Light emitting device

Abstract

To provide a light emitting device capable of reducing the deviation between the direction of travel of a laser beam emitted from a semiconductor laser element and the designed direction of travel.SOLUTION: A light emitting device comprises a substrate having a mounting surface, a semiconductor laser element supported by the mounting surface, a first mirror member supported by the mounting surface and having a first reflecting surface facing obliquely upward, a cover having an opposing surface facing the mounting surface of the substrate and a top surface located on the opposite side of the opposing surface and above the semiconductor laser element and the first mirror member, and a second mirror member supported by the top surface of the cover and having a second reflecting surface. The first reflecting surface reflects the laser beam to change the direction of the laser beam away from the mounting surface of the substrate, the cover transmits the laser beam reflected by the first reflecting surface, and the second reflecting surface reflects the laser beam reflected by the first reflecting surface and further changes the direction of the laser beam.SELECTED DRAWING: Figure 2F

Description

[Technical field]

[0001] The present disclosure relates to a light emitting device. [Background technology]

[0002] In recent years, with the increasing power output of semiconductor laser elements, technology is being developed that uses semiconductor laser elements not as excitation light sources but as light sources of laser light that directly irradiate materials for processing. This technology is called direct diode laser (DDL) technology.

[0003] The DDL technology uses a light emitting module equipped with multiple semiconductor laser elements. The light emitting module combines multiple laser beams obtained by emitting laser beams from each of the multiple semiconductor laser elements to emit high-power laser beam. When the traveling directions of the multiple laser beams are aligned in the same direction as designed, the multiple laser beams can be effectively combined. Patent Document 1 discloses an example of an optical component capable of reducing the deviation between the traveling direction of the laser beam emitted from the semiconductor laser element and the traveling direction as designed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 051836 Summary of the Invention [Problem to be solved by the invention]

[0005] A light emitting device capable of reducing the deviation between the traveling direction of laser light emitted from a semiconductor laser element and the traveling direction in design. [Means for solving the problem]

[0006] a first mirror member supported by the mounting surface, the first mirror member having a first reflective surface inclined with respect to the mounting surface and facing obliquely upward; a cover having an opposing surface facing the mounting surface of the substrate and an upper surface positioned opposite the opposing surface, the second mirror member being positioned above the semiconductor laser element and the first mirror member; and a second mirror member supported by the upper surface of the cover, the second mirror member having a second reflective surface, at least a portion of the second reflective surface being positioned above at least a portion of the first reflective surface, the semiconductor laser element being positioned to emit laser light toward the first reflective surface, the first reflective surface reflecting the laser light to change the traveling direction of the laser light in a direction away from the mounting surface of the substrate, the cover transmitting the laser light reflected by the first reflective surface, and the second reflective surface reflecting the laser light reflected by the first reflective surface to further change the traveling direction of the laser light. Effect of the Invention

[0007] According to the embodiments of the present disclosure, it is possible to realize a light emitting device capable of reducing the deviation between the traveling direction of laser light emitted from a semiconductor laser element and the designed traveling direction. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1A is a top view diagrammatically illustrating a configuration of a light emitting module according to an exemplary embodiment of the present disclosure. [Figure 1B] FIG. 1B is a side view diagrammatically illustrating a configuration of a light emitting module according to an exemplary embodiment of the present disclosure. [Figure 1C] FIG. 1C is another side view diagrammatically illustrating the configuration of the light emitting module according to the exemplary embodiment of the present disclosure. [Figure 1D] FIG. 1D is a top view diagrammatically illustrating a configuration of a modified example of the light emitting module according to the embodiment of the present disclosure. [Figure 2A]FIG. 2A is a perspective view that illustrates a schematic configuration of a light emitting device according to an exemplary embodiment of the present disclosure. [Figure 2B] FIG. 2B is an exploded perspective view of the light emitting device shown in FIG. 2A. [Figure 2C] FIG. 2C is another exploded perspective view of the light emitting device shown in FIG. 2A. [Figure 2D] FIG. 2D is a perspective view of a frame included in the light emitting device shown in FIG. 2C, as viewed from below. [Figure 2E] FIG. 2E is a top view of a configuration in which the second mirror member and the cover are omitted from the light emitting device shown in FIG. 2A. [Figure 2F] FIG. 2F is a cross-sectional view parallel to the YZ plane of the light emitting device shown in FIG. 2A. [Diagram 3] FIG. 3 is a diagram illustrating a schematic configuration of a DDL device according to an exemplary embodiment of the present disclosure. [Figure 4A] FIG. 4A is an exploded perspective view of a laser light source. [Figure 4B] FIG. 4B is a cross-sectional view of the laser light source parallel to the YZ plane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a light emitting device according to an embodiment of the present disclosure and a light emitting module including a plurality of light emitting devices will be described with reference to the drawings. Parts that appear in multiple drawings with the same reference numerals indicate the same or equivalent parts.

[0010] Furthermore, the embodiments described below are exemplified to embody the technical ideas of the present invention, and do not limit the present invention to the following. Furthermore, the description of the size, material, shape, relative arrangement, etc. of components is intended to be illustrative, and not to limit the scope of the present invention. The size and positional relationship of the components shown in each drawing may be exaggerated to make it easier to understand.

[0011] In this specification and claims, polygons such as triangles and quadrangles are referred to as polygons, including shapes in which the corners of the polygon have been processed by rounding, chamfering, removing corners, rounding, etc. Moreover, shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle parts of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while leaving the polygon as the base are included in the interpretation of "polygon" described in this specification and claims.

[0012] (Embodiment) [Light emitting module] First, referring to FIG. 1A to FIG. 1C, a configuration example of a light emitting module according to an embodiment of the present disclosure will be described. FIG. 1A is a top view that shows a schematic configuration of a light emitting module according to an exemplary embodiment of the present disclosure. FIG. 1B is a side view that shows a schematic configuration of a light emitting module according to an exemplary embodiment of the present disclosure. FIG. 1C is another side view that shows a schematic configuration of a light emitting module according to an exemplary embodiment of the present disclosure. In these figures, for reference, an X-axis, a Y-axis, and a Z-axis that are mutually orthogonal are shown. The direction of the arrow of the X-axis is referred to as the +X direction, and the opposite direction is referred to as the -X direction. When the ±X directions are not distinguished, they are simply referred to as the X direction. The same applies to the Y direction and the Z direction. In this specification, for ease of understanding, the +Y direction is referred to as the "upward" direction, and the -Y direction is referred to as the "downward" direction. This does not limit the orientation of the light emitting module when it is used, and the orientation of the light emitting module is arbitrary.

[0013] 1A to 1C includes a support base 60, a condenser lens 70, an optical fiber 80, a support member 82 that supports the optical fiber 80, a plurality of slow axis collimator lenses 92, a plurality of mirror members 94, and a plurality of light emitting devices 100. Each mirror member 94 has a reflective surface 94s.

[0014] As shown in FIG. 1B, the support base 60 is disposed on a reference plane Ref parallel to the XZ plane. The reference plane Ref is a reference plane of height in the light emitting module 200. As shown in FIG. 1A, the support base 60 includes a first portion 60-1 that supports a plurality of light emitting devices 100. The support base 60 further includes a plurality of second portions 60-2 supported by the first portion 60-1. Each of the second portions 60-2 supports a corresponding slow axis collimator lens 92 and mirror member 94. The support base 60 further includes a third portion 60-3 connected to the first portion 60-1. The third portion 60-3 supports a condenser lens 70 and an optical fiber 80.

[0015] The first portion 60-1 has a plurality of first placement surfaces 60s1 arranged in the X direction. A corresponding second portion 60-2 is disposed on each of the first placement surfaces 60s1. Each of the second portions 60-2 has a second placement surface 60s2. The third portion 60-3 has a third placement surface 60s3.

[0016] The heights of the first mounting surfaces 60s1 decrease stepwise along the +X direction as shown in FIG. 1B. The heights of the second mounting surfaces 60s2 decrease in the same manner. As shown in FIG. 1A, a corresponding light emitting device 100 is disposed on each of the first mounting surfaces 60s1. A corresponding slow axis collimator lens 92 and a mirror member 94 are disposed on each of the second mounting surfaces 60s2. When the slow axis collimator lens 92 and / or the mirror member 94 have a sufficiently large dimension in the Y direction, the slow axis collimator lens 92 and / or the mirror member 94 may be disposed on the first mounting surface 60s1 without the second portion 60-2. On the third mounting surface 60s3, a condenser lens 70 is disposed, and an optical fiber 80 is disposed via a support member 82.

[0017] In the example shown in FIG. 1B, the height of the third mounting surface 60s3 is greater than the minimum height of the first mounting surfaces 60s1 and less than the maximum height. The height of the third mounting surface 60s3 is also less than the minimum height of the second mounting surfaces 60s2. Depending on the dimension of the condenser lens 70 in the Y direction, the height of the third mounting surface 60s3 may be equal to or less than the minimum height of the first mounting surfaces 60s1. Alternatively, the height of the third mounting surface 60s3 may be equal to or greater than the maximum height of the first mounting surfaces 60s1.

[0018] In the example shown in FIG. 1A to FIG. 1C, the number of the light emitting devices 100 is four, and the number of the first mounting surfaces 60s1 is four, but is not limited to these numbers. The number of the light emitting devices 100 may be two, three, or five or more. As the number of the light emitting devices 100 increases, it becomes possible to obtain a laser light with a higher output. The number of the first mounting surfaces 60s1 may be two, three, five or more, and may be equal to or greater than the number of the light emitting devices 100.

[0019] The support base 60 may be formed of a ceramic selected from the group consisting of AlN, SiN, SiC, and alumina. Alternatively, the support base 60 may be formed of at least one metal material selected from the group consisting of Cu, Al, and Ag. The support base 60 may be formed of a metal matrix composite material in which diamond particles are dispersed in at least one metal material selected from the group consisting of Cu, Al, and Ag. The support base 60 may be integrally formed or may be an assembly of multiple parts. The multiple parts may be formed of the same material or different materials. For example, the first portion 60-1, the multiple second portions 60-2, and the third portion 60-3 may be integrally formed or may be formed independently of each other. Alternatively, the first portion 60-1 and the third portion 60-3 may be integrally formed, and the plurality of second portions 60-2 may be formed independently of the first portion 60-1 and the third portion 60-3.

[0020] The support base 60 is preferably made of a metal material selected from the group consisting of Cu, Al, and Ag, and is made of a single member. Metal materials have better heat dissipation properties than ceramics, and are soft and therefore easy to process.

[0021] The support base 60 functions as a support base on which the light emitting devices 100 are placed. The support base 60 may also function as a heat sink that transfers heat generated from the light emitting devices 100 to the outside to reduce excessive temperature rise of the light emitting devices 100. In this case, one or more flow paths for liquid cooling may be provided inside the support base 60. For example, water may be used as the liquid used for liquid cooling. Also, a fin structure for air cooling may be provided on the surface of the support base 60. Alternatively, when the support base 60 is placed on a separately prepared heat sink, the support base 60 may also function as a heat spreader that transfers heat generated from the light emitting devices 100 to the heat sink.

[0022] As shown in FIG. 1A and FIG. 1C, each light emitting device 100 emits a laser light L in the +Z direction. As shown in FIG. 1A, each slow axis collimating lens 92 collimates the laser light emitted from the corresponding light emitting device 100 and traveling in the +Z direction in the XZ plane. As shown in FIG. 1A and FIG. 1B, the reflecting surface 94s of each mirror member 94 reflects the collimated laser light L emitted from the corresponding light emitting device 100 and changes the traveling direction of the laser light L to the +X direction toward the condenser lens 70. The laser light L emitted from each light emitting device 100 is represented by a thick line with three arrows in the example shown in FIG. 1A, and is represented by a thick line with one arrow in the examples shown in FIG. 1B and FIG. 1C. In the example shown in FIG. 1A, the laser light L is represented by a thick line with three arrows in order to emphasize that the laser light L has a spread.

[0023] The condenser lens 70 has a fast axis condenser lens 70a and a slow axis condenser lens 70b. The fast axis condenser lens 70a may be, for example, a cylindrical lens having a uniform cross-sectional shape in the Z direction, and the slow axis condenser lens 70b may be, for example, a cylindrical lens having a uniform cross-sectional shape in the Y direction. The optical axis of each of the fast axis condenser lens 70a and the slow axis condenser lens 70b is parallel to the X direction. The condenser lens 70 may be formed of at least one light-transmitting material selected from the group consisting of, for example, glass, silicon, quartz, synthetic quartz, sapphire, transparent ceramics, silicone resin, and plastic.

[0024] The fast axis focusing lens 70a is arranged so that its focal point almost coincides with the light incident end 80a of the optical fiber 80. Similarly, the slow axis focusing lens 70b is arranged so that its focal point almost coincides with the light incident end 80a of the optical fiber 80. The focal length of the fast axis focusing lens 70a is longer than that of the slow axis focusing lens 70b. As shown in FIG. 1B, the fast axis focusing lens 70a converges the multiple laser beams L obtained by emitting the laser beams L from each of the multiple light emitting devices 100 on the light incident end 80a of the optical fiber 80 in the XY plane. As shown in FIG. 1A, the slow axis focusing lens 70b converges the laser beams L having a spread emitted from each of the multiple light emitting devices 100 on the light incident end 80a in the XZ plane.

[0025] As described above, the laser light L emitted in the +Z direction from each of the multiple light-emitting devices 100 is reflected in the +X direction by the corresponding reflecting surface 94s. The multiple laser light L thus obtained can be combined by the condenser lens 70 and made to enter the optical fiber 80.

[0026] As a result, the light emitting module 200 emits combined light obtained by combining the multiple laser lights L from the light emitting end 80b of the optical fiber 80. The output of the combined light is roughly equal to a value obtained by multiplying the output of the laser light L emitted from each light emitting device 100 by the number of light emitting devices 100. Therefore, by increasing the number of light emitting devices 100, the output of the combined light can be increased.

[0027] Next, a modified example of the light emitting module 200 according to the embodiment of the present disclosure will be described with reference to Fig. 1D. Fig. 1D is a top view showing a schematic configuration of a modified example of the light emitting module according to the embodiment of the present disclosure. The light emitting module 210 shown in Fig. 1D differs from the light emitting module 200 shown in Figs. 1A to 1C in the following three points.

[0028] The first point is that the light emitting module 210 includes a support base 62 instead of the support base 60. The shape of the support base 62 is different from the shape of the support base 60. The second point is that the light emitting module 210 further includes a plurality of light emitting devices 100-2, a plurality of slow axis collimating lenses 92b, and a plurality of mirror members 94b in addition to the plurality of light emitting devices 100-1, the plurality of slow axis collimating lenses 92a, and the plurality of mirror members 94a. Each mirror member 94a has a reflecting surface 94as, and each mirror member 94b has a reflecting surface 94bs. The third point is that the light emitting module 210 further includes a mirror member 94c, a 1 / 2 wavelength plate 96, and a polarizing beam splitter 98. The mirror member 94c has a reflecting surface 94cs.

[0029] The support base 62 includes a first portion 62-1 that supports the plurality of light emitting devices 100-1 and the plurality of light emitting devices 100-2. The support base 62 further includes a plurality of second portions 62-2 supported by the first portion 62-1. Each of the second portions 62-2 supports a corresponding slow axis collimating lens 92a, a slow axis collimating lens 92b, a mirror member 94a, and a mirror member 94b. The support base 62 further includes a third portion 62-3 that is connected to the first portion 62-1. The third portion 62-3 supports the condenser lens 70, the optical fiber 80, the mirror member 94c, the half-wave plate 96, and the polarizing beam splitter 98.

[0030] The first portion 62-1 has a plurality of first placement surfaces 60s1 arranged in the X direction. A corresponding second portion 62-2 is disposed on each of the first placement surfaces 60s1. Each of the second portions 62-2 has a second placement surface 60s2. The third portion 62-3 has a third placement surface 60s3.

[0031] The light emitting device 100-2, the slow axis collimator lens 92a, and the mirror member 94a have the same structures as the light emitting device 100, the slow axis collimator lens 92, and the mirror member 94 shown in FIG. 1A, respectively. The same is true for the light emitting device 100-2, the slow axis collimator lens 92b, and the mirror member 94b. The light emitting device 100-1, the slow axis collimator lens 92a, and the mirror member 94a are arranged in this order along the +Z direction, and the light emitting device 100-2, the slow axis collimator lens 92b, and the mirror member 94b are arranged in this order along the -Z direction. The arrangements of the light emitting device 100-1 and the light emitting device 100-2 are in a mutually inverted relationship in the Z direction. The same is true for the arrangements of the slow axis collimator lens 92a and the slow axis collimator lens 92b, and the arrangements of the mirror member 94a and the mirror member 94b.

[0032] Each light emitting device 100-1 and each light emitting device 100-2 are disposed on the corresponding first mounting surface 60s1. Each light emitting device 100-1 emits laser light La in the +Z direction, and each light emitting device 100-2 emits laser light Lb in the -Z direction. The polarization directions of the laser lights La and Lb are parallel to the X direction. Each slow axis collimating lens 92a, each slow axis collimating lens 92b, each mirror member 94a, and each mirror member 94b are disposed on the corresponding second mounting surface 60s2. Each slow axis collimating lens 92a collimates the laser light La emitted in the +Z direction from the corresponding light emitting device 100-1 in the XZ plane. Each slow axis collimating lens 92b collimates the laser light Lb emitted in the -Z direction from the corresponding light emitting device 100-2 in the XZ plane. The reflecting surface 94as of each mirror member 94a reflects the collimated laser beam La and changes the traveling direction of the laser beam La to the +X direction. The reflecting surface 94bs of each mirror member 94b reflects the collimated laser beam Lb and changes the traveling direction of the laser beam Lb to the +X direction.

[0033] The mirror member 94c, the half-wave plate 96, and the polarizing beam splitter 98 are disposed on the third mounting surface 60s3. The reflecting surface 94cs of the mirror member 94c reflects the laser light Lb traveling in the +X direction to change the traveling direction of the laser light Lb to the -Z direction. The half-wave plate 96 changes the polarization direction of the laser light Lb traveling in the -Z direction from the X direction to the Y direction. The polarizing beam splitter 98 transmits the laser light La traveling in the +X direction and having the polarization direction in the Z direction, and reflects the laser light Lb traveling in the -Z direction and having the polarization direction in the Y direction. The laser light La transmitted through the polarizing beam splitter 98 is converged by the condenser lens 70 to the light incident end 80a of the optical fiber 80. Similarly, the laser light Lb reflected by the polarizing beam splitter 98 is converged by the condenser lens 70 to the light incident end 80a of the optical fiber 80.

[0034] As a result, the light emitting module 210 emits a combined light in which the multiple laser lights La and the multiple laser lights Lb are combined, from the light emitting end 80b of the optical fiber 80. In the light emitting module 210 illustrated in Fig. 1D, the total number of the light emitting devices 100-1 and the light emitting devices 100-2 is twice the number of the light emitting devices 100, as compared with the light emitting module 200 illustrated in Fig. 1A. Therefore, the output of the combined light can be further increased.

[0035] In the light-emitting module 200, when the traveling directions of the multiple laser beams L are aligned in the +X direction as designed, the multiple laser beams L can be effectively combined by the focusing lens 70 and made to enter the optical fiber 80. The same is true in the light-emitting module 210 when the traveling directions of the multiple laser beams La and the multiple laser beams Lb are aligned in the +X direction as designed.

[0036] In the light-emitting module 200 according to the present embodiment, the light-emitting devices 100 are arranged on the first mounting surfaces 60s1 each having a different height, but the present invention is not limited to such a configuration. Alternatively, the light-emitting devices 100 may be used in a more general spatially coupled light-emitting module.

[0037] [Light emitting device] A configuration example of a light emitting device according to an embodiment of the present disclosure will be described below with reference to Figures 2A to 2F. According to the light emitting device according to the embodiment of the present disclosure, it is possible to reduce the deviation between the traveling direction of the laser light L and the designed traveling direction. In this specification, when the term "traveling direction" is simply described as "traveling direction of the laser light", the "traveling direction" refers to the actual traveling direction.

[0038] FIG. 2A is a perspective view that shows a schematic configuration of a light-emitting device according to an exemplary embodiment of the present disclosure. FIG. 2B is an exploded perspective view of the light-emitting device shown in FIG. 2A. The light-emitting device 100 shown in FIG. 2B includes a substrate 10, a laser light source 20, a first mirror member 30a, a second mirror member 30b, a frame body 40, a plurality of wires 40w, and a cover 50. The substrate 10 has a mounting surface 10us. The first mirror member 30a has a first reflecting surface 30as, and the second mirror member 30b has a second reflecting surface 30bs. The laser light source 20 is a chip-on-submount type semiconductor laser light source having a semiconductor laser element 22. The light-emitting device 100 may further include a protection element such as a Zener diode and / or a temperature measuring element for measuring an internal temperature such as a thermistor. FIG. 2C is another exploded perspective view of the light-emitting device 100 shown in FIG. 2A. In FIG. 2C, the plurality of wires 40w shown in FIG. 2B are omitted. Fig. 2D is a perspective view of the frame 40 included in the light emitting device 100 shown in Fig. 2C, seen from below. Fig. 2E is a top view of the light emitting device 100 shown in Fig. 2A, omitting the second mirror member 30b and the cover 50. Fig. 2F is a cross-sectional view parallel to the YZ plane of the light emitting device 100 shown in Fig. 2A.

[0039] As will be described in detail later, in the light emitting device 100 according to the present embodiment, as shown in FIG. 2F, the laser light L emitted from the laser light source 20 is reflected in this order by the first reflecting surface 30as and the second reflecting surface 30bs. With such a configuration, regardless of whether the traveling direction of the laser light L emitted from the laser light source 20 deviates from the +Z direction, which is the designed traveling direction, the traveling direction of the laser light L reflected by the first reflecting surface 30as and the second reflecting surface 30bs in this order can be directed to the +Z direction. The first reflecting surface 30as reflects the laser light L emitted from the laser light source 20 and changes the traveling direction of the laser light L to a direction away from the mounting surface 10us of the substrate 10. The second reflecting surface 30bs reflects the laser light L reflected by the first reflecting surface 30as and further changes the traveling direction of the laser light L to the +Z direction.

[0040] The position and orientation of the second mirror member 30b can be adjusted so that the laser light L reflected by the second reflecting surface 30bs travels in the +Z direction. By reflecting the laser light L reflected by the second reflecting surface 30bs by the reflecting surface 94s as shown in FIG. 1A, the traveling direction of the laser light L can be changed to the +X direction, which is the designed traveling direction. As a result, a plurality of laser lights L traveling in the +X direction can be effectively combined, and a high-power combined light can be output from the light-emitting module 200.

[0041] In a configuration in which the traveling direction of the laser light L incident on the reflecting surface 94s is not parallel to the designed +Z direction, the traveling direction of the laser light L reflected by the reflecting surface 94s deviates from the designed +X direction. Multiple laser lights L with such a deviation in traveling direction are not effectively combined even if the deviation angle is only a few degrees, and the output of the combined light may decrease.

[0042] In contrast, in this embodiment, it is possible to reduce the deviation between the traveling direction of the laser light L reflected by the first reflecting surface 30as and the second reflecting surface 30bs in this order and the +Z direction which is the designed traveling direction. As a result, it is possible to reduce the deviation between the traveling direction of the laser light L reflected by the reflecting surface 94s and the +X direction which is the designed traveling direction. The angle between the traveling direction of the laser light L and the designed traveling direction is preferably, for example, 1° or less, and more preferably 0.1° or less. In this specification, the angle between the two directions has a positive value and does not have a negative value.

[0043] In this embodiment, the designed traveling direction of the laser light L reflected by the first reflecting surface 30as and the second reflecting surface 30bs in this order is parallel to the +Z direction, and the designed traveling direction of the laser light L reflected by the reflecting surface 94s is parallel to the +X direction. However, the designed traveling directions are not limited to these directions.

[0044] In this specification, the direction in which the multiple first placement surfaces 60s1 are arranged is referred to as the "first direction", and the traveling direction of the laser light L reflected by the first reflecting surface 30as and the second reflecting surface 30bs in this order is referred to as the "second direction". The reference plane Ref is parallel to the first direction. In this embodiment, the first direction is the +X direction, and the second direction is the +Z direction, but is not limited to these directions. The second direction does not need to be perpendicular to the first direction as long as it intersects with the first direction.

[0045] The light emitting device 100 may be used for other purposes instead of being employed in the light emitting module 200 shown in FIGS. 1A and 1B.

[0046] Each component of the light emitting device 100 will be described below.

[0047] <Substrate 10> As shown in FIG. 2C, the substrate 10 has a mounting surface 10us and a lower surface 10Ls. The normal direction of the mounting surface 10us is the +Y direction. In this specification, the normal direction of a surface means a direction perpendicular to the surface and away from an object having the surface. In the example shown in FIG. 2C, the substrate 10 has a rectangular flat plate shape, but is not limited to this shape. The substrate 10 may have, for example, a polygonal, circular or elliptical flat plate shape. The lower surface 10Ls of the substrate 10 is bonded to the first mounting surface 60s1 of the support base 60 via an inorganic bonding member such as a solder material.

[0048] The substrate 10 may be formed of, for example, a material having a thermal conductivity of 10 W / m·K or more and 2000 W / m·K or less. The substrate 10 having such high thermal conductivity allows the heat generated from the laser light source 20 during operation to be effectively transferred to the support base 60 shown in FIGS. 1A to 1C via the substrate 10. The substrate 10 may be formed of, for example, the same material as the support base 60. The dimension of the substrate 10 in the X direction may be, for example, 1000 μm or more and 10000 μm or less, the dimension in the Y direction may be, for example, 100 μm or more and 5000 μm or less, and the dimension in the Z direction may be, for example, 1000 μm or more and 20000 μm or less.

[0049] <Laser light source 20> As shown in FIG. 2C, the laser light source 20 is supported by the mounting surface 10us of the substrate 10. The laser light source 20 includes a submount 21, an end-emission type semiconductor laser element 22 supported by the submount 21, a lens support member 23, and a fast-axis collimating lens 24. The semiconductor laser element 22 is supported by the mounting surface 10us of the substrate 10 via the submount 21. The semiconductor laser element 22 is disposed so as to emit laser light L toward the first reflecting surface 30as. The lens support member 23 has a shape that straddles the semiconductor laser element 22. The lens support member 23 supports the fast-axis collimating lens 24 by its end surface. The components of the laser light source 20 may be treated as components of the light-emitting device 100.

[0050] The semiconductor laser element 22 emits laser light L from a rectangular end face. When the end face extends in the X direction and is a plane parallel to the XY plane, the laser light L emitted from the semiconductor laser element 22 in the +Z direction spreads relatively fast in the YZ plane and spreads relatively slow in the XZ plane. The fast axis direction of the laser light L is parallel to the Y direction, and the slow axis direction is parallel to the X direction.

[0051] The laser light source 20 emits a laser light that is emitted from a semiconductor laser element 22 and transmitted through a fast axis collimating lens 24. The laser light L emitted from the laser light source 20 is collimated in the YZ plane, but is not collimated in the XZ plane. In this specification, "collimate" means not only making the laser light L parallel, but also reducing the spread angle of the laser light L. A specific configuration of the laser light source 20 will be described later.

[0052] The semiconductor laser element 22 included in the laser light source 20 is sealed by the substrate 10, the frame 40, and the cover 50, as shown in FIG. 2F. This sealing is preferably airtight. The effect of airtight sealing increases as the wavelength of the laser light emitted from the semiconductor laser element 22 becomes shorter. This is because, in a configuration in which the emission surface of the semiconductor laser element 22 is exposed to the outside air without airtight sealing, the shorter the wavelength of the laser light, the higher the possibility that the deterioration of the emission surface during operation due to dust collection increases.

[0053] A surface-emitting semiconductor laser element such as a Vertical-Cavity Surface-Emitting Laser (VCSEL) element may be used instead of the edge-emitting semiconductor laser element 22. The surface-emitting semiconductor laser element is disposed so that the laser light emitted from the semiconductor laser element travels in the +Z direction.

[0054] <First Mirror Member 30a and Second Mirror Member 30b> As shown in FIG. 2C, the first mirror member 30a is supported by the mounting surface 10us of the substrate 10. The first mirror member 30a has a uniform cross-sectional shape in the X direction. The cross-sectional shape is roughly triangular. The first mirror member 30a has a lower surface, a rear surface, and a slope connecting the lower surface and the rear surface. The lower surface is parallel to the XZ plane, and the rear surface is parallel to the XY plane. The normal direction of the slope is a direction parallel to the YZ plane, and forms an acute angle with the +Y direction and an acute angle with the -Z direction. The angle between the lower surface of the first mirror member 30a and the slope is 45°, but is not limited to this angle and may be, for example, 30° to 60°.

[0055] The first mirror member 30a has a first reflecting surface 30as on the inclined surface. The first reflecting surface 30as is inclined with respect to the mounting surface 10us of the substrate 10 and faces obliquely upward. In this specification, obliquely upward means a direction that forms an angle of 30° to 60° with the +Y direction. If the first reflecting surface 30as can receive the laser light L emitted from the laser light source 20 and the normal direction of the first reflecting surface 30as is a direction that forms an angle of 30° to 60° with the +Y direction, the normal direction of the first reflecting surface 30as may or may not be parallel to the YZ plane.

[0056] As shown in Fig. 2F, the first reflecting surface 30as reflects the laser light L emitted from the laser light source 20 and changes the traveling direction of the laser light L to a direction away from the mounting surface 10us of the substrate 10. The angle between the direction in which the laser light L leaves the mounting surface 10us of the substrate 10 and the normal direction of the mounting surface 10us can be, for example, 0° or more and 5° or less. Since the angle has a tolerance of 5°, the position and orientation of the first mirror member 30a do not need to be adjusted as strictly as the position and orientation of the second mirror member 30b.

[0057] As shown in FIG. 2C, the second mirror member 30b is supported by the upper surface 50us of the cover 50. The second mirror member 30b has a uniform cross-sectional shape in the X direction. The cross-sectional shape is approximately trapezoidal. The second mirror member 30b has an upper surface, a lower surface, and a slope connecting the upper surface and the lower surface. Each of the upper surface and the lower surface is parallel to the XZ plane. The dimension of the lower surface in the X direction is equal to the dimension of the upper surface in the X direction. On the other hand, the dimension of the lower surface in the Z direction is smaller than the dimension of the upper surface in the Z direction. The normal direction of the slope is a direction parallel to the YZ plane, and forms an acute angle with the -Y direction and an acute angle with the +Z direction. The angle between the upper surface of the second mirror member 30b and the slope is 45°, but is not limited to this angle and may be, for example, 30° to 60°. The angle between the upper surface and the inclined surface of the second mirror member 30b may be equal to or different from the angle between the lower surface and the inclined surface of the first mirror member 30a.

[0058] The second mirror member 30b has a second reflecting surface 30bs on the inclined surface. At least a part of the second reflecting surface 30bs is located above at least a part of the first reflecting surface 30as. As shown in FIG. 2F, the second reflecting surface 30bs reflects the laser light L reflected by the first reflecting surface 30as, and changes the traveling direction of the laser light L to the +Z direction.

[0059] As shown in FIG. 2F, a resin layer 32 is present between the lower surface of the second mirror member 30b and the upper surface 50us of the cover 50. In a state where the lower surface of the second mirror member 30b is in contact with the upper surface 50us of the cover 50 via the uncured resin, the resin is cured to form the resin layer 32. The resin may be, for example, a thermosetting resin that is cured by heating, or a photocurable resin that is cured by irradiation with ultraviolet light or visible light. Before curing the resin, the following active alignment is performed. That is, in a state where the laser light source 20 emits the laser light L, the position and orientation of the second mirror member 30b are appropriately adjusted so that the second reflecting surface 30bs changes the traveling direction of the laser light L to the +Z direction. Such an adjustment may be performed while the second mirror member 30b is held by a holding device after the light emitting device 100 is placed on the first mounting surface 60s1 of the support base 60 shown in FIGS. 1A to 1C.

[0060] The traveling direction of the laser light L can be adjusted by rotating the second mirror member 30b about the X-axis or Y-axis as a rotation axis to change its orientation. The traveling direction of the laser light L can be changed up and down by rotating the second mirror member 30b about the X-axis as a rotation axis. The traveling direction of the laser light L can be changed left and right by rotating the second mirror member 30b about the Y-axis as a rotation axis, with the traveling direction of the laser light L being the front direction.

[0061] Furthermore, by changing the position of the second mirror member 30b in the Z direction, the height of the optical axis of the laser light L can be adjusted. By shifting the second mirror member 30b along the +Z direction, the height of the optical axis of the laser light L can be reduced, and by shifting the second mirror member 30b along the -Z direction, the height of the optical axis of the laser light L can be increased. In this specification, the "optical axis of the laser light" means the axis passing through the center of the far-field pattern of the laser light. The laser light traveling on the optical axis shows a peak intensity in the light intensity distribution of the far-field pattern.

[0062] Here, unlike the present embodiment, a configuration in which the second mirror member 30b is fixed to the upper surface 50us of the cover 50 without adjusting the position and orientation is taken as an example. Even with such a configuration, in the light-emitting module 200 shown in FIG. 1A to FIG. 1C, by disposing a wedge between the second mirror member 30b and the slow-axis collimator lens 92, the traveling direction of the laser light L reflected by the second reflecting surface 30bs can be directed to the +Z direction. The wedge has a light incident surface and a light reflecting surface located on opposite sides to each other. The normal direction of the light incident surface is parallel to the -Z direction, and the normal direction of the light exit surface is a direction parallel to the YZ plane, forms an acute angle with the +Y direction or the -Y direction, and forms an acute angle with the +Z direction. Due to refraction at the light incident surface and the light incident surface that are not parallel to each other, the wedge can change the traveling direction of the laser light L passing through it. However, when using wedges, in order to direct the propagation direction of the laser light L in the +Z direction, it is necessary to prepare multiple wedges having different normal directions of the light emitting surface, and select from the multiple wedges a wedge whose normal direction to the light emitting surface is in an appropriate direction.

[0063] In contrast, in this embodiment, by arranging the second mirror member 30b at an appropriate position and orientation, the traveling direction of the laser light L reflected by the second reflecting surface 30bs can be directed to the +Z direction regardless of whether the traveling direction of the laser light L emitted from the laser light source 20 deviates from the +Z direction. In this embodiment, it is not necessary to prepare a plurality of second mirror members 30b having different angles between the top surface and the inclined surface and to select a second mirror member 30b with an appropriate angle from the plurality of second mirror members 30b.

[0064] The mirror members 30a and 30b shown in FIG. 2B and FIG. 2C, the mirror member 94 shown in FIG. 1A to FIG. 1C, and the mirror members 94a to 94c shown in FIG. 1D may include, for example, a base having an inclined surface and a reflection surface separately formed on the inclined surface. The base may be formed of at least one selected from the group consisting of glass, quartz, synthetic quartz, sapphire, ceramics, plastic, silicon, metal, silicone resin, and dielectric material. The reflection surface may be formed of a reflective material such as a dielectric multilayer film and a metal material. This reflection surface corresponds to the first reflection surface 30as and the second reflection surface 30bs shown in FIG. 2B, the reflection surface 94s shown in FIG. 1A, and the reflection surfaces 94as to 94cs shown in FIG. 1D.

[0065] Alternatively, the first mirror member 30a, the second mirror member 30b, and the mirror members 94, 94a to 94c may each have a base having an inclined surface, and the base may be made of the above-mentioned reflective material. In this case, the inclined surface of the base corresponds to the first reflecting surface 30as, the second reflecting surface 30bs, and the reflecting surfaces 94s, 94as to 94cs.

[0066] <Frame 40> The frame 40 is located around the mounting surface 10us of the substrate 10 as shown in FIG. 2B, and supports the cover 50 as shown in FIG. 2A. The frame 40 surrounds the laser light source 20 and the first mirror member 30a when viewed from the +Y direction, i.e., when viewed from above, as shown in FIG. 2B. The frame 40 has a protruding portion 40p protruding inward from the inner surface as shown in FIG. 2C. In the example shown in FIG. 2E, the protruding portion 40p protrudes toward both side surfaces and the back surface of the submount 21. The protruding portion 40p may further protrude toward the front surface of the submount 21. The protruding portion 40p may protrude only on both side surfaces. The front surface of the submount 21 is located on the same side as the emission surface of the semiconductor laser element 22, and the back surface of the submount 21 is located on the opposite side to the emission surface of the semiconductor laser element 22. The both side surfaces of the submount 21 connect the front surface and the back surface of the submount 21.

[0067] As shown in Fig. 2C, the frame 40 has a first upper surface 40us1 and a second upper surface 40us2. The second upper surface 40us2 is the upper surface of the protruding portion 40p, is located below the first upper surface 40us1, and is surrounded by the first upper surface 40us1 in a top view. As shown in Fig. 2E, the second upper surface 40us2 has a roughly U-shape.

[0068] The first upper surface 40us1 is provided with a first bonding region 44a and an outer region 46 surrounding the first bonding region 44a. Each of the first bonding region 44a and the outer region 46 has a generally rectangular ring shape. The first bonding region 44a improves the bonding strength when the cover 50 and the frame body 40 are bonded via an inorganic bonding member such as a solder material. The outer region 46 prevents the inorganic bonding member bonding the cover 50 from flowing out beyond the outer region 46. The first bonding region 44a and the outer region 46 surround the laser light source 20 and the first mirror member 30a in a top view, as shown in FIG. 2E. The first upper surface 40us1 is further provided with a first conductive region 42a and a second conductive region 42b that are electrically insulated from each other in the -Z direction from the first bonding region 44a and the outer region 46.

[0069] The second upper surface 40us2 is provided with a third conductive region 42c and a fourth conductive region 42d that are electrically insulated from each other. The third conductive region 42c is electrically connected to the first conductive region 42a via an internal wiring, and the fourth conductive region 42d is electrically connected to the second conductive region 42b via an internal wiring. As shown in FIG. 2E, in a top view, the laser light source 20 and the first mirror member 30a are located between a portion of the third conductive region 42c that extends in the Z direction and a portion of the fourth conductive region 42d that extends in the Z direction. The third conductive region 42c is electrically connected to the semiconductor laser element 22 via the upper surface of the submount 21 and some of the wires 40w shown in FIG. 2B. The fourth conductive region 42d is electrically connected to the semiconductor laser element 22 via the remaining wires 40w shown in FIG. 2B. Therefore, by applying a voltage between the first conductive region 42a and the second conductive region 42b, it is possible to supply power to the laser light source 20.

[0070] As shown in FIG. 2D, the frame 40 further has a first lower surface 40Ls1 and a second lower surface 40Ls2. The second lower surface 40Ls2 partially has the lower surface of the protruding portion 40p, is located above the first lower surface 40Ls1, and is surrounded by the first lower surface 40Ls1 when viewed from the -Y direction, i.e., when viewed from below. The second lower surface 40Ls2 has a generally rectangular ring shape. A part or the whole of the substrate 10 shown in FIG. 2C is accommodated in a space surrounded by the step between the first lower surface 40Ls1 and the second lower surface 40Ls2. When viewed through the frame 40, the outer periphery of the second lower surface 40Ls2 surrounds the outer periphery of the mounting surface 10us of the substrate 10 when viewed from above, and the inner periphery of the second lower surface 40Ls2 is surrounded by the outer periphery of the mounting surface 10us of the substrate 10 when viewed from above.

[0071] The entire first lower surface 40Ls1 is provided with a second bonding region 44b. The second bonding region 44b improves the bonding strength when the support base 60 and the frame body 40 shown in FIG. 1A to FIG. 1C are bonded via an inorganic bonding member such as a solder material. The entire second lower surface 40Ls2 is provided with a third bonding region 44c. The third bonding region 44c is bonded to the peripheral region of the mounting surface 10us of the substrate 10 via an inorganic bonding member such as a brazing material. The third bonding region 44c improves the bonding strength when the substrate 10 and the frame body 40 are bonded via an inorganic bonding member. The melting point of the brazing material is higher than the melting point of the solder material. Therefore, when the substrate 10 and the frame body 40 are bonded by heating the brazing material, and then the substrate 10 and the laser light source 20 are bonded by heating the solder material, the possibility that the substrate 10 and the frame body 40 will come off due to the heat applied to the solder material can be reduced.

[0072] In the example shown in FIG. 2D, the second bonding region 44b is provided over the entire first lower surface 40Ls1, but the second bonding region 44b may be provided on a part of the first lower surface 40Ls1. Similarly, in the example shown in FIG. 2D, the third bonding region 44c is provided over the entire second lower surface 40Ls2, but the third bonding region 44c may be provided on a part of the second lower surface 40Ls2. Alternatively, the second bonding region 44b may not be provided on the first lower surface 40Ls1, and the third bonding region 44c may not be provided on the second lower surface 40Ls2. When the second bonding region 44b is not provided on the first lower surface 40Ls1, the frame 40 and the supporting base 60 are not bonded, and the substrate 10 and the supporting base 60 are bonded only by the lower surface 10Ls of the substrate 10.

[0073] 2F, the first lower surface 40Ls1 of the frame 40 is located on the same plane as the lower surface 10Ls of the substrate 10. The first lower surface 40Ls1 of the frame 40 may be located above the lower surface 10Ls of the substrate 10. Alternatively, the first lower surface 40Ls1 of the frame 40 may be located below the lower surface 10Ls of the substrate 10 as long as it does not interfere with bonding the substrate 10 and the supporting base 60 via an inorganic bonding member.

[0074] 1A and 1B, the frame 40 may be made of the above-mentioned ceramics. The dimension of the frame 40 in the X direction may be, for example, 3 mm or more and 15 mm or less, the maximum dimension in the Y direction may be, for example, 1 mm or more and 5 mm or less, and the dimension in the Z direction may be, for example, 3 mm or more and 30 mm or less.

[0075] The conductive regions 42a-42d, the bonding regions 44a-44c, and the outer region 46 may be formed of at least one metal material selected from the group consisting of Ag, Cu, W, Au, Ni, Pt, and Pd. The conductive regions 42a-42d, the bonding region 44a, and the outer region 46 may be formed by providing a metal film on the entire upper surfaces 40us1 and 40us2 and patterning the metal film by etching, for example.

[0076] <Cover 50> As shown in FIG. 2B, the cover 50 has an upper surface 50us and a lower surface 50Ls. The lower surface 50Ls of the cover 50 faces the mounting surface 10us of the substrate 10, and the upper surface 50us of the cover 50 is located on the opposite side of the lower surface 50Ls of the cover 50. In this specification, the lower surface 50Ls of the cover 50 is also referred to as the "opposing surface." The cover 50 is located above the semiconductor laser element 22 and the first mirror member 30a. The cover 50 transmits the laser light L reflected by the first reflecting surface 30as.

[0077] The cover 50 has a light-shielding film 52 at least around a light-transmitting region 50t of the lower surface 50Ls that transmits the laser light L. In the example shown in Fig. 2C, the light-transmitting region 50t has a rectangular shape, but is not limited to this shape. The shape of the light-transmitting region 50t may be, for example, a circular shape or an elliptical shape.

[0078] Alternatively, the cover 50 may have the light-shielding film 52 in at least a part of the periphery of the light-transmitting region 50t in the lower surface 50Ls. For example, when a part of the edge of the light-transmitting region 50t coincides with a part of the edge of the lower surface 50Ls, the light-shielding film 52 may be provided in at least a part of the following region of the lower surface 50Ls. This region is a region of the lower surface 50Ls that is adjacent to the remaining part of the edge of the light-transmitting region 50t other than the above-mentioned part.

[0079] The light-shielding film 52 reduces the possibility that stray light other than the laser light L generated inside the light-emitting device 100 leaks to the outside of the light-emitting device 100. The light-shielding film 52 further reduces the possibility that ultraviolet light or visible light reaches the laser light source 20 when the resin layer 32 shown in FIG. 2F is formed by irradiation with ultraviolet light or visible light. The light-shielding film 52 further reduces the possibility that return light of the laser light L emitted to the outside of the light-emitting device 100 reaches the laser light source 20. If irradiation by ultraviolet light or visible light or return light can be reduced, the laser light source 20 is less likely to be damaged.

[0080] 2C, the light-shielding film 52 is provided on the entire lower surface 50Ls except for the light-transmitting region 50t. The light-shielding film 52 thus provided further reduces the possibility that the stray light leaks out of the light-emitting device 100 and that the ultraviolet light or visible light or the return light reaches the laser light source 20.

[0081] Of the cover 50, not only the light-transmitting region 50t but also a portion overlapping the light-transmitting region 50t in a top view transmits the laser light L. Of the cover 50, the portion that transmits the laser light L may have a transmittance of, for example, 60% or more, and preferably a transmittance of 80% or more, for the laser light L. Of the remaining portion of the cover 50, it may or may not have such light-transmitting properties.

[0082] The cover 50 may be formed of the above-mentioned light-transmitting material, for example, similar to the condenser lens 70 shown in Figures 1A and 1B. The dimension of the cover 50 in the X direction may be, for example, 3 mm or more and 15 mm or less, the dimension in the Y direction may be, for example, 0.1 mm or more and 1.5 mm or less, and the dimension in the Z direction may be, for example, 1 mm or more and 20 mm or less.

[0083] The light-shielding film 52 may be formed of the above-mentioned metal material, similar to the conductive regions 42a-42d, the bonding regions 44a-44c, and the outer region 46. The light-shielding film 52 may be formed, similar to the conductive regions 42a-42d, the bonding region 44a, and the outer region 46, by providing a metal film on the entire lower surface 50Ls of the cover 50 and patterning the metal film by etching.

[0084] The peripheral region of the light-shielding film 52 is joined via an inorganic bonding member such as a solder material to the first bonding region 44a provided on the first upper surface 40us1 of the frame body 40. When the light-shielding film 52 is made of the above-mentioned metal material, the light-shielding film 52 improves the bonding strength when the cover 50 and the frame body 40 are joined via the inorganic bonding member.

[0085] In the examples shown in Figs. 2A to 2C, the cover 50 has a flat plate shape, but is not limited to this shape. In a configuration in which the substrate 10 has a flat plate shape without the frame body 40, the cover 50 may have a box shape with an open lower part instead of a flat plate shape. The cover 50 having such a shape is supported by the mounting surface 10us of the substrate 10 and houses the laser light source 20 and the first mirror member 30a. In addition, the cover 50 having a box shape with an open lower part and the frame body 40 may be joined together, and the laser light source 20 and the first mirror member 30a may be surrounded by the cover 50 and the frame body 40.

[0086] As described above, according to the present embodiment, it is possible to realize a light emitting device 100 capable of reducing the deviation between the traveling direction of the laser light L and the designed traveling direction. By employing such a light emitting device 100 in the light emitting module 200 shown in Fig. 1A to Fig. 1C, it is possible to effectively combine the multiple laser lights L obtained by emitting the laser light L from each of the multiple light emitting devices 100 and input the combined light to the optical fiber 80.

[0087] The light emitting device 100 can be manufactured, for example, as follows. In the first step, the substrate 10, the laser light source 20, the first mirror member 30a, the second mirror member 30b, the frame body 40, the multiple wires 40w, and the cover 50 are prepared. In the next step, the frame body 40 is bonded to the substrate 10. In the next step, the laser light source 20 and the first mirror member 30a are provided on the mounting surface 10us of the substrate 10. In the next step, multiple wires 40w for supplying power to the laser light source 20 are provided. In the next step, the cover 50 is bonded to the frame body 40. In the next step, active alignment is performed in a state in which the lower surface of the second mirror member 30b is in contact with the upper surface 50us of the cover 50 via the uncured resin. In the next step, the resin is cured to form a resin layer 32 between the second mirror member 30b and the cover 50.

[0088] [DDL device] Next, a configuration example of a DDL device according to an embodiment of the present disclosure will be described with reference to FIG. 3. FIG. 3 is a diagram showing a schematic configuration of a DDL device according to an exemplary embodiment of the present disclosure. The DDL device 1000 shown in FIG. 3 includes a plurality of light-emitting modules 200 according to this embodiment, a processing head 300, and an optical transmission fiber 250 that connects the light-emitting modules 200 to the processing head 300. In the example shown in FIG. 3, the number of light-emitting modules 200 is four, but is not limited to this number. The number of light-emitting modules 200 may be one, two, three, or five or more.

[0089] The number of light emitting devices 100 included in each light emitting module 200 is determined according to the required optical output or irradiance. The wavelength of the laser light emitted from the light emitting device 100 can also be selected according to the material to be processed. For example, when processing metals such as copper, brass, and aluminum, a semiconductor laser element having a central wavelength in the range of 350 nm to 550 nm can be suitably adopted. The wavelength of the laser light emitted from each light emitting device 100 does not need to be the same, and laser lights with different central wavelengths may be superimposed. In addition, the effect of the present invention can be obtained even when using laser light having a central wavelength outside the range of 350 nm to 550 nm.

[0090] In the example shown in FIG. 3, an optical fiber 80 extends from each of the multiple light-emitting modules 200. The multiple optical fibers 80 thus obtained are coupled to an optical transmission fiber 250 by an optical multiplexer 230. The optical multiplexer 230 may be, for example, a TFB (Tapered Fiber Bundle). The processing head 300 converges and irradiates the laser light emitted from the light-emitting end of the optical fiber 80 onto the object 400. In the case where one DDL device 1000 includes M light-emitting modules 200, and each light-emitting module 200 includes N light-emitting devices 100, if the optical output of one light-emitting device 100 is P watts, a laser beam having an optical output of P×N×M watts at most can be converged onto the object 400. Here, N is an integer of 2 or more, and M is a positive integer. For example, if P=20 watts, N=22, and M=12, an optical output exceeding 5 kilowatts can be realized.

[0091] [Configuration of laser light source 20] Next, an example of the configuration of the laser light source 20 shown in Fig. 2C will be described with reference to Fig. 4A and Fig. 4B. Fig. 4A is an exploded perspective view of the laser light source 20. Fig. 4B is a cross-sectional view of the laser light source 20 parallel to the YZ plane. Each component of the laser light source 20 will be described below.

[0092] As shown in FIG. 4A, the submount 21 has an upper surface 21us and a lower surface 21Ls that are parallel to the XZ plane. A metal film is provided on each of the upper surface 21us and the lower surface 21Ls. The metal film provided on the upper surface 21us improves the bonding strength when the semiconductor laser element 22 and the lens support member 23 are bonded to the submount 21 with an inorganic bonding member. The metal film provided on the upper surface 21us may also be used to supply power to the semiconductor laser element 22. The metal film provided on the lower surface 21Ls improves the bonding strength when the substrate 10 and the laser light source 20 shown in FIG. 2C are bonded via an inorganic bonding member. The metal film provided on each of the upper surface 21us and the lower surface 21Ls also helps to transfer heat generated by the semiconductor laser element 22 during operation to the substrate 10 via the submount 21. Submount 21 may be formed, for example, from the aforementioned ceramics, metallic materials, or metal matrix composite materials, similar to supporting substrate 60 shown in FIGS. 1A and 1B.

[0093] As shown in FIG. 4A, the semiconductor laser element 22 is supported by the upper surface 21us of the submount 21. The semiconductor laser element 22 has an emission surface 22e, one of two end surfaces intersecting in the Z direction, and emits laser light in the +Z direction from the emission surface 22e. As the laser light travels in the +Z direction, it spreads at different speeds in the YZ plane and the XZ plane. The laser light spreads relatively quickly in the YZ plane and relatively slowly in the XZ plane. When not collimated, the spot of the laser light has an elliptical shape in the far field in the XY plane with the Y direction as the major axis and the X direction as the minor axis.

[0094] The semiconductor laser element 22 can emit violet, blue, green or red laser light in the visible region, or infrared or ultraviolet laser light in the invisible region. The emission peak wavelength of the violet light is preferably in the range of 400 nm to 420 nm, more preferably in the range of 400 nm to 415 nm. The emission peak wavelength of the blue light is preferably in the range of more than 420 nm to 495 nm, more preferably in the range of 440 nm to 475 nm. The emission peak wavelength of the green light is preferably in the range of more than 495 nm to 570 nm, more preferably in the range of 510 nm to 550 nm. The emission peak wavelength of the red light is preferably in the range of 605 nm to 750 nm, more preferably in the range of 610 nm to 700 nm.

[0095] The semiconductor laser element 22 that emits violet, blue, and green laser light includes a laser diode containing a nitride semiconductor material. Examples of the nitride semiconductor material that can be used include GaN, InGaN, and AlGaN. The semiconductor laser element 22 that emits red laser light includes a laser diode containing an InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductor material.

[0096] As shown in FIG. 4A, the lens support member 23 is supported by the upper surface 21us of the submount 21. The lens support member 23 has two columnar parts 23a and a connecting part 23b located between the two columnar parts 23a and connecting the two columnar parts 23a. The two columnar parts 23a are located on both sides of the semiconductor laser element 22, and the connecting part 23b is located above the emission surface 22e side of the semiconductor laser element 22. The lens support member 23 supports the fast axis collimating lens 24 by the end faces 23as of the two columnar parts 23a. The lens support member 23 is located so as to straddle the semiconductor laser element 22, and does not prevent the laser light emitted from the semiconductor laser element 22 from entering the fast axis collimating lens 24.

[0097] The lens support member 23 may be formed of the above-mentioned ceramics, for example, in the same manner as the support base 60 shown in Figures 1A and 1B. The lens support member 23 may be formed of the above-mentioned light-transmitting material, for example, in the same manner as the condenser lens 70 shown in Figures 1A and 1B. The lens support member 23 may be formed of at least one alloy selected from the group consisting of Kovar and CuW, for example. The lens support member 23 may be formed of Si, for example.

[0098] As shown in FIG. 4A, the fast axis collimating lens 24 may be, for example, a cylindrical lens having a uniform cross-sectional shape in the X direction. The fast axis collimating lens 24 has a flat surface on the light incident side and a convex curved surface on the light exit side. The convex curved surface has a curvature in the YZ plane. The focal point of the fast axis collimating lens 24 approximately coincides with the center of the light emitting point of the exit surface 22e of the semiconductor laser element 22. As shown in FIG. 4B, the fast axis collimating lens 24 collimates the laser light emitted in the +Z direction from the exit surface 22e of the semiconductor laser element 22 in the YZ plane. The region surrounded by the dashed line shown in FIG. 4B is a region where the intensity of the laser light is 1 / e of its peak intensity. 2 represents an area where the axial length is equal to or greater than 100 nm, where e is the base of the natural logarithm. The fast axis collimating lens 24 may be formed of the aforementioned optically transparent material, for example, similar to the focusing lens 70 shown in FIGS. 1A and 1B.

[0099] As shown in Fig. 2F, the fast axis collimating lens 24 is located between the mounting surface 10us of the substrate 10 and the lower surface 50Ls of the cover 50, and is located on the optical path of the laser light L. Since the fast axis collimating lens 24 is disposed inside the sealed space formed by the substrate 10, the frame 40, and the cover 50, the laser light L can be collimated before it spreads too much. Therefore, the fast axis collimating lens 24 can be made compact.

[0100] A collimating lens that collimates the laser light L emitted from the semiconductor laser element 22 not only in the YZ plane but also in the XZ plane may be used instead of the fast axis collimating lens 24. In that case, it is not necessary to provide the slow axis collimating lenses 92, 92a, and 92b in the light-emitting module 200 shown in Figures 1A to 1C and the light-emitting module 210 shown in Figure 1D.

[0101] The present disclosure includes light emitting devices as described in the following items. [Item 1] A substrate having a mounting surface; a semiconductor laser element supported by the mounting surface; a first mirror member supported by the mounting surface and tilted relative to the mounting surface; a first mirror member having a first reflecting surface facing obliquely upward; The substrate has an opposing surface facing the mounting surface and an upper surface located on the opposite side of the opposing surface. a cover located above the semiconductor laser element and the first mirror member; a second mirror member supported by the top surface of the cover, the second mirror member having a second reflective surface, at least a portion of the second reflective surface being located above at least a portion of the first reflective surface; Equipped with the semiconductor laser element is disposed so as to emit a laser beam toward the first reflecting surface, the first reflecting surface reflects the laser light to change a traveling direction of the laser light in a direction away from the mounting surface of the board; the cover transmits the laser light reflected by the first reflecting surface, The second reflecting surface reflects the laser light reflected by the first reflecting surface to further change the traveling direction of the laser light. [Item 2] Item 2. The light emitting device according to item 1, wherein a resin layer is present between a lower surface of the second mirror member and the upper surface of the cover. [Item 3] 3. The light emitting device according to claim 1, wherein the cover has a light-shielding film at least around a region of the facing surface of the cover through which the laser light passes. [Item 4] 4. The laser diode according to claim 1, further comprising a fast axis collimator lens located between the mounting surface of the substrate and the opposing surface of the cover and on an optical path of the laser light. Light emitting device. [Item 5] 5. The light emitting device according to any one of items 1 to 4, wherein the substrate is formed from a material having a thermal conductivity of 10 W / m·K or more and 2000 W / m·K or less. [Item 6] a frame body that is located around the mounting surface of the board and supports the cover, 6. The light emitting device according to any one of items 1 to 5, wherein the semiconductor laser element is hermetically sealed by the substrate, the frame, and the cover. [Industrial Applicability]

[0102] The light emitting device of the present disclosure can be used to combine multiple laser beams to achieve high-power laser beams, and can be used in industrial fields where a high-power laser source is required, such as cutting, drilling, local heat treatment, surface treatment, metal welding, and 3D printing of various materials. [Explanation of symbols]

[0103] 10: Substrate 10us: Mounting surface 10Ls: Bottom surface 20: Laser light source 21: Submount 21Ls: Bottom surface 21us: Top surface 22: Semiconductor laser element 22e: Emission surface 23: Lens support member 23a: Columnar portion 23as: End surface 23b: Connection portion 24: Fast axis collimating lens 30a: First mirror member 30as: First reflecting surface 30b: Second mirror member 30bs: Second reflecting surface 32: Resin layer 40: Frame body 40us1: First top surface 40us2: Second top surface 40Ls1: First bottom surface 40Ls2: Second bottom surface 40p: Protrusion 40w: Wire 42a: First conductive region 42b: Second conductive region 42c: Third conductive region 42d: Fourth conductive region 44a: first bonding region 44b: second bonding region 44c: third bonding region 46: outer region 50: cover 50us: upper surface 50Ls: lower surface 50t: light-transmitting region 52: light-shielding film 60, 62: supporting base 60-1, 62-1: first portion 60-2, 62-2: second portion 60-3, 62-3: third portion 60s1: first mounting surface 60s2: second mounting surface 60s3: third mounting surface 70: focusing lens 70a: fast axis focusing lens 70b: slow axis focusing lens 80: optical fiber 80a: light input end 80b: light output end 82: supporting member 92: slow axis collimating lens 92a: slow axis collimating lens 92b: slow axis collimating lens 94, 94a, 94b, 94c: mirror members 94s, 94as, 94bs, 94cs: reflecting surfaces 96: 1 / 2 wavelength plate 98: polarizing beam splitter 100, 100-1, 100-2: light emitting device 200, 210: light emitting module 230: optical multiplexer 250: optical transmission fiber 300: processing head 400: target object 1000: DDL device

Claims

1. a substrate having a mounting surface; a submount supported by the mounting surface; a semiconductor laser element supported by the submount; a first mirror member supported by the mounting surface; a fast-axis collimating lens positioned between the semiconductor laser element and the first mirror member; a cover positioned above the semiconductor laser element and the first mirror member; a frame positioned around the mounting surface and supporting the cover on its upper surface; comprising a light-emitting device, wherein the cover has a light-transmitting region and a light-shielding region, and a light-shielding film is provided in the light-shielding region.

2. The frame has a first conductive region and a second conductive region on the upper surface, and the first conductive region and the second conductive region are electrically connected to the semiconductor laser element. The light-emitting device according to Claim 1.

3. The frame is joined to the light-shielding film provided on the cover via an inorganic joining member. The light-emitting device according to Claim 1 or 2.

4. Having a second mirror member supported by the upper surface of the cover. The light-emitting device according to any one of Claims 1 to 3.

5. The frame has a protruding portion protruding inward from the inner surface. The light-emitting device according to any one of Claims 1 to 4.

6. The protruding portion protrudes toward both side surfaces of the submount. The light-emitting device according to Claim 5.

7. The upper surface of the protruding portion has a third conductive region, and the third conductive region is electrically connected to the semiconductor laser element via the upper surface of the submount and a wire. The light-emitting device according to Claim 5 or 6.

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