Light emitting device and light emitting module

Abstract

A light emitting device according to the present invention includes: a base having a mounting surface; a plurality of semiconductor laser elements each emitting a laser beam in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of first mirror members each having a first reflecting surface that reflects the laser beam emitted from the corresponding semiconductor laser element and changing the traveling direction of the laser beam in a direction away from the mounting surface; a cover body that transmits the laser beams reflected by the first reflecting surfaces; and one or more second mirror members arranged on the cover body, having second reflecting surfaces that reflect the laser beams transmitted through the cover body, and further changing the traveling direction of the laser beams. The plurality of first mirror members are arranged on the mounting surface such that positions of the first reflecting surfaces in the first direction are different from one another. With the mounting surface serving as a reference surface, the heights of the optical axes of the laser beams reflected by the second reflecting surfaces from the reference surface are different from one another.

Description

Light-emitting device and light-emitting module

[0001] The present disclosure relates to a light emitting device and a light emitting module.

[0002] In recent years, a technology has been developed for increasing the output of laser light by combining multiple laser beams emitted from multiple semiconductor laser elements. Patent Document 1 discloses an example of a laser system that realizes such high-output laser light.

[0003] Special table 2018-530768 publication

[0004] In a light emitting device including a plurality of semiconductor laser elements, it is required to effectively dissipate heat generated from the plurality of semiconductor laser elements during operation to the outside of the light emitting device.

[0005] In one embodiment, the light emitting device according to the present disclosure includes: a base having a mounting surface; a plurality of semiconductor laser elements each having an emission surface for emitting laser light in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of first mirror members each having a first reflection surface for reflecting the laser light emitted from a corresponding semiconductor laser element among the plurality of semiconductor laser elements and changing the traveling direction of the laser light in a direction away from the mounting surface; and a plurality of first mirror members each having an opposing surface facing the mounting surface and an upper surface located on the opposite side of the opposing surface, a lid located above the laser element and the plurality of first mirror members, which transmits the laser light reflected by the first reflecting surface; and one or more second mirror members located on the upper surface of the lid, which have a second reflecting surface that reflects the laser light that has transmitted through the lid, and which further change the traveling direction of the laser light, wherein the plurality of first mirror members are arranged on the mounting surface such that the positions of the first reflecting surfaces in the first direction are different from one another, and the mounting surface is used as a reference plane, and the heights of the optical axes of the laser light reflected by the second reflecting device from the reference plane are different from one another.

[0006] In one embodiment, the light-emitting module of the present disclosure includes the light-emitting device; a plurality of fifth mirror members, each having a fifth reflecting surface that reflects the laser light emitted from a corresponding semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order, in a third direction; and a focusing lens that couples the plurality of laser light beams obtained when the laser light emitted from each of the plurality of semiconductor laser elements is reflected by the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order, into an optical fiber.

[0007] Another light emitting device of the present disclosure, in one embodiment, includes a base having a mounting surface; a plurality of first semiconductor laser elements, each having a first emission surface that emits a first laser light in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of second semiconductor laser elements, each having a second emission surface that emits a second laser light in the first direction and arranged on the mounting surface along the second direction; and first reflectors, each reflecting the first laser light emitted from a corresponding first semiconductor laser element among the plurality of first semiconductor laser elements. a plurality of first mirror members each having a third reflecting surface that reflects the second laser light emitted from a corresponding one of the plurality of second semiconductor laser elements and changing the traveling direction of the second laser light in a direction away from the mounting surface; and a plurality of third mirror members each having an opposing surface that faces the mounting surface and an upper surface located on the opposite side to the opposing surface, and a lid member located above the plurality of third mirror members and transmitting the first laser light reflected by the first reflecting surface and the second laser light reflected by the third reflecting surface; a second mirror member located on the upper surface of the lid member and having a second reflecting surface that reflects the first laser light that has passed through the lid member and further changing the traveling direction of the first laser light; and a fourth mirror member located on the upper surface of the lid member in a direction opposite to the first direction relative to the second mirror member and having a fourth reflecting surface that reflects the second laser light that has passed through the lid member and further changing the traveling direction of the second laser light, wherein the plurality of second semiconductor laser elements are located in a direction opposite to the first direction relative to the plurality of first semiconductor laser elements, the plurality of first mirror members are located on the mounting surface such that positions of the first reflecting surfaces in the first direction are different from one another, and the plurality of third mirror members are located on the mounting surface such that positions of the third reflecting surfaces in the first direction are different from one another and in a direction opposite to the first direction relative to the plurality of first mirror members.

[0008] Another light-emitting module of the present disclosure, in one embodiment, includes the other light-emitting device; a plurality of fifth mirror members each having a fifth reflecting surface that reflects, in a third direction, the first laser light emitted from a corresponding first semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order; a plurality of sixth mirror members each having a sixth reflecting surface that reflects, in the third direction, the second laser light emitted from a corresponding second semiconductor laser element and reflected by the third reflecting surface and the fourth reflecting surface in this order; and a focusing lens that couples, into an optical fiber, a plurality of first laser light beams obtained by the first laser light emitted from each of the plurality of first semiconductor laser elements being reflected by the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order, and a plurality of second laser light beams obtained by the second laser light emitted from each of the plurality of second semiconductor laser elements being reflected by the third reflecting surface, the fourth reflecting surface, and the sixth reflecting surface in this order.

[0009] According to the embodiments of the present disclosure, in a light emitting device including a plurality of semiconductor laser elements, heat generated from the plurality of semiconductor laser elements during operation can be effectively dissipated to the outside of the light emitting device.

[0010] FIG. 1A is a perspective view schematically illustrating a configuration of a light-emitting device according to a first exemplary embodiment of the present disclosure. FIG. 1B is an exploded perspective view of the light-emitting device shown in FIG. 1A. FIG. 1C is a top view of the light-emitting device shown in FIG. 1A , with a lid, a second mirror member, and a slow-axis collimating lens array omitted. FIG. 1D is a cross-sectional view parallel to the YZ plane of the light-emitting device shown in FIG. 1A. FIG. 2A is a perspective view schematically illustrating a configuration of a first modified example of the light-emitting device according to the first exemplary embodiment of the present disclosure. FIG. 2B is an exploded perspective view schematically illustrating a configuration of a second modified example of the light-emitting device according to the first exemplary embodiment of the present disclosure. FIG. 3A is a top view schematically illustrating a configuration of a light-emitting module according to the first exemplary embodiment of the present disclosure. FIG. 3B is a side view schematically illustrating a configuration of a light-emitting module according to the first exemplary embodiment of the present disclosure. FIG. 3C is another side view schematically illustrating a configuration of a light-emitting module according to the first exemplary embodiment of the present disclosure. FIG. 4A is a perspective view schematically illustrating a configuration of a light-emitting device according to a second exemplary embodiment of the present disclosure. FIG. 4B is an exploded perspective view of the light-emitting device shown in FIG. 4A. Fig. 4C is a top view of a configuration in which the lid and components on the lid are omitted from the light emitting device shown in Fig. 4B. Fig. 4D is a cross-sectional view parallel to the YZ plane of the light emitting device shown in Fig. 4A. Fig. 5A is a top view schematically showing a configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. Fig. 5B is a side view schematically showing a configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. Fig. 5C is another side view schematically showing the configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. Fig. 6A is an exploded perspective view of a laser light source. Fig. 6B is a cross-sectional view parallel to the YZ plane of the laser light source.

[0011] Hereinafter, a light emitting device and a light emitting module according to an embodiment of the present disclosure will be described with reference to the drawings. The light emitting module includes a plurality of light emitting devices. Parts that appear in multiple drawings with the same reference numerals indicate the same or equivalent parts.

[0012] Furthermore, the embodiments described below are examples to embody the technical idea of ​​the present invention, and do not limit the present invention. Furthermore, the size, material, shape, relative arrangement, etc. of components are intended to be illustrative and not to limit the scope of the present invention. The size and positional relationship of components shown in each drawing may be exaggerated to facilitate understanding.

[0013] In this specification and claims, polygons such as triangles and quadrilaterals are referred to as polygons, including shapes in which the corners of the polygon have been rounded, chamfered, corner-cut, or rounded. Shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while retaining the polygonal base are included in the interpretation of "polygon" described in this specification and claims.

[0014] (Embodiment 1) [Light-Emitting Device] First, with reference to FIGS. 1A to 1D, a configuration example of a light-emitting device according to embodiment 1 of the present disclosure will be described. FIG. 1A is a perspective view schematically illustrating the configuration of a light-emitting device according to exemplary embodiment 1 of the present disclosure. The light-emitting device 100A shown in FIG. 1A can be placed on, for example, a mounting surface of a supporting base. Details of the supporting base will be described later in the description of the light-emitting module according to embodiment 1. FIG. 1B is an exploded perspective view of the light-emitting device shown in FIG. 1A. The light-emitting device 100A shown in FIG. 1B includes a base 10A, a plurality of laser light sources 20, a plurality of first mirror members 30a, a second mirror member 30b, a cover 40A, and a slow-axis collimating lens array 50. The slow-axis collimating lens array 50 is integrally formed and includes a plurality of slow-axis collimating lenses 50s, each of which functions as a lens.

[0015] The base 10A has a mounting surface 10s. Each first mirror member 30a has a first reflecting surface 30as, and each second mirror member 30b has a second reflecting surface 30bs. The cover 40A has an upper surface 42 and a lower surface 44. The laser light source 20 is a chip-on-submount type semiconductor laser light source having a semiconductor laser element. In the example shown in FIG. 1B, the number of laser light sources 20 is three, but this number is not limited to three. The number of laser light sources 20 may be two, four, or more. It is preferable that the number of first mirror members 30a and slow-axis collimating lenses 50s be the same as the number of laser light sources 20. The light-emitting device 100A may further include a protection element such as a Zener diode and / or a temperature measurement element such as a thermistor for measuring the internal temperature.

[0016] In these figures, for reference, the mutually orthogonal X-axis, Y-axis, and Z-axis are schematically shown. The direction of the X-axis arrow is referred to as the +X direction, and the opposite direction is referred to as the -X direction. When there is no distinction between the ±X directions, they are simply referred to as the X direction. The same applies to the Y and Z directions. In this specification, for ease of explanation, the +Y direction is referred to as "upward" and the -Y direction is referred to as "downward." This does not limit the orientation of the light-emitting device when in use, and the orientation of the light-emitting device is arbitrary.

[0017] Fig. 1C is a top view of the light emitting device 100A shown in Fig. 1A , omitting the lid 40A, the second mirror member 30b, and the slow-axis collimating lens array 50. Fig. 1D is a cross-sectional view of the light emitting device 100A shown in Fig. 1A , taken parallel to the YZ plane.

[0018] As will be explained in detail later, in the light-emitting device 100A according to the first embodiment, as shown in FIG. 1D , the plurality of laser light sources 20 and the plurality of first mirror members 30a are arranged on the mounting surface 10s, and the laser light L emitted from each of the plurality of laser light sources 20 is reflected in this order by the first reflecting surface 30as and the second reflecting surface 30bs and travels in the +Z direction. As shown in FIG. 1C , the plurality of first mirror members 30a are arranged on the mounting surface 10s so that the positions of the first reflecting surfaces 30as in the Z direction are different from each other. Therefore, even if the mounting surface 10s on which the plurality of laser light sources 20 are mounted is the same plane, the heights of the optical axes of the plurality of laser light beams L can be made different from each other using the mounting surface 10s as a reference plane for height. This is because the distance between the point on the first reflecting surface 30as where the optical axis of the laser light L strikes and the point on the second reflecting surface 30bs where the optical axis of the laser light L strikes depends on the position of the first reflecting surface 30as in the Z direction. The laser light L emitted from the laser light source 20 is a beam collimated in the YZ plane, and its optical axis passes through the center of the beam cross section.

[0019] Furthermore, by arranging the multiple first mirror members 30a on the mounting surface so that the positions of the first reflecting surfaces 30as in the first direction are different from one another, multiple collimated beams of different heights can be obtained. This allows the mounting surface 10s to be flush. Because multiple collimated beams of different heights can be obtained without providing steps on the mounting surface 10s, the variation in the distance between the mounting surface 10s and the lower surface 14 (described later) can be reduced. This reduces the variation in the amount of heat generated by the multiple laser light sources 20 during operation and transmitted to the mounting surface of the support base. Therefore, the heat generated by the multiple laser light sources 20 during operation can be effectively dissipated to the outside of the light-emitting device 100A. For example, if the support base has a flow path extending along the X direction below the mounting surface, flowing a liquid through the flow path can reduce the variation in the degree of cooling of the multiple laser light sources 20 within the light-emitting device 100A. Furthermore, when the support base is provided with a heat sink below the mounting surface, it is possible to reduce the variation in the degree of heat dissipation of the multiple laser light sources 20 in the light emitting device 100A. If the distance between the mounting surface 10s and the lower surface 14 directly below the multiple laser light sources 20 is constant, it is possible to further reduce the variation in heat dissipation and perform heat dissipation more effectively.

[0020] Each component of the light emitting device 100A will be described below.

[0021] <Base 10A> As shown in FIG. 1B , the base 10A includes a flat plate portion having a mounting surface 10s on which the plurality of laser light sources 20 and the plurality of first mirror members 30a are mounted, and a sidewall portion positioned around the mounting surface 10s and surrounding the plurality of laser light sources 20 and the plurality of first mirror members 30a. The base 10A accommodates the plurality of laser light sources 20 and the plurality of first mirror members 30a. In the example shown in FIG. 1B , the mounting surface 10s is parallel to the XZ plane. The flat plate portion and the sidewall portion may be integrally formed or may be formed separately and then joined together. In the example shown in FIG. 1B , the flat plate portion has a rectangular flat plate shape, but this shape is not limited thereto. The flat plate portion may have, for example, a polygonal, circular, or elliptical flat plate shape. The base 10A generally has a box shape with an open top.

[0022] The base 10A has a first upper surface 12a and a second upper surface 12b corresponding to the upper surfaces of the sidewall portions. The first upper surface 12a and the second upper surface 12b surround the multiple laser light sources 20 and the multiple first mirror members 30a in a top view seen from the normal direction of the mounting surface 10s. The second upper surface 12b is located above the first upper surface 12a and surrounds the first upper surface 12a in a top view. The base 10A further has a lower surface 14 corresponding to the lower surface of the flat portion. The normal direction of the mounting surface 10s is the +Y direction. In this specification, the normal direction of a surface means the direction perpendicular to the surface, that is, the direction away from the object having the surface.

[0023] The first upper surface 12a of the base 10A is bonded to a peripheral region of the lower surface 44 of the lid 40A. A metal film 16 is provided on the first upper surface 12a, and the base 10A and the lid 40A are bonded together by, for example, an inorganic bonding member provided on the metal film 16. The metal film 16 may be formed of at least one metal material selected from the group consisting of, for example, Ag, Cu, W, Au, Ni, Pt, Sn, Ti, and Pd.

[0024] The base 10A has internal wiring for supplying power to each laser light source 20. Each laser light source 20 is electrically connected to an external circuit via the internal wiring, and the external circuit supplies power to the multiple laser light sources 20 simultaneously or at different times.

[0025] The base 10A includes a region formed from a material with high thermal conductivity. The thermal conductivity of the material may be, for example, 10 W / m·K or more and 2000 W / m·K or less. The base 10A with such high thermal conductivity allows heat generated by the laser light source 20 during operation to be effectively conducted to the support substrate via the base 10A. The base 10A may be formed from a ceramic selected from the group consisting of AlN, SiN, SiC, and alumina. The dimension of the base 10A in the X direction may be, for example, 7 mm or more and 45 mm or less, the dimension in the Y direction may be, for example, 2 mm or more and 3 mm or less, and the dimension in the Z direction may be, for example, 15 mm or more and 25 mm or less.

[0026] <Laser Light Sources 20> As shown in FIG. 1B, the multiple laser light sources 20 are arranged on the mounting surface 10s. As shown in FIG. 1C, the multiple laser light sources 20 are arranged along the X direction such that the positions of the multiple laser light sources 20 in the Z direction differ from one another. In the example shown in FIG. 1C, the multiple laser light sources 20 are arranged so as to be shifted stepwise in the −Z direction along the X direction. The shift direction may not be the −Z direction, but the opposite direction, the +Z direction. Alternatively, the positions of the multiple laser light sources 20 in the Z direction may be irregular along the X direction.

[0027] When the mounting surface 10s is flush with one another, it is possible to reduce variations in the amount of heat emitted from the multiple laser light sources 20 during operation and transferred to the mounting surface of the support base, thereby effectively transferring the heat emitted from the multiple laser light sources 20 during operation to the outside of the light emitting device 100A.

[0028] 1B , each laser light source 20 includes a submount 21, an edge-emitting 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 10s via the submount 21. The semiconductor laser element 22 is disposed so as to emit laser light 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 face.

[0029] The components of the laser light source 20 may be treated as components of the light-emitting device 100A. That is, the light-emitting device 100A includes a plurality of submounts 21, a plurality of semiconductor laser elements 22, a plurality of lens support members 23, and a plurality of fast-axis collimating lenses 24. These components are located between the mounting surface 10s of the base 10A and the lower surface 44 of the lid 40A. The plurality of semiconductor laser elements 22 are indirectly disposed on the mounting surface 10s along the X direction. More specifically, each semiconductor laser element 22 is disposed on the mounting surface 10s via a corresponding submount 21. The plurality of semiconductor laser elements 22 may also be disposed directly on the mounting surface 10s along the X direction.

[0030] The semiconductor laser element 22 has an emission surface from which laser light L is emitted in the +Z direction. 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 quickly in the YZ plane and spreads relatively slowly 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.

[0031] The laser light source 20 emits laser light L that is emitted from a semiconductor laser element 22 and transmitted through a fast-axis collimating lens 24. The fast-axis collimating lens 24 collimates the laser light L emitted from the semiconductor laser element 22 in the YZ plane, more specifically, in the fast-axis direction within the YZ plane. Therefore, the laser light L emitted from the laser light source 20 is collimated in the YZ plane but not in the XZ plane. In this specification, "collimating" means not only converting the laser light L into parallel light but also reducing the divergence angle of the laser light L. The wavelengths of the laser light L emitted from the multiple laser light sources 20 may be equal to or different from each other. Alternatively, the wavelengths of the laser light L emitted from some of the laser light sources 20 may be different from the wavelengths of the laser light L emitted from the remaining laser light sources 20. A specific configuration of the laser light source 20 will be described later.

[0032] As shown in FIG. 1D , the laser light source 20 is sealed by a base 10A and a lid 40A. This sealing is preferably airtight. Airtight sealing reduces dust collection on the emission surface of the semiconductor laser element 22, making the semiconductor laser element 22 less likely to malfunction. 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 where the emission surface of the semiconductor laser element 22 is not airtight sealed and is exposed to the outside air, the shorter the wavelength of the laser light, the more likely it is that the emission surface will deteriorate during operation due to dust collection.

[0033] It should be noted that 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 arranged so that the laser light emitted from the semiconductor laser element travels in the +Z direction.

[0034] <First Mirror Member 30a and Second Mirror Member 30b> As shown in FIG. 1B, the multiple first mirror members 30a are arranged on the mounting surface 10s of the base 10A. As shown in FIG. 1C, the multiple first mirror members 30a are arranged along the X direction so that the positions of their first reflecting surfaces 30as in the Z direction differ from one another. In the example shown in FIG. 1C, the multiple first mirror members 30a are arranged so as to be shifted stepwise in the −Z direction along the X direction, similar to the multiple laser light sources 20. The shift direction may not be the −Z direction, but the opposite direction, the +Z direction. Alternatively, the positions of the multiple first mirror members 30a in the Z direction may be irregular along the X direction.

[0035] 1C , the distances defined by the distances between each of the plurality of first mirror members 30a and a corresponding one of the plurality of laser light sources 20 are substantially the same. The distance is the distance between the point on the first reflecting surface 30as of each first mirror member 30a where the optical axis of the laser light L strikes and the center of the emission surface of the semiconductor laser element 22 included in the corresponding laser light source 20. With such a configuration, the beam diameters of the laser light reflected by the first mirror member 30a and the second mirror member 30b are the same for all laser light, simplifying the optical design in the subsequent stages.

[0036] 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. In this specification, the angle between two directions has a positive value and does not have a negative value. In the example shown in FIG. 1D, 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°.

[0037] The first mirror member 30a has a first reflecting surface 30as. The first reflecting surface 30as is inclined with respect to the mounting surface 10s of the base 10A and faces obliquely upward. In this specification, "obliquely upward" means a direction that forms an angle of 30° to 60° with the +Y direction.

[0038] 1D , each first mirror member 30a, more specifically, its first reflecting surface 30as, reflects the laser light L emitted from the corresponding laser light source 20, changing the traveling direction of the laser light L in a direction away from the mounting surface 10s of the base 10A. The angle formed between the traveling direction of the laser light L away from the mounting surface 10s of the base 10A and the normal direction of the mounting surface 10s can be, for example, greater than or equal to 0° and less than or equal to 5°.

[0039] As shown in FIG. 1A , the second mirror member 30b is disposed on the upper surface 42 of the cover 40A. The second mirror member 30b has a shape extending along the X direction. The second mirror member 30b further has a uniform cross-sectional shape in the X direction. This cross-sectional shape is roughly trapezoidal. The second mirror member 30b has an upper surface, a lower surface, a back surface, and a slope connecting the upper and lower surfaces. Each of the upper and lower surfaces 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. Meanwhile, 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 parallel to the YZ plane and forms an acute angle with the −Y direction and an acute angle with the +Z direction. In the example shown in FIG. 1D , 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, between 30° and 60°. The angle formed between the upper surface and the inclined surface of the second mirror member 30b may be equal to or different from the angle formed between the lower surface and the inclined surface of the first mirror member 30a.

[0040] The second mirror member 30b has a second reflecting surface 30bs. A portion of the second reflecting surface 30bs is located above at least a portion of the first reflecting surface 30as of each first mirror member 30a. As shown in FIG. 1D , the second mirror member 30b, more specifically its second reflecting surface 30bs, reflects the laser light L that has been reflected by the first reflecting surface 30as and transmitted through the cover body 40A, thereby further changing the traveling direction of the laser light L in the +Z direction. Unlike the multiple first mirror members 30a, the second mirror member 30b may be a single member. By using a single member for the second mirror member 30b, misalignment of the optical axis due to misalignment of the members can be reduced.

[0041] Since the positions of the multiple first mirror members 30a in the Z direction are different from one another, the heights of the optical axes of the multiple laser beams L reflected by the second reflecting surface 30bs are different from one another, with the mounting surface 10s being used as the reference plane for height. This is because the distance between the point on the first reflecting surface 30as where the optical axis of the laser beam L hits and the point on the second reflecting surface 30bs where the optical axis of the laser beam L hits depends on the position of the first reflecting surface 30as in the Z direction.

[0042] 1D , the first mirror members 30a are arranged so as to be shifted in the −Z direction in stages along the X direction, so that the heights of the optical axes of the laser beams L reflected by the second reflecting surface 30bs decrease in stages along the +X direction. The absolute value of the difference in the heights of the optical axes of two adjacent laser beams L among the laser beams L is, for example, 0.3 mm or more and 0.5 mm or less.

[0043] As shown in FIG. 1D , a resin layer 32 is present between the lower surface of the second mirror member 30b and the upper surface 42 of the lid body 40A. The resin layer 32 is formed by curing the resin while the lower surface of the second mirror member 30b is in contact with the upper surface 42 of the lid body 40A via the uncured resin. 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 or visible light. The following active alignment may be performed before the resin is cured. That is, with the laser light sources 20 emitting 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 propagation direction of the multiple laser light beams L in the +Z direction.

[0044] 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. 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 up and down. By rotating the second mirror member 30b about the Y-axis as a rotation axis, the traveling direction of the laser light L can be changed left and right, with the traveling direction of the laser light L being the front direction.

[0045] Furthermore, by adjusting the position of the second mirror member 30b in the Z direction, it is possible to adjust the height of the optical axis of the laser light L. By shifting the second mirror member 30b along the +Z direction, it is possible to reduce the height of the optical axis of the laser light L, and by shifting the second mirror member 30b along the −Z direction, it is possible to increase the height of the optical axis of the laser light L.

[0046] The first mirror member 30a and the second mirror member 30b are, for example, inclined bases having reflective surfaces. The bases may be made of at least one material selected from the group consisting of glass, quartz, synthetic quartz, sapphire, ceramics, silicon, metal, and dielectric materials. The reflective surfaces may be made of reflective materials such as dielectric multilayer films and metal materials. These reflective surfaces correspond to the first reflective surface 30as and the second reflective surface 30bs.

[0047] Alternatively, the first mirror member 30a and the second mirror member 30b may each have a base with a slope, and the base may be made of the above-mentioned reflective material. In this case, the slope of the base corresponds to the first reflecting surface 30as and the second reflecting surface 30bs.

[0048] <Cover 40A> As shown in FIG. 1B , the cover 40A has an upper surface 42 and a lower surface 44. The lower surface 44 of the cover 40A faces the mounting surface 10s of the base 10A, and the upper surface 42 of the cover 40A is located opposite the lower surface 44 of the cover 40A. In this specification, the lower surface 44 of the cover 40A is also referred to as the "facing surface." The cover 40A is located above the plurality of semiconductor laser elements 22 and the plurality of first mirror members 30a. The cover 40A transmits the laser light L reflected by the first reflecting surface 30as of each first mirror member 30a. More specifically, the cover 40A has a plurality of light-transmitting portions 46, and each light-transmitting portion 46 transmits the laser light L reflected by the first reflecting surface 30as of the corresponding first mirror member 30a.

[0049] The cover 40A may have a light-shielding film 48 at least around the periphery of each of the plurality of light-transmitting portions 46 on the lower surface 44. In the example shown in Fig. 1B, the lower surface of the light-transmitting portion 46 has a rectangular shape, but is not limited to this shape. The shape of the lower surface of the light-transmitting portion 46 may be, for example, circular or elliptical.

[0050] The light-shielding film 48 reduces the possibility that stray light other than the laser light L generated inside the light-emitting device 100A will leak to the outside of the light-emitting device 100A. This effect reduces the possibility that stray light other than the laser light L generated inside the light-emitting device 100A will reach the resin layer 32 shown in FIG. 1D , thereby effectively reducing deterioration of the resin layer 32. The light-shielding film 48 also reduces the possibility that ultraviolet light or visible light will reach the laser light source 20 when the resin layer 32 is formed by irradiation with ultraviolet light or visible light. The light-shielding film 48 also reduces the possibility that return light of the laser light L emitted to the outside of the light-emitting device 100A will reach the laser light source 20. Reducing irradiation by ultraviolet light or visible light or return light makes the laser light source 20 less susceptible to damage.

[0051] 1B , the light-shielding film 48 is provided on the entire area of ​​the lower surface 44 except for the lower surfaces of the plurality of light-transmitting portions 46. The light-shielding film 48 thus provided further reduces the possibility that the stray light will leak to the outside of the light-emitting device 100A and that the ultraviolet light or visible light or the returned light will reach the laser light source 20. However, the light-shielding film 48 does not necessarily have to be provided on the lower surface 44 of the lid 40A.

[0052] In the lid body 40A, a light-transmitting portion 46 that transmits the laser light L may have a transmittance of, for example, 60% or more, and preferably 80% or more, for the laser light L. The remaining portions of the lid body 40A may or may not have such light-transmitting properties.

[0053] The lid 40A may be made of at least one light-transmitting material selected from the group consisting of glass, silicon, quartz, synthetic quartz, sapphire, and transparent ceramics. The lid 40A may have a dimension in the X direction of 6 mm to 44 mm, a dimension in the Y direction of 0.1 mm to 1.5 mm, and a dimension in the Z direction of 10 mm to 20 mm.

[0054] The light-shielding film 48 may be formed from a metal material such as Ag, Cu, W, Au, Ni, Pt, Sn, Ti, or Pd. The light-shielding film 48 may be formed, for example, by photolithography. Alternatively, the light-shielding film 48 may be formed, for example, by providing a metal film on the entire lower surface 44 of the lid 40A and patterning the metal film by etching.

[0055] The peripheral region of the light-shielding film 48 is bonded to the metal film 16 provided on the first upper surface 12a of the base 10A via an inorganic bonding member such as a solder material. When the light-shielding film 48 is formed from the same metal material as the metal film 16, the base 10A and the lid 40A are bonded together by, for example, an inorganic bonding member provided on the light-shielding film 48. Note that the metal film 16 may be provided separately from the light-shielding film 48 on the lower surface 44 of the lid 40A.

[0056] 1A to 1C, the lid 40A has a flat plate shape, but is not limited to this shape. The base 10A may have a flat plate shape, and the lid 40A may have a box shape with an open bottom. In such a shape, the base 10A and the lid 40A are joined together so that the lower surface of the lid 40A is supported by the peripheral region of the mounting surface 10s of the base 10A. Alternatively, the base 10A may have a box shape with an open top, and the lid 40A may have a box shape with an open bottom. In such a shape, the base 10A and the lid 40A are joined together so that the lower surface of the lid 40A is supported by the upper surface of the base 10A.

[0057] <Slow-axis collimating lens array 50> As shown in FIG. 1A, the slow-axis collimating lens array 50 is disposed on the upper surface 42 of the lid 40A and includes a plurality of slow-axis collimating lenses 50s. In the example shown in FIGS. 1A and 1B, the slow-axis collimating lens array 50 is integrally formed. Since the components are formed integrally, the influence of misalignment when arranging the components can be reduced. Note that the plurality of slow-axis collimating lenses 50s may be separated into individual pieces.

[0058] As shown in FIG. 1D , each of the multiple slow-axis collimating lenses 50s collimates, in the XZ plane, the laser light L emitted from a corresponding one of the multiple laser light sources 20 and reflected by the first reflecting surface 30as and the second reflecting surface 30bs in this order, more specifically, in the slow-axis direction within the XZ plane. Because the slow-axis collimating lens array 50 is disposed on the upper surface 42 of the lid 40A, the laser light L can be collimated before it spreads significantly in the XZ plane. This allows the slow-axis collimating lens array 50 to be made compact. Each slow-axis collimating lens 50s can be formed, for example, from the same light-transmitting material as the lid 40.

[0059] Alternatively, a wedge prism may be provided between the second mirror member 30b and the slow axis collimator lens array 50, so that the laser light L reflected by the second reflecting surface 30bs and directed toward the slow axis collimator lens array 50 passes through the wedge prism. With such a configuration, the optical path of the laser light L incident on each slow axis collimator lens 50s can be corrected.

[0060] From the above, according to the light emitting device 100A of the first embodiment, even if the mounting surface 10s on which the multiple laser light sources 20 are mounted is the same plane, the mounting surface 10s can be used as a reference plane for height to make the heights of the optical axes of the multiple laser light beams L different from one another. Furthermore, when the mounting surface 10s is the same plane, it is possible to reduce the variation in the amount of heat generated from the multiple laser light sources 20 during operation and transferred to the mounting surface of the support base. As a result, it is possible to effectively transfer the heat generated from the multiple laser light sources 20 during operation to the outside of the light emitting device 100A.

[0061] The light-emitting device 100A can be manufactured, for example, as follows. In a first step, a base 10A, a plurality of laser light sources 20, a plurality of first mirror members 30a, a second mirror member 30b, a lid 40A, and a slow-axis collimating lens array 50 are prepared. In a next step, the plurality of laser light sources 20 and the plurality of first mirror members 30a are provided on the mounting surface 10s of the base 10A. In a next step, the lid 40A is bonded to the base 10A. In a next step, active alignment is performed with the lower surface of the second mirror member 30b in contact with the upper surface 42 of the lid 40A via uncured resin. In a next step, the resin is cured to form a resin layer 32 between the second mirror member 30b and the lid 40A. In a next step, the slow-axis collimating lens array 50 is provided on the upper surface 42 of the lid 40A.

[0062] (Modifications of Light Emitting Device 100A) Next, first and second modifications of the light emitting device 100A according to the first embodiment will be described with reference to FIGS. 2A and 2B, respectively.

[0063] FIG. 2A is a perspective view schematically illustrating the configuration of a first modified example of the light-emitting device according to the first embodiment of the present disclosure. The light-emitting device 110A illustrated in FIG. 2A differs from the light-emitting device 100A illustrated in FIG. 1A in that the light-emitting device 110A includes multiple second mirror members 30b instead of a single second mirror member 30b. The number of second mirror members 30b is the same as the number of laser light sources 20. The interior of the light-emitting device 110A is the same as the interior of the light-emitting device 100A illustrated in FIG. 1B. At least a portion of the second reflecting surface 30bs of each second mirror member 30b is located above at least a portion of the first reflecting surface 30as of the corresponding first mirror member 30a. The laser light L emitted from each laser light source 20 is reflected by the first reflecting surface 30as of the corresponding first mirror member 30a and the second reflecting surface 30bs of the corresponding second mirror member 30b, in this order. Since the positions and orientations of the plurality of second mirror members 30b can be adjusted individually, the deviation between the traveling direction of each of the plurality of laser beams L and the +Z direction can be effectively reduced.

[0064] 2B is an exploded perspective view schematically illustrating the configuration of Modification 2 of the light-emitting device according to Embodiment 1 of the present disclosure. Light-emitting device 120A illustrated in FIG. 2B differs from light-emitting device 100A illustrated in FIG. 1A in that light-emitting device 120A includes multiple housings 10h arranged on mounting surface 10s. Each of the multiple housings 10h houses one of the multiple laser light sources 20 and one of the multiple first mirror members 30a corresponding to that one laser light source 20. In this case, the laser light source 20 and the first mirror member 30a are arranged on mounting surface 10s via the housings 10h.

[0065] Because the housing 10h that houses the laser light source 20 and the first mirror member 30a can be treated as a single unit, by arranging multiple units on the mounting surface 10s, multiple laser light sources 20 and multiple first mirror members 30a can be easily housed in the base 10A. Furthermore, by sealing, more preferably hermetically sealing, the laser light source 20 and the first mirror member 30a in the housing 10h, the durability of the laser light source 20 and the first mirror member 30a can be improved.

[0066] The housing 10h transmits the laser light L emitted from the laser light source 20 and reflected by the first reflecting surface 30as of the first mirror member 30a. In Fig. 2B, for ease of understanding, the inside of the housing 10h is shown as transparent, but as long as the light-transmitting portion of the housing 10h that transmits the laser light L has light-transmitting properties, the remaining portion may or may not have light-transmitting properties.

[0067] 3A to 3C, a configuration example of a light-emitting module according to the first embodiment of the present disclosure will be described. The light-emitting module includes the light-emitting device 100A shown in FIG. 1, but the light-emitting device 100A may be used for other purposes without being employed in the light-emitting module.

[0068] Fig. 3A is a top view schematically showing the configuration of a light emitting module according to the first exemplary embodiment of the present disclosure, Fig. 3B is a side view schematically showing the configuration of a light emitting module according to the first exemplary embodiment of the present disclosure, and Fig. 3C is another side view schematically showing the configuration of a light emitting module according to the first exemplary embodiment of the present disclosure.

[0069] 3A to 3C includes a support base 60A, a condenser lens 70, an optical fiber 80, a support member 82 that supports the optical fiber 80, a plurality of mirror members 90, and a light emitting device 100A. Each mirror member 90 has a reflective surface 90s.

[0070] As shown in FIG. 3B , the support base 60A is disposed on a reference plane Ref parallel to the XZ plane. The reference plane Ref is a reference plane for height in the light emitting module 200A. As shown in FIG. 3A , the support base 60A includes a first portion 60A1 that supports the light emitting device 100A. The support base 60A further includes a plurality of second portions 60A2 supported by the first portion 60A1. Each second portion 60A2 supports a corresponding mirror member 90. The support base 60A further includes a third portion 60A3 connected to the first portion 60A1. The third portion 60A3 supports the condenser lens 70 and the optical fiber 80.

[0071] The first portion 60A1 has a first mounting surface 60s1, and a plurality of second portions 60A2 are arranged on the first mounting surface 60s1. Each second portion 60A2 has a second mounting surface 60s2. The third portion 60A3 has a third mounting surface 60s3.

[0072] The first mounting surface 60s1 is a plane parallel to the XZ plane. The heights of the multiple second mounting surfaces 60s2 decrease stepwise along the +X direction, as shown in FIG. 3B . As shown in FIG. 3A , the light emitting device 100A is disposed on the first mounting surface 60s1 in addition to multiple second portions 60A2. The lower surface 14 of the base 10A (shown in FIG. 1B ) included in the light emitting device 100A is bonded to the first mounting surface 60s1 of the support base 60A via an inorganic bonding material such as solder. A metal film may be provided on the lower surface 14 of the base 10A. A corresponding mirror member 90 is disposed on each second mounting surface 60s2. If the mirror member 90 has a sufficiently large dimension in the Y direction, the mirror member 90 may be disposed on the first mounting surface 60s1 without the second portions 60A2. The condenser lens 70 is disposed on the third mounting surface 60s3, and the optical fiber 80 is disposed via a support member 82.

[0073] 3B , the height of the third mounting surface 60s3 from the reference plane Ref is greater than the height of the first mounting surface 60s1 from the reference plane Ref and less than the minimum height of the second mounting surfaces 60s2 from the reference plane Ref. 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 height of the first mounting surface 60s1. Alternatively, the height of the third mounting surface 60s3 may be equal to or greater than the maximum height of the second mounting surfaces 60s2.

[0074] The support base 60A may be formed of a ceramic selected from the group consisting of AlN, SiN, SiC, and alumina. Alternatively, the support base 60A may be formed of at least one metal material selected from the group consisting of Cu, Al, and W. The support base 60A 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 W. The support base 60A may be formed integrally or may be an assembly of multiple parts. The multiple parts may be formed from the same material or different materials. For example, the first portion 60A1, the multiple second portions 60A2, and the third portion 60A3 may be formed integrally or independently. Alternatively, the first portion 60A1 and the third portion 60A3 may be integrally formed, and the plurality of second portions 60A2 may be formed independently of the first portion 60A1 and the third portion 60A3.

[0075] The support base 60A is preferably made of a single metal material selected from the group consisting of Cu, Al, and W. Metal materials have better heat dissipation properties than ceramics, and are soft and therefore easy to process.

[0076] The support base 60A functions as a support base on which the light emitting device 100A is placed. The support base 60A can also function as a heat sink that transfers heat generated by the light emitting device 100A to the outside to reduce excessive temperature rise of the light emitting device 100A. In this case, one or more flow paths for liquid cooling may be provided inside the support base 60A. Water, for example, can be used as the liquid used for liquid cooling. Furthermore, a fin structure for air cooling may be provided on the surface of the support base 60A. Alternatively, when the support base 60A is placed on a separately prepared heat sink, the support base 60A can also function as a heat spreader that transfers heat generated by the light emitting device 100A to the heat sink.

[0077] As shown in Figures 3A and 3C, the light-emitting device 100A emits multiple laser beams L in the +Z direction. In the light-emitting device 100A shown in Figure 1B, each laser beam L is emitted from a corresponding laser light source 20 and reflected by the first reflecting surface 30as and the second reflecting surface 30bs, in that order. Each laser beam L is collimated in the XZ plane and the YZ plane. As shown in Figures 3A and 3B, the reflecting surface 90s of each mirror member 90 reflects the corresponding laser beam L, changing the traveling direction of the laser beam L toward the condenser lens 70 in the +X direction.

[0078] Each laser beam L is represented by a thick line with three arrows in the example shown in Fig. 3A, and by a thick line with one arrow in the examples shown in Fig. 3B and Fig. 3C. In the example shown in Fig. 3A, the laser beam L is represented by a thick line with three arrows in order to emphasize that the laser beam L has a spread.

[0079] The traveling directions of some or all of the multiple laser beams L emitted from light-emitting device 100A may actually deviate from the +Z direction. Even in this case, by appropriately adjusting the position and orientation of mirror member 90 shown in FIG. 3A , it is possible to reduce the deviation between the traveling direction of laser beam L reflected by reflecting surface 90s and the +X direction. The angle between the traveling direction of laser beam L reflected by reflecting surface 90s and the +X direction is preferably, for example, 1° or less, and more preferably 0.1° or less.

[0080] 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 axes of the fast axis condenser lens 70a and the slow axis condenser lens 70b are parallel to the X direction. The condenser lens 70 may be formed from the above-mentioned light-transmitting material, similar to the cover body 40A shown in FIGS. 1A and 1B .

[0081] The fast axis focusing lens 70a is positioned so that its focal point substantially coincides with the light incident end 80a of the optical fiber 80. Similarly, the slow axis focusing lens 70b is positioned so that its focal point substantially 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 the focal length of the slow axis focusing lens 70b. As shown in FIG. 3B , the fast axis focusing lens 70a converges the multiple laser beams L onto the light incident end 80a of the optical fiber 80 in the XY plane. As shown in FIG. 3A , the slow axis focusing lens 70b converges each laser beam L onto the light incident end 80a in the XZ plane.

[0082] As described above, each of the multiple laser beams L emitted in the +Z direction from light-emitting device 100A is reflected in the +X direction by the corresponding reflecting surface 90s. More specifically, laser beam L emitted from each of the multiple laser light sources 20 included in light-emitting device 100A is reflected in the +X direction by first reflecting surface 30as, second reflecting surface 30bs, and reflecting surface 90s, in that order. The multiple laser beams L thus obtained can be combined by condenser lens 70 and incident on optical fiber 80.

[0083] As a result, the light emitting module 200A emits combined light obtained by combining multiple laser beams L from the light emitting end 80b of the optical fiber 80. The output of the combined light is roughly equal to the value obtained by multiplying the output of each laser beam L by the number of laser beams L. Therefore, by increasing the number of laser beams L, the output of the combined light can be increased.

[0084] In this specification, the following three specific directions in embodiment 1 may be numbered. In the light-emitting device 100A, the direction in which the laser light L is emitted from the laser light source 20 is also referred to as the "first direction," and the direction in which the multiple laser light sources 20 are arranged is also referred to as the "second direction." In the light-emitting module 200A, the direction in which the laser light L is reflected by the reflective surface 90s of each mirror member 90 is also referred to as the "third direction." In the above example, the first direction is the +Z direction, the second direction is the +X direction, and the third direction is the +X direction, but these directions are not limited to these. The second direction does not need to be orthogonal to the first direction as long as it intersects with the first direction. The third direction may or may not be parallel to the second direction.

[0085] (Embodiment 2) [Light-Emitting Device] An exemplary configuration of a light-emitting device according to Embodiment 2 of the present disclosure will be described below with reference to FIGS. 4A to 4D. FIG. 4A is a perspective view schematically illustrating the configuration of a light-emitting device according to exemplary Embodiment 2 of the present disclosure. The light-emitting device 100B shown in FIG. 4A can be placed on, for example, a mounting surface of a support base. Details of the support base will be described later in the description of the light-emitting module according to Embodiment 2. FIG. 4B is an exploded perspective view of the light-emitting device shown in FIG. 4A. The light-emitting device 100B shown in FIG. 4B includes a base 10B, a plurality of first laser light sources 20a, a plurality of second laser light sources 20b, a plurality of first mirror members 30a, a second mirror member 30b, a plurality of third mirror members 30c, a fourth mirror member 30d, a cover 40B, a first slow-axis collimating lens array 50a, a second slow-axis collimating lens array 50b, a first support member 34a, and a second support member 34b. The first slow-axis collimating lens array 50a is integrally formed and includes a plurality of first slow-axis collimating lenses 50as. Similarly, the second slow-axis collimating lens array 50b is integrally formed and includes a plurality of second slow-axis collimating lenses 50bs. In the example shown in FIG. 4B , the number of first laser light sources 20a is three, but this number is not limited thereto. The number of first laser light sources 20a may be two, or four or more. It is preferable that the number of first mirror members 30a and first slow-axis collimating lenses 50as be the same as the number of first laser light sources 20a. Furthermore, the number of second laser light sources 20b is three, but this number is not limited thereto. The number of second laser light sources 20b may be two, or four or more. It is preferable that the number of second mirror members 30b and second slow-axis collimating lenses 50bs be the same as the number of second laser light sources 20b.

[0086] The first laser light source 20a corresponds to the laser light source 20 shown in Fig. 1B. The first mirror member 30a corresponds to the first mirror member 30a shown in Fig. 1B. The second mirror member 30b corresponds to the second mirror member 30b shown in Fig. 1B. The first slow axis collimating lens array 50a corresponds to the slow axis collimating lens array 50 shown in Fig. 1B.

[0087] The light emitting device 100B shown in FIG. 4B differs from the light emitting device 100A shown in FIG. 1B in the following four points.

[0088] The first difference is that the light emitting device 100B includes a base 10B instead of the base 10A. The dimension of the base 10B in the Z direction is greater than the dimension of the base 10A in the Z direction.

[0089] The second point is that the light emitting device 100B includes, in addition to the plurality of first laser light sources 20a and the plurality of first mirror members 30a, a plurality of second laser light sources 20b and a plurality of third mirror members 30c. Each of the third mirror members 30c has a third reflecting surface 30cs.

[0090] 4B includes a fourth mirror member 30d and a second slow-axis collimating lens array 50b in addition to the second mirror member 30b and the first slow-axis collimating lens array 50a. The fourth mirror member 30d has a fourth reflecting surface 30ds.

[0091] The fourth point is that the light emitting device 100B shown in FIG. 4B includes a first support member 34a that supports the fourth mirror member 30d and a second support member 34b that supports the second slow axis collimating lens array 50b.

[0092] Fig. 4C is a top view of the configuration of light emitting device 100B shown in Fig. 4B, omitting lid 40B and components on lid 40B. Fig. 4D is a cross-sectional view parallel to the YZ plane of light emitting device 100B shown in Fig. 4A.

[0093] 4D , the light emitting device 100B according to the second embodiment can emit not only a plurality of first laser beams La but also a plurality of second laser beams Lb traveling above the plurality of first laser beams La. As a result, in a light emitting module including the light emitting device 100B, the number of laser beams that can be combined can be increased, and the output of the combined light can be further increased.

[0094] The components of the light emitting device 100B will be described below. The first laser light source 20a, the first mirror member 30a, the second mirror member 30b, and the first slow axis collimator lens array 50a are as described in the first embodiment.

[0095] <Base 10B> The base 10B differs from the base 10A shown in FIG. 1B in its dimension in the Z direction. In addition to the plurality of first laser light sources 20a and the plurality of first mirror members 30a, the base 10B also houses a plurality of second laser light sources 20b and a plurality of third mirror members 30c. Therefore, the dimension of the base 10B in the Z direction is greater than the dimension of the base 10A in the Z direction. Like the base 10A, the base 10B has a mounting surface 10s, a first upper surface 12a, a second upper surface 12b, and a lower surface 14.

[0096] The dimension of the base 10B in the X direction may be, for example, 7 mm or more and 45 mm or less, the dimension in the Y direction may be, for example, 2 mm or more and 3 mm or less, and the dimension in the Z direction may be, for example, 25 mm or more and 35 mm or less.

[0097] <Second Laser Light Source 20b> The second laser light source 20b has the same structure as the first laser light source 20a. The second laser light source 20b differs from the first laser light source 20a in the position where the second laser light source 20b is disposed. As shown in FIG. 4B , the multiple second laser light sources 20b are disposed rearward of the multiple first laser light sources 20a on the mounting surface 10s of the base 10B. Each first laser light source 20a emits a first laser light La in the +Z direction, and each second laser light source 20b emits a second laser light Lb in the +Z direction. "Rearward" refers to the direction opposite to the direction in which the first laser light La is emitted from each first laser light source 20a and the direction in which the second laser light Lb is emitted from each second laser light source 20b.

[0098] As shown in Fig. 4C, the multiple second laser light sources 20b are arranged along the X direction such that the positions of the multiple laser light sources 20 in the Z direction are different from one another. In the example shown in Fig. 4C, the multiple second laser light sources 20b are arranged so as to be shifted stepwise in the -Z direction along the X direction. The shift direction may not be the -Z direction, but the opposite direction, the +Z direction. Alternatively, the positions of the multiple second laser light sources 20b in the Z direction may be irregular along the X direction.

[0099] When the mounting surface 10s is flush, it is possible to reduce the variation in the amount of heat emitted from the multiple first laser light sources 20a and the multiple second laser light sources 20b during operation and transferred to the mounting surface of the support base. In other words, when the mounting surface 10s is flush, it is possible to uniformly dissipate heat from each laser light source 20. As a result, it is possible to effectively transfer the heat emitted from the multiple first laser light sources 20a and the multiple second laser light sources 20b during operation to the outside of the light emitting device 100B.

[0100] Each second laser light source 20b has the same structure as each first laser light source 20a. In this specification, the semiconductor laser element 22 included in each first laser light source 20a will be referred to as a "first semiconductor laser element," and the semiconductor laser element 22 included in each second laser light source 20b will be referred to as a "second semiconductor laser element." The first semiconductor laser element has a first emission surface, from which first laser light La is emitted in the +Z direction. The second semiconductor laser element has a second emission surface, from which second laser light Lb is emitted in the +Z direction.

[0101] <Third Mirror Element 30c and Fourth Mirror Element 30d> The third mirror element 30c has the same structure as the first mirror element 30a. The third mirror element 30c differs from the first mirror element 30a in its position. As shown in FIG. 4B , the multiple third mirror elements 30c are positioned behind the multiple first mirror elements 30a on the mounting surface 10s of the base 10B. As shown in FIG. 4C , the multiple third mirror elements 30c are positioned along the X direction such that the positions of their third reflecting surfaces 30cs in the Z direction differ from one another. In the example shown in FIG. 4C , the multiple third mirror elements 30c are positioned so as to be shifted in stages in the −Z direction along the X direction, similar to the multiple second laser light sources 20b. The shift direction may not be the −Z direction, but the opposite direction, the +Z direction. Alternatively, the positions of the multiple third mirror elements 30c in the Z direction may be irregular along the X direction.

[0102] 4C , the distances between each of the third mirror members 30c and a corresponding one of the second laser light sources 20b are substantially the same, and are the distances between the point on the third reflecting surface 30cs of each third mirror member 30c where the optical axis of the second laser light Lb strikes and the center of the emission surface of the corresponding second laser light source 20b.

[0103] 4D , each third mirror member 30c, more specifically, its third reflecting surface 30cs, reflects the second laser light Lb emitted from the second laser light source 20b and changes the traveling direction of the second laser light Lb in a direction away from the mounting surface 10s of the base 10B. The angle formed between the traveling direction of the second laser light Lb away from the mounting surface 10s of the base 10B and the normal direction of the mounting surface 10s can be, for example, between 0° and 5°.

[0104] The fourth mirror member 30d has the same structure as the second mirror member 30b. The fourth mirror member 30d differs from the second mirror member 30b in the position where the fourth mirror member 30d is disposed. As shown in FIG. 4A , the fourth mirror member 30d is disposed on the top surface 42 of the cover 40B, behind and above the second mirror member 30b, via the first support member 34a. If the dimension of the fourth mirror member 30d in the Y direction is sufficiently large, there is no need to provide the first support member 34a.

[0105] The fourth mirror member 30d has a fourth reflecting surface 30ds, similar to the second mirror member 30b. A portion of the fourth reflecting surface 30ds is located above at least a portion of the third reflecting surface 30cs of each third mirror member 30c. As shown in FIG. 4D , the fourth mirror member 30d, more specifically, its fourth reflecting surface 30ds, reflects the second laser light Lb reflected by the third reflecting surface 30cs, thereby further changing the traveling direction of the second laser light Lb in the +Z direction.

[0106] Because the fourth mirror member 30d is located above the second mirror member 30b, the plurality of second laser beams Lb reflected by the fourth reflecting surface 30ds travel in the +Z direction without hitting the second mirror member 30b. As a result, the light emitting device 100B can emit the plurality of first laser beams La and the plurality of second laser beams Lb traveling above the plurality of first laser beams La.

[0107] Unlike the multiple third mirror members 30c, the fourth mirror member 30d is a single member, which reduces misalignment of the optical axis due to component misalignment. Multiple individual fourth mirror members 30d may be used instead of the fourth mirror member 30d. Because the positions and orientations of the multiple fourth mirror members 30d can be individually adjusted, it is possible to effectively reduce misalignment between the traveling direction of each of the multiple second laser beams Lb and the +Z direction.

[0108] Because the positions of the multiple third mirror members 30c in the Z direction are different from one another, the heights of the optical axes of the multiple laser beams L reflected by the fourth reflecting surface 30ds are different from one another, with the mounting surface 10s being used as the reference plane for height. In the example shown in Fig. 4D, the multiple third mirror members 30c are arranged so as to be shifted in stages in the -Z direction along the X direction, so the heights of the optical axes of the multiple laser beams L reflected by the fourth reflecting surface 30ds are lowered in stages in the +X direction. The absolute value of the difference in the heights of the optical axes of two adjacent second laser beams Lb among the multiple second laser beams Lb is, for example, 0.3 mm or more and 0.5 mm or less.

[0109] As shown in Fig. 4D, a first resin layer 32a exists between the lower surface of the second mirror member 30b and the upper surface 42 of the cover 40B. The first resin layer 32a corresponds to the resin layer 32 shown in Fig. 1D. Similarly, as shown in Fig. 4D, a second resin layer 32b exists between the lower surface of the fourth mirror member 30d and the upper surface of the first support member 34a. Therefore, like the second mirror member 30b, the position and orientation of the fourth mirror member 30d can be appropriately adjusted.

[0110] <Lid 40B> Like the lid 40A shown in Fig. 1B, the lid 40B has an upper surface 42 and a lower surface 44. The lid 40B differs from the lid 40A shown in Fig. 1B in its dimension in the Z direction and the shape of the light-shielding film 48. The dimension in the Z direction of the lid 40B is greater than the dimension in the Z direction of the lid 40A. The lid 40B is located above the multiple first laser light sources 20a, the multiple second laser light sources 20b, the multiple first mirror members 30a, and the multiple third mirror members 30c.

[0111] The cover 40B transmits the first laser beam La reflected by the first reflecting surface 30as and the second laser beam Lb reflected by the third reflecting surface 30cs. More specifically, the cover 40B has a plurality of first light-transmitting portions 46a and a plurality of second light-transmitting portions 46b. Each first light-transmitting portion 46a transmits the first laser beam La reflected by the first reflecting surface 30as of the corresponding first mirror member 30a, and each second light-transmitting portion 46b transmits the second laser beam Lb reflected by the third reflecting surface 30cs of the corresponding third mirror member 30c.

[0112] The cover 40B has a light-shielding film 48 at least around the periphery of the lower surface of each of the plurality of first light-transmitting portions 46 a and the lower surface of each of the plurality of second light-transmitting portions 46 b on the lower surface 44. In the example shown in Fig. 4B , the light-shielding film 48 is provided on the entire region of the lower surface 44 except for the lower surfaces of each of the plurality of first light-transmitting portions 46 a and the lower surfaces of each of the plurality of second light-transmitting portions 46 b.

[0113] The dimension of the lid 40B in the X direction may be, for example, 6 mm to 44 mm, the dimension in the Y direction may be, for example, 0.1 mm to 1.5 mm, and the dimension in the Z direction may be, for example, 20 mm to 30 mm.

[0114] <Second Slow-Axis Collimating Lens Array 50b> The second slow-axis collimating lens array 50b has the same structure as the first slow-axis collimating lens array 50a. The second slow-axis collimating lens array 50b differs from the first slow-axis collimating lens array 50a in the position where the second slow-axis collimating lens array 50b is disposed. As shown in FIG. 4A , the second slow-axis collimating lens array 50b is disposed on the upper surface 42 of the lid 40B, behind and above the first slow-axis collimating lens array 50a, via the second support member 34b. If the dimension of the second slow-axis collimating lens array 50b in the Y direction is sufficiently large, there is no need to provide the second support member 34b.

[0115] As shown in FIG. 4D , each of the multiple second slow-axis collimating lenses 50bs collimates the second laser light Lb emitted from a corresponding one of the multiple second laser light sources 20b and reflected by the third reflecting surface 30cs and the fourth reflecting surface 30ds in that order in the XZ plane, more specifically, in the slow-axis direction within the XZ plane. Because the second slow-axis collimating lens array 50b is disposed on the upper surface 42 of the cover 40B via the second support member 34b, the second laser light Lb can be collimated before it spreads significantly in the XZ plane. This allows the second slow-axis collimating lens array 50b to be compact. Because the second slow-axis collimating lens array 50b is positioned above the first slow-axis collimating lens array 50a, the second slow-axis collimating lens array 50b can receive the second laser light Lb reflected by the fourth reflecting surface 30ds. Since the second slow-axis collimating lens array 50b is disposed above the first slow-axis collimating lens array 50a, the distance from the third reflecting surface 30cs to the fourth reflecting surface 30ds is longer than the distance from the first reflecting surface 30as to the second reflecting surface 30bs. Therefore, the fourth mirror member 30d may be disposed so that the distance from the fourth mirror member 30d to the second slow-axis collimating lens array 50b is shorter than the distance from the second mirror member 30b to the first slow-axis collimating lens array 50a. By disposing the second slow-axis collimating lens array 50b in this manner, the distance traveled by the light beams emitted from the first laser light sources 20a to reach the first slow-axis collimating lens array 50a can be made equal to the distance traveled by the light beams emitted from the second laser light sources 20b to reach the second slow-axis collimating lens array 50b. That is, the shape of the light emitted from the first slow-axis collimating lens array 50 a and the shape of the light emitted from the second slow-axis collimating lens array 50 b can be made to match. Also, instead of adjusting the distance, the shape of the lens of the first slow-axis collimating lens array 50 a and the shape of the lens of the second slow-axis collimating lens array 50 b may be made different from each other to make the shapes of the light emitted from each slow-axis collimating lens array match, or these methods may be combined.

[0116] The light-emitting device 100B may be virtually divided into two structures by a plane parallel to the XY plane, and the divided structures may be used as sub-light-emitting devices. That is, the light-emitting device 100B may include two sub-light-emitting devices. One sub-light-emitting device includes a plurality of first laser light sources 20a, a plurality of first mirror members 30a, a second mirror member 30b, and a first slow-axis collimating lens array 50a. The other sub-light-emitting device includes a plurality of second laser light sources 20b, a plurality of third mirror members 30c, a fourth mirror member 30d, a second slow-axis collimating lens array 50b, a first support member 34a, and a second support member 34b. The two sub-light-emitting devices are arranged along the Z direction and share the base 10B and the lid 40B. The number of sub-light-emitting devices is not limited to two and may be three or more.

[0117] As described above, according to the light-emitting device 100B of the second embodiment, even if the mounting surface 10s on which the plurality of first laser light sources 20a and the plurality of second laser light sources 20b are mounted is coplanar, the heights of the optical axes of the plurality of first laser light sources La and the heights of the optical axes of the plurality of second laser light sources Lb can be made different from one another using the mounting surface 10s as a reference plane for height. Furthermore, when the mounting surface 10s is coplanar, the variation in the amount of heat generated from the plurality of first laser light sources 20a and the plurality of second laser light sources 20b during operation and transferred to the mounting surface of the support base can be reduced. As a result, the heat generated from the plurality of first laser light sources 20a and the plurality of second laser light sources 20b during operation can be effectively transferred to the outside of the light-emitting device 100B. Furthermore, the light-emitting device 100B can emit not only the plurality of first laser light sources La but also the plurality of second laser light sources Lb traveling above the plurality of first laser light sources La. As a result, in a light-emitting module including the light-emitting device 100B, the number of laser beams that can be combined can be increased, and the output of the combined beam can be further increased.

[0118] The light emitting device 100B can be manufactured, for example, as follows. In a first step, a base 10B, a plurality of first laser light sources 20a, a plurality of second laser light sources 20b, a plurality of first mirror members 30a, a plurality of second mirror members 30b, a plurality of third mirror members 30c, a fourth mirror member 30d, a lid 40B, a first slow-axis collimating lens array 50a, a second slow-axis collimating lens array 50b, a first support member 34a, and a second support member 34b are prepared. In a next step, the plurality of first laser light sources 20a, a plurality of second laser light sources 20b, a plurality of first mirror members 30a, and a plurality of third mirror members 30c are provided on the mounting surface 10s of the base 10B. In a next step, the lid 40B is bonded to the base 10B.

[0119] In the next step, active alignment is performed with the lower surface of the second mirror member 30b in contact with the upper surface 42 of the lid body 40B via the uncured resin. In the next step, the resin is cured to form a first resin layer 32a between the second mirror member 30b and the lid body 40B. In the next step, a first slow-axis collimating lens array 50a is provided on the upper surface 42 of the lid body 40B.

[0120] In the next step, the first support member 34a and the second support member 34b are provided on the upper surface 42 of the lid 40B. In the next step, active alignment is performed with the lower surface of the fourth mirror member 30d in contact with the upper surface of the first support member 34a via uncured resin. In the next step, the resin is cured to form a second resin layer 32b between the fourth mirror member 30d and the upper surface of the first support member 34a. In the next step, a second slow-axis collimating lens array 50b is provided on the upper surface of the second support member 34b.

[0121] 5A to 5C, a configuration example of a light-emitting module according to the second embodiment of the present disclosure will be described. The light-emitting module includes the light-emitting device 100B shown in FIG. 4, but the light-emitting device 100B may be used for other purposes without being employed in the light-emitting module.

[0122] Fig. 5A is a top view schematically showing the configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. Fig. 5B is a side view schematically showing the configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. Fig. 5C is another side view schematically showing the configuration of a light emitting module according to exemplary embodiment 2 of the present disclosure. The light emitting module 200B shown in Figs. 5A to 5C differs from the light emitting module 200A shown in Figs. 3A to 3C in the following three points.

[0123] The first difference is that the light-emitting module 200B includes a support base 60B instead of the support base 60A. The shape of the support base 60B is different from the shape of the support base 60A. The second difference is that the light-emitting module 200B includes a light-emitting device 100B, multiple mirror members 90a, and multiple mirror members 90b instead of the light-emitting device 100A and multiple mirror members 90. Each mirror member 90a has a reflective surface 90as, and each mirror member 90b has a reflective surface 90bs. In this specification, the mirror member 90a and the mirror member 90 shown in FIG. 3A are also referred to as the "fifth mirror member," and their reflective surfaces 90as and 90s are also referred to as the "fifth reflective surface." Similarly, the mirror member 90b is also referred to as the "sixth mirror member," and its reflective surface 90bs is also referred to as the "sixth reflective surface." The third difference is that the light emitting module 200B further includes a mirror member 90c, a half-wave plate 92, an optical element 94, and a polarizing beam splitter 96. The mirror member 90c has a reflecting surface 90cs.

[0124] The support base 60B includes a first portion 60B1 that supports the light emitting device 100B. The support base 60B further includes a plurality of second portions 60B2 supported by the first portion 60B1. The plurality of second portions 60B2 are arranged in two rows. Each row is parallel to the X direction. Each second portion 60B2 included in the first row, which is closer to the light emitting device 100B, supports a corresponding mirror member 90a. Each second portion 60B2 included in the second row, which is farther from the light emitting device 100B, supports a corresponding mirror member 90b. The support base 60B further includes a third portion 60B3 connected to the first portion 60B1. The third portion 60B3 supports the condenser lens 70, the optical fiber 80, the mirror member 90c, the half-wave plate 92, the optical element 94, and the polarizing beam splitter 96.

[0125] The first portion 60B1 has a first mounting surface 60s1. A plurality of second portions 60B2 and the light emitting device 100B are arranged on the first mounting surface 60s1. Each second portion 60B2 has a second mounting surface 60s2. The third portion 60B3 has a third mounting surface 60s3.

[0126] The first mounting surface 60s1 is a plane parallel to the XZ plane. The heights of the multiple second mounting surfaces 60s2 in each of the first and second rows decrease stepwise along the +X direction, as shown in FIG. 5B . A corresponding mirror member 90a is disposed on each second mounting surface 60s2 in the first row, and a corresponding mirror member 90b is disposed on each second mounting surface 60s2 in the second row. If the mirror members 90a and 90b have sufficiently large dimensions in the Y direction, they may be disposed on the first mounting surface 60s1 without the second portion 60B2. The third mounting surface 60s3 is provided with the condenser lens 70, mirror member 90c, half-wave plate 92, optical element 94, and polarizing beam splitter 96, and the optical fiber 80 is disposed via a support member 82.

[0127] The light-emitting device 100B emits a plurality of first laser beams La and a plurality of second laser beams Lb in the +Z direction. In the light-emitting device 100B shown in FIG. 4B , each first laser beam La is emitted from a corresponding first laser light source 20a and reflected by the first reflecting surface 30as and the second reflecting surface 30bs, in this order. In the light-emitting device 100B shown in FIG. 4B , each second laser beam Lb is emitted from a corresponding second laser light source 20b and reflected by the third reflecting surface 30cs and the fourth reflecting surface 30ds, in this order. Each first laser beam La and each second laser beam Lb are collimated in the XZ plane and the YZ plane. As shown in FIG. 5C , the plurality of second laser beams Lb travel above the plurality of first laser beams La. The polarization directions of the plurality of first laser beams La and the plurality of second laser beams Lb are the same, and may be parallel to the X direction, for example. 5A and 5C, the number of first laser beams La is three, but is not limited to three and may be two, four or more. The same applies to the number of second laser beams Lb.

[0128] The reflecting surface 90as of each mirror member 90a reflects the corresponding first laser beam La to change the traveling direction of the first laser beam La to the +X direction. The reflecting surface 90bs of each mirror member 90b reflects the corresponding second laser beam Lb to change the traveling direction of the second laser beam Lb to the +X direction.

[0129] The reflecting surface 90cs of the mirror member 90c reflects the second laser light Lb traveling in the +X direction, thereby changing the traveling direction of the second laser light Lb to the -Z direction.

[0130] The half-wave plate 92 changes the polarization direction of the second laser light Lb traveling in the −Z direction by 90°. The optical element 94 changes the height of the optical axes of the multiple second laser light beams Lb to match the height of the optical axes of the multiple first laser light beams La. The optical element 94 may include, for example, at least one of a wedge, a prism, and two mirror members. The optical element 94 may be a translucent, flat-plate-shaped wedge having parallel light entrance and exit surfaces. The wedge has a uniform cross-sectional shape in the X direction and is arranged so as to tilt from the +Y direction to the −Z direction. When the optical element 94 includes two mirror members, the reflective surface of one of the mirror members receives the second laser light Lb traveling in the −Z direction and changes the traveling direction of the second laser light Lb to the −Y direction. The reflecting surface of the other mirror member receives the second laser light Lb traveling in the −Y direction and changes the traveling direction of the second laser light Lb to the −Z direction.

[0131] The polarizing beam splitter 96 transmits the plurality of first laser beams La traveling in the +X direction and polarized in the Z direction, and reflects the plurality of second laser beams Lb traveling in the −Z direction and polarized in the Y direction. In this manner, the polarizing beam splitter 96 directs the plurality of second laser beams Lb that have passed through the half-wave plate 92 and the plurality of first laser beams La that have not passed through the half-wave plate 92 toward the condenser lens 70. In the example shown in FIG. 5A , the half-wave plate 92 is disposed on the optical path of the plurality of second laser beams Lb, but it may also be disposed on the optical path of the plurality of first laser beams La. In that case, the polarizing beam splitter 96 directs the plurality of first laser beams La that have passed through the half-wave plate 92 and the plurality of second laser beams Lb that have not passed through the half-wave plate 92 toward the condenser lens 70.

[0132] The plurality of first laser beams La and the plurality of second laser beams Lb that have passed through the polarizing beam splitter 96 are combined by the condenser lens 70 and converged at the light incident end 80 a of the optical fiber 80 .

[0133] As described above, each of the multiple first laser beams La emitted in the +Z direction from light-emitting device 100B is reflected in the +X direction by the corresponding reflecting surface 90as, and each of the multiple second laser beams Lb emitted in the +Z direction from light-emitting device 100B is reflected in the +X direction by the corresponding reflecting surface 90bs. More specifically, the first laser beam La emitted from each of the multiple first laser light sources 20a included in light-emitting device 100B is reflected in this order by the first reflecting surface 30as, the second reflecting surface 30bs, and the reflecting surface 90as. The second laser beam Lb emitted from each of the multiple second laser light sources 20b included in light-emitting device 100B is reflected in this order by the third reflecting surface 30cs, the fourth reflecting surface 30ds, and the reflecting surface 90bs. The condenser lens 70 allows the thus obtained plurality of first laser beams La and the plurality of second laser beams Lb to be combined after passing through the polarizing beam splitter 96 and to be incident on the optical fiber 80 .

[0134] As a result, light-emitting module 200B emits combined light in which a plurality of first laser beams La and a plurality of second laser beams Lb are combined, from light-emitting end 80b of optical fiber 80. In light-emitting module 200B shown in Figures 5A to 5C, the total number of first laser beams La and second laser beams Lb is twice the number of laser beams L, as compared to light-emitting module 200A shown in Figures 3A to 3C. Therefore, the output of the combined light can be further increased.

[0135] In this specification, the following three specific directions in embodiment 2 may be numbered. In light-emitting device 100B, the direction in which first laser light source 20a emits first laser light La and the direction in which second laser light source 20b emits second laser light Lb are also referred to as the "first direction." The direction that intersects with the first direction and in which the multiple first laser light sources 20a and the multiple second laser light sources 20b are arranged is also referred to as the "second direction." In light-emitting module 200B, the direction in which first laser light La is reflected by the reflecting surface 90as of each mirror member 90a and the direction in which second laser light Lb is reflected by the reflecting surface 90bs of each mirror member 90b are also referred to as the "third direction."

[0136] In the above example, the first direction is the +Z direction, the second direction is the +X direction, and the third direction is the +X direction, but these directions are not limited to these. The second direction does not need to be perpendicular to the first direction as long as it intersects with the first direction. The third direction may or may not be parallel to the second direction.

[0137] [Configuration of laser light source 20] Next, an example of the configuration of the laser light source 20 shown in Fig. 1B will be described with reference to Fig. 6A and Fig. 6B. Fig. 6A is an exploded perspective view of the laser light source 20. Fig. 6B 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.

[0138] As shown in FIG. 6A , the submount 21 has an upper surface 21s1 and a lower surface 21s2 that are parallel to the XZ plane. A metal film is provided on the upper surface 21s1, and the semiconductor laser element 22 and the lens support member 23 are bonded to the submount 21 by, for example, an inorganic bonding material provided on the metal film. The metal film provided on the upper surface 21s1 may also be used to supply power to the semiconductor laser element 22. A metal film is also provided on the lower surface 21s2, and the base 10A shown in FIG. 1B is bonded to the laser light source 20 by, for example, an inorganic bonding material provided on the metal film. The metal films provided on each of the upper surface 21s1 and the lower surface 21s2 also help to transfer heat generated by the semiconductor laser element 22 during operation to the base 10A via the submount 21. The submount 21 can be formed from the above-mentioned ceramics, metal materials, or metal matrix composite materials, similar to the support base 60A shown in FIGS. 3A and 3B, for example.

[0139] As shown in FIG. 6A , the semiconductor laser element 22 is supported by the upper surface 21s1 of the submount 21. The semiconductor laser element 22 has an emission surface 22e, one of two end surfaces intersecting 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 major axis in the Y direction and the minor axis in the X direction.

[0140] 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 peak emission wavelength of the violet light is preferably in the range of 400 nm to 420 nm, and more preferably in the range of 400 nm to 415 nm. The peak emission wavelength of the blue light is preferably in the range of more than 420 nm to 495 nm, and more preferably in the range of 440 nm to 475 nm. The peak emission wavelength of the green light is preferably in the range of more than 495 nm to 570 nm, and more preferably in the range of 510 nm to 550 nm. The peak emission wavelength of the red light is preferably in the range of 605 nm to 750 nm, and more preferably in the range of 610 nm to 700 nm.

[0141] The semiconductor laser element 22 emitting violet, blue, and green laser beams may be a laser diode containing a nitride semiconductor material, such as GaN, InGaN, or AlGaN. The semiconductor laser element 22 emitting red laser beams may be a laser diode containing an InAlGaP-based, GaInP-based, GaAs-based, or AlGaAs-based semiconductor material, for example.

[0142] As shown in FIG. 6A , the lens support member 23 is supported by the upper surface 21s1 of the submount 21. The lens support member 23 has two columnar portions 23a and a connecting portion 23b located between the two columnar portions 23a and connecting the two columnar portions 23a. The two columnar portions 23a are located on both sides of the semiconductor laser element 22, and the connecting portion 23b is located above the emission surface 22e of the semiconductor laser element 22. The lens support member 23 supports the fast axis collimating lens 24 by end faces 23as of the two columnar portions 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.

[0143] 1A and 1B, the lens support member 23 may be made of the aforementioned ceramics, or may be made of the aforementioned light-transmitting material, like the lid 40A shown in Fig. 1A and 1B. The lens support member 23 may also be made of, for example, an alloy such as Kovar or CuW, or Si.

[0144] As shown in FIG. 6A , 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 on the exit surface 22 e of the semiconductor laser element 22. As shown in FIG. 6B , the fast axis collimating lens 24 collimates, in the YZ plane, the laser light emitted in the +Z direction from the exit surface 22 e of the semiconductor laser element 22. The region surrounded by the dashed line in FIG. 6B is where the intensity of the laser light is 1 / e of its peak intensity. ２ 1A and 1B, the fast axis collimating lens 24 may be formed from the above-mentioned light-transmitting material, similar to the lid 40A shown in FIG. 1A and FIG. 1B.

[0145] 1B , the fast axis collimating lens 24 is located between the mounting surface 10s of the base 10A and the lower surface 44 of the lid 40A, and is located on the optical path of the laser light L. Because the fast axis collimating lens 24 is disposed inside the sealed space formed by the base 10A and the lid 40A, it can collimate the laser light L before it diverges significantly. This makes it possible to make the fast axis collimating lens 24 compact.

[0146] Instead of the fast axis collimating lens 24, 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. In this case, it is not necessary to provide the slow axis collimating lens array 50 in the light emitting device 100A. The same applies to the first slow axis collimating lens array 50a and the second slow axis collimating lens array 50b in the light emitting device 100B.

[0147] The present disclosure includes light-emitting devices and light-emitting modules described in the following items: [Item 1] A light-emitting device comprising: a base having a mounting surface; a plurality of semiconductor laser elements each having an emission surface that emits laser light in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of first mirror members each having a first reflection surface that reflects the laser light emitted from a corresponding semiconductor laser element among the plurality of semiconductor laser elements and changing the traveling direction of the laser light in a direction away from the mounting surface; a lid having an opposing surface facing the mounting surface and an upper surface located opposite the opposing surface, positioned above the plurality of semiconductor laser elements and the plurality of first mirror members and transmitting the laser light reflected by the first reflection surface; and a second mirror member positioned on the upper surface of the lid, having a second reflection surface that reflects the laser light that has passed through the lid and further changing the traveling direction of the laser light, wherein the plurality of first mirror members are arranged on the mounting surface such that the positions of the first reflection surfaces in the first direction are different from each other. [Item 2] The light emitting device according to item 1, wherein a plurality of distances defined by the distance between each of the plurality of first mirror members and a corresponding semiconductor laser element among the plurality of semiconductor laser elements are substantially the same. [Item 3] The light emitting device according to item 1 or 2, wherein the mounting surface on which the plurality of semiconductor laser elements are mounted is flush with one another. [Item 4] The light emitting device according to any one of items 1 to 3, wherein the plurality of first mirror members are arranged so as to be shifted stepwise along the second direction in the same direction as the first direction or in the opposite direction. [Item 5] The light emitting device according to any one of items 1 to 4, further comprising a plurality of housings arranged on the mounting surface, each housing housing housing one semiconductor laser element among the plurality of semiconductor laser elements and one first mirror member among the plurality of first mirror members corresponding to the one semiconductor laser element.[Item 6] The light emitting device according to any one of items 1 to 5, further comprising a plurality of fast axis collimating lenses located between the mounting surface of the base and the facing surface of the lid, wherein each of the plurality of fast axis collimating lenses collimates, in the fast axis direction, the laser light emitted from a corresponding semiconductor laser element among the plurality of semiconductor laser elements. [Item 7] The light emitting device according to any one of items 1 to 6, further comprising a plurality of slow axis collimating lenses located on the upper surface of the lid, wherein each of the plurality of slow axis collimating lenses collimates, in the slow axis direction, the laser light emitted from a corresponding semiconductor laser element among the plurality of semiconductor laser elements and reflected by the first reflecting surface and the second reflecting surface in this order. [Item 8] The light emitting device according to item 7, wherein the plurality of slow axis collimating lenses are integrally formed. [Item 9] The light emitting device according to any one of items 1 to 8, wherein the base includes a region formed from a material having a thermal conductivity of 10 W / m·K or more and 2000 W / m·K or less. [Item 10] The light emitting device according to any one of items 1 to 9, wherein the plurality of semiconductor laser elements are hermetically sealed by the base and the lid. [Item 11] The light emitting device according to item 3, wherein, of a plurality of laser beams obtained by reflecting the laser beam emitted from each of the plurality of semiconductor laser elements by the first reflecting surface and the second reflecting surface in this order, the absolute value of the difference in height from the mounting surface between the optical axes of two adjacent laser beams is 0.3 mm or more and 0.5 mm or less. [Item 12] A light emitting device comprising: a plurality of sub-light emitting devices each being the light emitting device according to any one of items 1 to 11, the plurality of sub-light emitting devices being arranged along the first direction, and the plurality of sub-light emitting devices sharing the base and the lid.[Item 13] A base having a mounting surface; a plurality of first semiconductor laser elements each having a first emission surface that emits a first laser light in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of second semiconductor laser elements each having a second emission surface that emits a second laser light in the first direction and arranged on the mounting surface along the second direction; a plurality of first mirror members each having a first reflection surface that reflects the first laser light emitted from a corresponding first semiconductor laser element among the plurality of first semiconductor laser elements and changing the traveling direction of the first laser light in a direction away from the mounting surface; and a plurality of third mirror members each having a third reflection surface that reflects the second laser light emitted from a corresponding second semiconductor laser element among the plurality of second semiconductor laser elements and changing the traveling direction of the second laser light in a direction away from the mounting surface. a lid body having an opposing surface facing the mounting surface and an upper surface located opposite to the opposing surface, the lid body being located above the plurality of first semiconductor laser elements, the plurality of first mirror members, the plurality of second semiconductor laser elements, and the plurality of third mirror members, and transmitting the first laser light reflected at the first reflecting surface and the second laser light reflected at the third reflecting surface; a second mirror member being located on the upper surface of the lid body, having a second reflecting surface that reflects the first laser light that has passed through the lid body, and further changing the traveling direction of the first laser light; and a fourth mirror member being located on the upper surface of the lid body in a direction opposite to the first direction relative to the second mirror member, and having a fourth reflecting surface that reflects the second laser light that has passed through the lid body, and further changing the traveling direction of the second laser light, wherein the plurality of second semiconductor laser elements are located in a direction opposite to the first direction relative to the plurality of first semiconductor laser elements, and the plurality of first mirror members are located on the mounting surface such that positions of the first reflecting surfaces in the first direction are different from each other, a light emitting device, wherein the plurality of third mirror members are arranged on the mounting surface so that the positions of the third reflecting surfaces in the first direction are different from each other and in a direction opposite to the first direction relative to the plurality of first mirror members.[Item 14] A light emitting module comprising: the light emitting device according to any one of items 1 to 11; a plurality of fifth mirror members, each having a fifth reflecting surface, which reflects the laser light emitted from a corresponding semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order, in a third direction; and a focusing lens which couples the plurality of laser light beams obtained by the laser light emitted from each of the plurality of semiconductor laser elements being reflected by the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order, into an optical fiber. [Item 15] A light emitting module comprising: the light emitting device according to Item 13; a plurality of fifth mirror members, each having a fifth reflecting surface, which reflects, in a third direction, the first laser light emitted from a corresponding first semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order; a plurality of sixth mirror members, each having a sixth reflecting surface, which reflects, in the third direction, the second laser light emitted from a corresponding second semiconductor laser element and reflected by the third reflecting surface and the fourth reflecting surface in this order; and a focusing lens that couples, into an optical fiber, a plurality of first laser light beams obtained by the first laser light emitted from each of the plurality of first semiconductor laser elements being reflected by the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order, and a plurality of second laser light beams obtained by the second laser light emitted from each of the plurality of second semiconductor laser elements being reflected by the third reflecting surface, the fourth reflecting surface, and the sixth reflecting surface in this order. Item 16: The light emitting module according to Item 15, further comprising: a half-wave plate arranged on an optical path of the plurality of first laser beams or an optical path of the plurality of second laser beams, the half-wave plate being the same as a polarization direction of the first laser beam emitted from each of the plurality of second semiconductor laser elements; and a polarizing beam splitter that directs the plurality of first laser beams that have passed through the half-wave plate and the plurality of second laser beams that have not passed through the half-wave plate toward the focusing lens, or that directs the plurality of second laser beams that have passed through the half-wave plate and the plurality of first laser beams that have not passed through the half-wave plate toward the focusing lens.

[0148] The light emitting device and light emitting module of the present disclosure can be used, in particular, to combine multiple laser beams to achieve high-power laser beams, and can be used, for example, in industrial fields requiring high-power laser light sources, such as cutting, drilling, local heat treatment, surface treatment, metal welding, and 3D printing of various materials.

[0149] 10A, 10B: base 10h: housing 10s: mounting surface 12a: first upper surface 12b: second upper surface 14: lower surface 16: bonding region 20: laser light source 20a: first laser light source 20b: second laser light source 21: submount 21s1: upper surface 21s2: lower surface 22: semiconductor laser element 22e: emission surface 23: lens support member 23a: columnar portion 23as: end surface 23b: connecting portion 24: fast axis collimating lens 30a: first mirror member 30as: first reflecting surface 30b: second mirror member 30bs: second reflecting surface 30c: third mirror member 30cs: third reflecting surface 30d: fourth mirror member 30ds: fourth reflecting surface 32: resin layer 32a: first resin layer 32b: Second resin layer 34a: First support member 34b: Second support member 40A, 40B: Lid 42: Upper surface 44: Lower surface 46: Light-transmitting portion 46a: First light-transmitting portion 46b: Second light-transmitting portion 48: Light-shielding film 50: Slow-axis collimating lens array 50s: Slow-axis collimating lens 50a: First slow-axis collimating lens array 50as: First slow-axis collimating lens 50b: Second slow-axis collimating lens array 50bs: Second slow-axis collimating lens 60A, 60B: Support base 60A1, 60B1: First portion 60A2, 60B2: Second portion 60A3, 60B3: Third portion 60s1: First mounting surface 60s2: Second mounting surface 60s3: third mounting surface 70: condenser lens 70a: fast axis condenser lens 70b: slow axis condenser lens 80: optical fiber 80a: light input end 80b: light output end 82: support member 90, 90a, 90b, 90c: mirror member 90s, 90as, 90bs, 90cs: reflecting surface 92: half wavelength plate 94: optical element 96: polarizing beam splitter 100A, 110A, 120A, 100B: light emitting device 200A, 200B: light emitting module L: laser light La: first laser light Lb: second laser light Ref: reference plane

Claims

1. a base having a mounting surface; a plurality of semiconductor laser elements each having an emission surface for emitting laser light in a first direction, the semiconductor laser elements being arranged on the mounting surface along a second direction intersecting the first direction; a plurality of first mirror members each having a first reflecting surface that reflects the laser light emitted from a corresponding one of the plurality of semiconductor laser elements and that changes the traveling direction of the laser light to a direction away from the mounting surface; a lid having an opposing surface facing the mounting surface and an upper surface located on the opposite side of the opposing surface, the lid being located above the plurality of semiconductor laser elements and the plurality of first mirror members, and transmitting the laser light reflected by the first reflecting surface; one or more second mirror members disposed on the upper surface of the lid, the second mirror members having a second reflecting surface that reflects the laser light that has passed through the lid, and further changing the traveling direction of the laser light; Equipped with the first mirror members are disposed on the mounting surface such that positions of the first reflecting surfaces in the first direction are different from one another; a mounting surface being a reference surface, and heights of optical axes of the laser light reflected by the second reflecting surface from the reference surface being different from each other.

2. The light emitting device according to claim 1 , wherein a plurality of distances defined by the distance between each of the plurality of first mirror members and a corresponding one of the plurality of semiconductor laser elements are substantially the same.

3. 3. The light emitting device according to claim 1, wherein the mounting surface on which the plurality of semiconductor laser elements are mounted is flush with one another.

4. The light emitting device according to claim 1 , wherein the first mirror members are arranged so as to be shifted stepwise along the second direction in a direction the same as or opposite to the first direction.

5. Further comprising a plurality of housings arranged on the mounting surface, The light emitting device according to claim 2 , wherein each of the plurality of housings accommodates one semiconductor laser element of the plurality of semiconductor laser elements and a first mirror member of the plurality of first mirror members that corresponds to the one semiconductor laser element.

6. a plurality of fast axis collimating lenses positioned between the mounting surface of the base and the opposing surface of the lid; 3 . The light emitting device according to claim 1 , wherein each of the plurality of fast axis collimating lenses collimates, in a fast axis direction, the laser light emitted from a corresponding one of the plurality of semiconductor laser elements.

7. Further comprising a plurality of slow axis collimating lenses disposed on the top surface of the lid, 3. The light emitting device according to claim 1, wherein each of the plurality of slow axis collimating lenses collimates, in a slow axis direction, the laser light emitted from a corresponding one of the plurality of semiconductor laser elements and reflected by the first reflecting surface and the second reflecting surface in this order.

8. The light emitting device according to claim 7 , wherein the plurality of slow axis collimating lenses are integrally formed.

9. The light emitting device according to claim 1 , wherein the base portion includes a region formed from a material having a thermal conductivity of 10 W / m·K or more and 2000 W / m·K or less.

10. 3. The light emitting device according to claim 1, wherein said plurality of semiconductor laser elements are hermetically sealed by said base and said lid.

11. 3. The light emitting device according to claim 1, wherein, among a plurality of laser beams obtained by reflecting the laser beam emitted from each of the plurality of semiconductor laser elements by the first reflecting surface and the second reflecting surface in this order, an absolute value of a difference in height of optical axes of two adjacent laser beams from the mounting surface is 0.3 mm or more and 0.5 mm or less.

12. A light emitting device according to claim 1, The plurality of sub-light emitting devices are arranged along the first direction, A light emitting device, wherein the plurality of sub-light emitting devices share the base and the lid.

13. a base having a mounting surface; a plurality of first semiconductor laser elements each having a first emission surface that emits a first laser light in a first direction and arranged on the mounting surface along a second direction intersecting the first direction; a plurality of second semiconductor laser elements each having a second emission surface that emits a second laser light in the first direction and arranged on the mounting surface along the second direction; a plurality of first mirror members each having a first reflecting surface that reflects the first laser light emitted from a corresponding one of the plurality of first semiconductor laser elements and that changes a traveling direction of the first laser light to a direction away from the mounting surface; a plurality of third mirror members each having a third reflection surface that reflects the second laser light emitted from a corresponding one of the plurality of second semiconductor laser elements and changes a traveling direction of the second laser light to a direction away from the mounting surface; and a lid having an opposing surface facing the mounting surface and an upper surface located on the opposite side to the opposing surface, the lid being located above the plurality of first semiconductor laser elements, the plurality of first mirror members, the plurality of second semiconductor laser elements, and the plurality of third mirror members, and transmitting the first laser light reflected by the first reflecting surface and the second laser light reflected by the third reflecting surface; a second mirror member disposed on the upper surface of the lid body, the second mirror member having a second reflecting surface that reflects the first laser light that has passed through the lid body, and further changing the traveling direction of the first laser light; a fourth mirror member disposed on the upper surface of the lid body in a direction opposite to the first direction with respect to the second mirror member, the fourth mirror member having a fourth reflection surface that reflects the second laser light that has passed through the lid body, and further changing the traveling direction of the second laser light; Equipped with the second semiconductor laser elements are arranged in a direction opposite to the first direction relative to the first semiconductor laser elements, the first mirror members are disposed on the mounting surface such that positions of the first reflecting surfaces in the first direction are different from one another; a light emitting device, wherein the third mirror members are arranged on the mounting surface such that the positions of the third reflecting surfaces in the first direction are different from each other and in a direction opposite to the first direction relative to the first mirror members;

14. A light emitting device according to claim 1 or 2; a plurality of fifth mirror members each having a fifth reflecting surface, the fifth reflecting surface reflecting the laser light emitted from a corresponding semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order, in a third direction; a condenser lens that couples a plurality of laser beams obtained by the laser beams emitted from the respective semiconductor laser elements being reflected by the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order into an optical fiber; A light emitting module comprising:

15. A light emitting device according to claim 13; a plurality of fifth mirror members each having a fifth reflecting surface that reflects, in a third direction, the first laser light emitted from a corresponding first semiconductor laser element and reflected by the first reflecting surface and the second reflecting surface in this order; a plurality of sixth mirror members each having a sixth reflecting surface that reflects the second laser light emitted from a corresponding second semiconductor laser element and reflected by the third reflecting surface and the fourth reflecting surface in this order in the third direction; a focusing lens that couples, into an optical fiber, a plurality of first laser beams obtained by reflecting the first laser beam emitted from each of the plurality of first semiconductor laser elements on the first reflecting surface, the second reflecting surface, and the fifth reflecting surface in this order, and a plurality of second laser beams obtained by reflecting the second laser beam emitted from each of the plurality of second semiconductor laser elements on the third reflecting surface, the fourth reflecting surface, and the sixth reflecting surface in this order; A light emitting module comprising:

16. a polarization direction of the second laser light emitted from each of the plurality of second semiconductor laser elements is the same as a polarization direction of the first laser light emitted from each of the plurality of first semiconductor laser elements, a half-wave plate disposed on an optical path of the plurality of first laser beams or an optical path of the plurality of second laser beams; a polarizing beam splitter that directs the plurality of first laser beams that have passed through the half-wave plate and the plurality of second laser beams that have not passed through the half-wave plate to the condensing lens, or directs the plurality of second laser beams that have passed through the half-wave plate and the plurality of first laser beams that have not passed through the half-wave plate to the condensing lens; The light emitting module of claim 15 further comprising: