different wavelengths. The laser light sources 104, 105, 106, 107, and 108 emit light beams of the same polarization. The laser light sources 104, 105, 106, 107, and 108 emit, for example, P-polarized light beams.

[0097] The wavelength of the first light L1 emitted from the first laser light source 21 and the wavelength of the light emitted from the laser light source 104 may be the same. The wavelength of the second light L2 emitted from the second laser light source 22 and the wavelength of the light emitted from the laser light source 105 may be the same. The wavelength of the light emitted from the laser light source 101 and the wavelength of the light emitted from the laser light source 106 may be the same. The wavelength of the light emitted from the laser light source 102 and the wavelength of the light emitted from the laser light source 107 may be the same. The wavelength of the light emitted from the laser light source 103 and the wavelength of the light emitted from the laser light source 108 may be the same.

[0098] The radiation angles of the light beams emitted from the laser light sources 21, 22, 101, 102, 103, 104, 105, 106, 107, and 108 are, for example, the same. The laser light sources 21, 22, 101, 102, 103, 104, 105, 106, 107, and 108 are, for example, PCSELs.

[0099] The mirror 111 transmits the light L1 and L2 from the second mirror 32 in the second direction D2, and reflects the light emitted from the laser light source 101 in the first direction D1 in the second direction D2.

[0100] The mirror 112 transmits the light from the mirror 111 in the second direction D2, and reflects the light emitted from the laser light source 102 in the first direction D1 in the second direction D2.

[0101] The mirror 113 transmits the light from the mirror 112 in the second direction D2, and reflects the light emitted from the laser light source 103 in the first direction D1 in the second direction D2. The mirrors 32, 111, 112, and 113 are dichroic mirrors.

[0102] The mirror 114 reflects the light emitted from the laser light source 104 in the first direction D1 in the second direction D2.

[0103] The mirror 115 transmits the light reflected by the mirror 114 in the second direction D2, and reflects the light emitted from the laser light source 105 in the first direction D1 in the second direction D2.

[0104] The mirror 116 transmits the light from the mirror 115 in the second direction D2, and reflects the light emitted from the laser light source 106 in the first direction D1 in the second direction D2.

[0105] The mirror 117 transmits the light from the mirror 116 in the second direction D2, and reflects the light emitted from the laser light source 107 in the first direction D1 in the second direction D2.

[0106] Mirror 118 transmits the light from mirror 117 in the second direction D2, and reflects the light emitted from laser light source 108 in the first direction D1 in the second direction D2. Mirrors 114, 115, 116, 117, and 118 are dichroic mirrors.

[0107] Mirror 121 reflects the light from mirror 113 in a first direction D1. Mirror 122 reflects the light from mirror 118 in the direction opposite to first direction D1. Mirror 123 reflects the light from mirror 122 in a second direction D2.

[0108] Mirror 124 reflects the light from mirror 121 in the second direction D2, and transmits the light from mirror 123 in the second direction D2. Mirror 124 is a polarization beam combiner.

[0109] The focusing optical system 131 is provided between the laser light source 101 and the mirror 111. The distance between the laser light source 101 and the principal point of the focusing optical system 131 is shorter than the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. The focal length of the focusing optical system 131 is shorter than the focal length of the second focusing optical system 42.

[0110] The focusing optical system 132 is provided between the laser light source 102 and the mirror 112. The distance between the laser light source 102 and the principal point of the focusing optical system 132 is shorter than the distance between the laser light source 101 and the principal point of the focusing optical system 131. The focal length of the focusing optical system 132 is shorter than the focal length of the focusing optical system 131.

[0111] The focusing optical system 133 is provided between the laser light source 103 and the mirror 113. The distance between the laser light source 103 and the principal point of the focusing optical system 133 is shorter than the distance between the laser light source 102 and the principal point of the focusing optical system 132. The focal length of the focusing optical system 133 is shorter than the focal length of the focusing optical system 132.

[0112] The focusing optical system 134 is provided between the laser light source 104 and the mirror 114. The distance between the laser light source 104 and the principal point of the focusing optical system 134 is, for example, the same as the distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41. The focal length of the focusing optical system 134 is, for example, the same as the focal length of the first focusing optical system 41.

[0113] The focusing optical system 135 is provided between the laser light source 105 and the mirror 115. The distance between the laser light source 105 and the principal point of the focusing optical system 135 is, for example, the same as the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. The focal length of the focusing optical system 135 is, for example, the same as the focal length of the second focusing optical system 42.

[0114] The focusing optical system 136 is provided between the laser light source 106 and the mirror 116. The distance between the laser light source 106 and the principal point of the focusing optical system 136 is, for example, the same as the distance between the laser light source 101 and the principal point of the focusing optical system 131. The focal length of the focusing optical system 136 is, for example, the same as the focal length of the focusing optical system 131.

[0115] The focusing optical system 137 is provided between the laser light source 107 and the mirror 117. The distance between the laser light source 107 and the principal point of the focusing optical system 137 is, for example, the same as the distance between the laser light source 102 and the principal point of the focusing optical system 132. The focal length of the focusing optical system 137 is, for example, the same as the focal length of the focusing optical system 132.

[0116] The focusing optical system 138 is provided between the laser light source 108 and the mirror 118. The distance between the laser light source 108 and the principal point of the focusing optical system 138 is, for example, the same as the distance between the laser light source 103 and the principal point of the focusing optical system 133. The focal length of the focusing optical system 138 is, for example, the same as the focal length of the focusing optical system 133.

[0117] The light-collecting optical systems 131, 132, 133, 134, 135, 136, 137, and 138 are, for example, In the illustrated example, the light-collecting optical systems 131, 132, 133, 134, 135, 136, 137, and 138 are convex lenses.

[0118] In the laser module 400, the light emitted from the laser light sources 21, 22, 101, 102, 103, 104, 105, 106, 107, and 108 can be focused at a focusing point F by the focusing optical systems 41, 42, 131, 132, 133, 134, 135, 136, 137, and 138, respectively. This allows for higher output.

[0119] Note that the laser light sources 104, 105, 106, 107, and 108 may emit light of the same polarization as, for example, the laser light sources 21, 22, 101, 102, and 103. In this case, as shown in Fig. 9, a λ / 2 plate 30 is provided in the optical path from mirror 122 to mirror 123. This allows the light emitted from the laser light sources 104, 105, 106, 107, and 108 to be converted from S-polarized light to P-polarized light, for example.

[0120] Furthermore, the number of laser light sources and the number of mirrors are not particularly limited.

[0121] 2.4. Fourth Variant Next, a laser module according to a fourth modification of this embodiment will be described with reference to the drawings. Fig. 10 is a diagram schematically showing a laser module 500 according to the fourth modification of this embodiment.

[0122] Hereinafter, in the laser module 500 according to the fourth variant of this embodiment, components having the same functions as the components of the laser module 100 according to this embodiment described above will be given the same symbols, and detailed descriptions thereof will be omitted.

[0123] As shown in FIG. 10, the laser module 500 differs from the above-described laser module 100 in that it includes laser light sources 141, 142, 143, and 144, mirrors 151, 152, 153, 154, 155, 156, and 157, and focusing optical systems 161, 162, 163, and 164.

[0124] The laser light sources 141, 142, 143, and 144 are provided on the first substrate 11. In the illustrated example, the laser light sources 141, 21, 142, 22, 143, and 144 are arranged in this order in the Y-axis direction. The laser light sources 141, 142, 143, and 144 emit light in a first direction D1. The optical axis of the light L1 emitted from the first laser light source 21, the optical axis of the light L2 emitted from the second laser light source 22, the optical axis of the light emitted from the laser light source 141, the optical axis of the light emitted from the laser light source 142, the optical axis of the light emitted from the laser light source 143, and the optical axis of the light emitted from the laser light source 144 are parallel to one another.

[0125] The laser light sources 21 and 141 emit light of the same wavelength. The laser light sources 22 and 142 emit light of the same wavelength. The laser light sources 143 and 144 emit light of the same wavelength. The laser light sources 21, 22, and 143 emit light of different wavelengths.

[0126] The laser light sources 21, 22, and 144 emit light of a first polarization. The laser light sources 21, 22, and 144 emit, for example, P-polarized light. The laser light sources 141, 142, and 143 emit light of a second polarization different from the first polarization. The laser light sources 141, 142, and 143 emit, for example, S-polarized light.

[0127] The radiation angles of the light beams emitted from the laser light sources 21, 22, 141, 142, 143, and 144 are, for example, the same. CSEL.

[0128] The mirror 151 reflects the light emitted from the laser light source 141 in the first direction D1 in the second direction D2.

[0129] The mirror 152 transmits the light emitted in the first direction D1 from the first laser light source 21 in the first direction D1, and reflects the light reflected by the mirror 151 in the first direction D1. The mirror 152 is a polarization beam combiner.

[0130] The mirror 153 reflects the light emitted from the laser light source 142 in the first direction D1 in the second direction D2.

[0131] Mirror 154 transmits light emitted in first direction D1 from second laser light source 22 in first direction D1, and reflects light reflected by mirror 153 in first direction D1. Mirror 154 is a polarization beam combiner.

[0132] The mirror 155 reflects the light emitted from the laser light source 143 in the first direction D1 in the second direction D2.

[0133] Mirror 156 transmits light emitted in first direction D1 from laser light source 144 in first direction D1, and reflects light reflected by mirror 155 in first direction D1. Mirror 156 is a polarization beam combiner.

[0134] The first mirror 31 reflects the light from the mirror 152 in the second direction D2.

[0135] The second mirror 32 transmits the light from the first mirror 31 in the second direction D2, and reflects the light from the mirror 154 in the second direction D2. The second mirror 32 is a dichroic mirror.

[0136] The mirror 157 transmits the light from the second mirror 32 in the second direction D2, and reflects the light from the mirror 156 in the second direction D2. The mirror 157 is a dichroic mirror.

[0137] The light collecting optical system 161 is provided between the laser light source 141 and the mirror 151 .

[0138] The first focusing optical system 41 is provided between the first laser light source 21 and the mirror 152. The distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41 is shorter than the distance between the laser light source 141 and the principal point of the focusing optical system 161. The focal length of the first focusing optical system 41 is shorter than the focal length of the focusing optical system 161.

[0139] The focusing optical system 162 is provided between the laser light source 142 and the mirror 153. The distance between the laser light source 142 and the principal point of the focusing optical system 162 is shorter than the distance between the first laser light source 21 and the principal point H1 of the first focusing optical system 41. The focal length of the focusing optical system 162 is shorter than the focal length of the first focusing optical system 41.

[0140] The second focusing optical system 42 is provided between the second laser light source 22 and the mirror 154. The distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42 is shorter than the distance between the laser light source 142 and the principal point of the focusing optical system 162. The focal length of the second focusing optical system 42 is shorter than the focal length of the focusing optical system 162.

[0141] The focusing optical system 163 is provided between the laser light source 143 and the mirror 155. The distance between the laser light source 143 and the principal point of the focusing optical system 163 is shorter than the distance between the second laser light source 22 and the principal point H2 of the second focusing optical system 42. The focal length of the focusing optical system 163 is shorter than the focal length of the second focusing optical system 42.

[0142] The focusing optical system 164 is provided between the laser light source 144 and the mirror 156. The distance between the laser light source 144 and the principal point of the focusing optical system 164 is shorter than the distance between the laser light source 143 and the principal point of the focusing optical system 163. The focal length of the focusing optical system 164 is shorter than the focal length of the focusing optical system 163.

[0143] The light-collecting optical systems 161, 162, 163, and 164 are, for example, condenser lenses. In the illustrated example, the light-collecting optical systems 161, 162, 163, and 164 are convex lenses.

[0144] In the laser module 400, the light emitted from the laser light sources 21, 22, 141, 142, 143, and 144 can be focused at a focusing point F by the focusing optical systems 41, 42, 161, 162, 163, and 164, respectively. Therefore, high output can be achieved.

[0145] 11, a λ / 2 plate 30 is provided in the optical path from the first laser light source 21 to the first focusing optical system 41, the optical path from the second laser light source 22 to the second focusing optical system 42, and the optical path from the laser light source 144 to the focusing optical system 164. This allows the light emitted from the laser light sources 21, 22, 144 to be converted, for example, from S-polarized light to P-polarized light.

[0146] Furthermore, the number of laser light sources and the number of mirrors are not particularly limited.

[0147] 3. Laser processing machine Next, the laser processing machine according to this embodiment will be described with reference to the drawings. Fig. 12 is a diagram showing a schematic diagram of a laser processing machine 900 according to this embodiment.

[0148] As shown in FIG. 12, the laser processing machine 900 includes, for example, a laser module 100, an optical fiber 910, and a processing head 920.

[0149] The light emitted from the laser module 100 passes through an optical fiber 910 and is guided to a processing head 920 .

[0150] The laser processing machine 900 processes a workpiece W. Specifically, in the laser processing machine 900, a processing head 920 is moved relative to the workpiece W, and light is irradiated from the processing head 920 to process the workpiece W. The processing head 920 has lenses 922 and 924. The lenses 922 and 924 collect light emitted from the optical fiber 910 and guide it to the workpiece W. The material of the workpiece W is not particularly limited and may be metal, resin, or ceramic. Although not shown, the laser processing machine 900 may not include the optical fiber 910, and the laser module 100 may be incorporated into the processing head 920.

[0151] The use of the laser processing machine according to the present invention is not particularly limited. The laser processing machine according to the present invention may be a processing machine for cutting a workpiece W or drilling holes in the workpiece W. The laser processing machine according to the present invention may also be, for example, a laser cleaner that removes rust and the like from metal using laser light, a laser annealing device that heats the surface of metal or resin using laser light, or a 3D printer. It's okay to have it.

[0152] Furthermore, the laser processing machine according to the present invention may include a laser module other than the laser module 100 as long as it is a laser module according to the present invention.

[0153] 4. Experimental Example Next, a simulation was performed as an experimental example. Fig. 13 is a diagram for explaining the simulation. Fig. 14 is a table for explaining the simulation.

[0154] In the simulation, four light sources S1, S2, S3, and S4 were used, as shown in FIG. 13. The wavelengths of the light emitted from the light sources S1, S2, S3, and S4 were 1100 nm, 1000 nm, 900 nm, and 800 nm, respectively. The light emitted from the light sources S1, S2, S3, and S4 was incident on lenses T1, T2, T3, and T4, respectively. The conditions for the lenses T1, T2, T3, and T4 are as shown in FIG. 14. Note that "BK7" in FIG. 14 refers to borosilicate crown glass with a refractive index of 1.51680 at the d-line, such as "N-BK7" manufactured by SCHOTT. Other compatible glass materials, such as "S-BSL7" manufactured by OHARA, may also be used.

[0155] As shown in Fig. 14, the angles of light emitted from light sources S1, S2, S3, and S4 are approximately the same radiation angle between 11.7 and 11.8 degrees, and the light is collected so that the collection angles at the collection points are uniform at 5.9 degrees. Also, as shown in Fig. 14, as the distance from the light source to the front principal point increases, the focal lengths of the collecting lenses T1, T2, T3, and T4 increase. From the above, it has been verified by simulation that the features described in this invention are valid in principle.

[0156] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0157] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0158] The following can be derived from the above-described embodiment and modifications.

[0159] One aspect of the laser module is a first substrate; a first laser light source provided on a first plane of the first substrate and configured to emit first light in a first direction that is a direction perpendicular to the first plane; a second laser light source provided on the first plane and configured to emit second light in the first direction; a first mirror that reflects the first light emitted in the first direction from the first laser light source; a second mirror that transmits the first light reflected by the first mirror in a second direction different from the first direction and reflects the second light emitted from the second laser light source in the second direction; a first focusing optical system provided between the first laser light source and the first mirror; a second focusing optical system provided between the second laser light source and the second mirror; Including, a radiation angle of the first light emitted from the first laser light source and a radiation angle of the second light emitted from the second laser light source are the same; a distance between the first laser light source and a principal point of the first focusing optical system is greater than a distance between the second laser light source and a principal point of the second focusing optical system; an optical path length from the first laser light source to the second mirror is longer than an optical path length from the second laser light source to the second mirror; The focal length of the first focusing optical system is greater than the focal length of the second focusing optical system.

[0160] According to this laser module, the positions of the first laser light source and the second laser light source can be easily adjusted.

[0161] In one embodiment of the laser module, the first light and the second light are incident on the second mirror as light beams having different polarization directions; The second mirror may be a polarizing beam combiner.

[0162] According to this laser module, the first light and the second light can be multiplexed at the second mirror.

[0163] In one embodiment of the laser module, the first light and the second light have different wavelengths, The second mirror may be a dichroic mirror.

[0164] According to this laser module, the first light and the second light can be multiplexed at the second mirror.

[0165] In one embodiment of the laser module, a second substrate provided opposite to the first substrate; a third laser light source provided on a second plane of the second substrate and configured to emit third light in a third direction opposite to the first direction; a fourth laser light source provided on the second plane and configured to emit fourth light in the third direction; a third mirror that reflects the third light emitted from the third laser light source in the third direction; a fourth mirror that transmits the third light reflected by the third mirror in the second direction and reflects the fourth light emitted from the fourth laser light source in the second direction; a fifth mirror that reflects the first light and the second light from the second mirror in the second direction and transmits the third light and the fourth light from the fourth mirror in the second direction; may include:

[0166] This laser module can achieve high output.

[0167] In one embodiment of the laser module, the first light and the second light are incident on the fifth mirror as light of a first polarization, the third light and the fourth light are incident on the fifth mirror as light of a second polarization different from the first polarization, The fifth mirror may be a polarizing beam combiner.

[0168] This laser module can multiplex the first light, the second light, the third light, and the fourth light.

[0169] In one embodiment of the laser module, the first light and the second light are light of a first wavelength, the third light and the fourth light are light of a second wavelength different from the first wavelength, The fifth mirror may be a dichroic mirror.

[0170] This laser module can multiplex the first light, the second light, the third light, and the fourth light.

[0171] In one embodiment of the laser module, The first laser light source and the second laser light source may be photonic crystal surface emitting lasers.

[0172] According to this laser module, for example, the polarization directions of the first light and the second light can be adjusted by composite modulation.

[0173] One aspect of the laser processing machine is Includes laser module. [Explanation of symbols]

[0174] 11...first substrate, 11a...first plane, 12...second substrate, 12a...second plane, 13, 14...substrate, 21...first laser light source, 21a...exit surface, 22...second laser light source, 22a...exit surface, 23...third laser light source, 23a...exit surface, 24...fourth laser light source, 24a...exit surface, 30...λ / 2 plate, 31...first mirror, 32...second mirror, 33...third mirror, 34 ...fourth mirror, 35...fifth mirror, 36, 37, 38...mirrors, 41...first focusing optical system, 42...second focusing optical system, 50...casing, 61...first semiconductor layer, 62...first guide layer, 63...quantum well layer, 64...second guide layer, 65...second semiconductor layer, 66...transparent substrate, 67...first electrode, 68...second electrode, 68a...through hole, 69...opening, 71, 72...laser light source, 81, 82, 83, 84, 85, 86... mirrors, 91, 92... focusing optical system, 100... laser module, 101, 102, 103, 104, 105, 106, 107, 108... laser light source, 111, 112, 113, 114, 115, 116, 117, 118, 121, 122, 123, 124... mirrors, 131, 132, 133, 134, 135, 136, 137, 138... Condensing optical system, 141, 142, 143, 144... Laser light source, 151, 152, 153, 154, 155, 156, 157... Mirror, 161, 162, 163, 164... Condensing optical system, 200, 300, 400, 500... Laser module, 900... Laser processing machine, 910... Optical fiber, 920... Processing head, 922, 924... Lens

Claims

1. a first substrate; a first laser light source provided on a first plane of the first substrate and configured to emit first light in a first direction that is a direction perpendicular to the first plane; a second laser light source provided on the first plane and configured to emit second light in the first direction; a first mirror that reflects the first light emitted in the first direction from the first laser light source; a second mirror that transmits the first light reflected by the first mirror in a second direction different from the first direction and reflects the second light emitted from the second laser light source in the second direction; a first focusing optical system provided between the first laser light source and the first mirror; a second focusing optical system provided between the second laser light source and the second mirror; Including, a radiation angle of the first light emitted from the first laser light source and a radiation angle of the second light emitted from the second laser light source are the same, a distance between the first laser light source and a principal point of the first focusing optical system is greater than a distance between the second laser light source and a principal point of the second focusing optical system; an optical path length from the first laser light source to the second mirror is longer than an optical path length from the second laser light source to the second mirror; A laser module, wherein the focal length of the first focusing optical system is greater than the focal length of the second focusing optical system.

2. In claim 1, the first light and the second light are incident on the second mirror as light beams having different polarization directions; The laser module, wherein the second mirror is a polarization beam combiner.

3. In claim 1, the first light and the second light have different wavelengths, The laser module, wherein the second mirror is a dichroic mirror.

4. In claim 1, a second substrate provided opposite to the first substrate; a third laser light source provided on a second plane of the second substrate and configured to emit third light in a third direction opposite to the first direction; a fourth laser light source provided on the second plane and configured to emit fourth light in the third direction; a third mirror that reflects the third light emitted from the third laser light source in the third direction; a fourth mirror that transmits the third light reflected by the third mirror in the second direction and reflects the fourth light emitted from the fourth laser light source in the second direction; a fifth mirror that reflects the first light and the second light from the second mirror in the second direction and transmits the third light and the fourth light from the fourth mirror in the second direction; Including, the laser module.

5. In claim 4, the first light and the second light are incident on the fifth mirror as light of a first polarization, the third light and the fourth light are incident on the fifth mirror as light of a second polarization different from the first polarization, The laser module, wherein the fifth mirror is a polarization beam combiner.

6. In claim 4, the first light and the second light are light of a first wavelength, the third light and the fourth light are light of a second wavelength different from the first wavelength, The laser module, wherein the fifth mirror is a dichroic mirror.

7. In claim 1, A laser module, wherein the first laser light source and the second laser light source are photonic crystal surface-emitting lasers.

8. A laser processing machine comprising the laser module according to any one of claims 1 to 7.

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