Light-emitting device and light-emitting module

Abstract

The present invention realizes a small-sized light-emitting device which emits light having different polarization directions. The light-emitting device comprises: a plurality of semiconductor laser elements having light emitting peak wavelengths of a first wavelength±20 nm or less; and a plurality of reflection members including a first reflection member having a first light reflection surface and a second reflection member having a second light reflection surface and a wavelength plate which is provided on the second light reflection surface. The plurality of semiconductor laser elements include a first semiconductor laser element and a second semiconductor laser element. Light emitted from the first semiconductor laser element is reflected by the first light reflection surface of the first reflection member. Light emitted from the second semiconductor laser element is reflected by the second light reflection surface of the second reflection member. Light incident on the first light reflection surface and light incident on the second light reflection surface have the same polarization direction. Light emitted from the first reflection member and light emitted from the second reflection member have different polarization directions.

Description

Light emitting device and light emitting module

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

[0002] WO2020 / 66868 discloses a laser light source device including a plurality of semiconductor laser elements, a polarization rotation element, a plurality of lenses, a spacer that supports the polarization rotation elements and the plurality of lenses, and a base on which the plurality of semiconductor laser elements are arranged and to which the spacer is fixed. The spacer has a plurality of stepped portions for supporting the polarization rotation elements, and by supporting the polarization rotation elements by desired stepped portions, it is possible to rotate the polarization of light emitted from the desired semiconductor laser elements.

[0003] WO2020 / 66868

[0004] The disclosed laser light source device, regardless of whether or not a polarization rotation element is used, has a plurality of step portions provided in the spacer, which results in an increase in the size of the device.

[0005] An invention is disclosed that solves the problem of realizing a small light emitting device or light emitting module that emits light with different polarization directions.

[0006] Alternatively, instead of the above-mentioned problem, an invention is disclosed that solves the problem of realizing a small light emitting device or light emitting module that emits light with a uniform polarization direction.

[0007] Alternatively, instead of the above-mentioned problems, an invention is disclosed that solves the problem of realizing a light emitting device or a light emitting module that efficiently emits desired light.

[0008] Alternatively, instead of the above-mentioned problems, an invention is disclosed that solves the problem of realizing efficient production of light emitting devices or light emitting modules.

[0009] This specification also discloses inventions that solve multiple of the above-mentioned problems in a composite manner.

[0010] a light emitting device disclosed in an embodiment, comprising: a package; a plurality of semiconductor laser elements arranged in an internal space of the package, each having an emission peak wavelength within ±20 nm of a first wavelength; and a plurality of reflecting members arranged in the internal space of the package, the plurality of reflecting members including one or more first reflecting members having a first light reflecting surface, and one or more second reflecting members having a second light reflecting surface and a wave plate provided on the second light reflecting surface, wherein the plurality of semiconductor laser elements include one or more first semiconductor laser elements and one or more second semiconductor laser elements, wherein light emitted from the one or more first semiconductor laser elements is reflected by the first light reflecting surface of the one or more first reflecting members, and light emitted from the one or more second semiconductor laser elements is reflected by the second light reflecting surface of the one or more second reflecting members, and wherein the polarization directions of the light incident on the first light reflecting surface and the light incident on the second light reflecting surface are the same, and the polarization directions of the light emitted from the first reflecting member and the second reflecting member are different.

[0011] Moreover, the light emitting module disclosed in the embodiment comprises a first light emitting device mounted on the substrate, the first light emitting device comprising: a substrate; a first package; one or more first semiconductor laser elements disposed in the internal space of the first package and having an emission peak wavelength within ±20 nm of a first wavelength; and one or more first reflecting members disposed in the internal space of the first package and having a first light reflecting surface; and a second light emitting device mounted on the substrate, the second light emitting device comprising: a second package; one or more second semiconductor laser elements disposed in the internal space of the second package and having an emission peak wavelength within ±20 nm of the first wavelength; and one or more second reflecting members disposed in the internal space of the second package and having a second light reflecting surface and a wave plate provided on the second light reflecting surface.

[0012] In at least one of one or more inventions disclosed in the embodiments, it is possible to realize a small-sized light emitting device or light emitting module that emits light beams with different polarization directions.

[0013] 11A and 11B are perspective views of light emitting devices according to the first, second, fifth, and sixth embodiments; FIG. 12A is a side view of the light emitting devices according to the first, second, fifth, and sixth embodiments; FIG. 13B is a cross-sectional view taken along the III-III cross-section line of FIG. 1; FIG. 14A is a perspective view showing components arranged in the internal space of a package according to each embodiment; FIG. 15A is a top view showing components arranged in the internal space of a package according to the first and fifth embodiments; FIG. 16A is a top view for explaining light emitted from the light emitting device according to the first embodiment; FIG. 17A is a side view of a first reflecting member according to each embodiment; FIG. 18A is a side view of a second reflecting member according to each embodiment; FIG. 19A is a top view showing components arranged on a submount according to each embodiment; FIG. 19B is a side view showing components arranged on a submount according to each embodiment; FIG. 19B is a schematic side view for explaining a lower limit incident angle and an upper limit incident angle for the second reflecting member according to each embodiment; FIG. 19B is a perspective view of a package according to each embodiment; FIG. 19B is a cross-sectional view taken along the XII-XII cross-section line of FIG. 11; FIG. 19C is a top view of a base according to each embodiment; FIG. 20A is a bottom view of a base according to each embodiment; FIG. 21B is a cross-sectional view taken along the XV-XV cross-section line of FIG. 21C; FIG. 22A is a top view showing components arranged in the internal space of a package according to the second embodiment; FIG. 23A is a top view for explaining light emitted from the light emitting device according to the second embodiment. FIG. 10 is a side view of a light emitting device according to a third embodiment. FIG. 11 is a top view illustrating light emitted from the light emitting device according to the third embodiment. FIG. 12 is a side view of a light emitting device according to a fourth embodiment. FIG. 13 is a top view illustrating light emitted from the light emitting device according to the fourth embodiment. FIG. 14 is a top view illustrating light emitted from the light emitting device according to the fifth embodiment. FIG. 15 is a perspective view of a light emitting module according to a sixth embodiment. FIG. 16 is a top view illustrating components arranged in the internal space of the package of a first light emitting device according to a sixth embodiment. FIG. 17 is a top view illustrating light emitted from the first light emitting device according to a sixth embodiment. FIG. 18 is a top view illustrating components arranged in the internal space of the package of a second light emitting device according to a sixth embodiment. FIG. 19 is a top view illustrating light emitted from the second light emitting device according to a sixth embodiment.

[0014] In this specification and claims, polygons such as triangles and quadrilaterals are referred to as polygons, including shapes in which the corners of the polygons have been rounded, chamfered, corner-cut, rounded, etc. Furthermore, shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle portions 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.

[0015] The same applies to words that describe specific shapes, such as trapezoids, circles, and irregularities, not just polygons. The same also applies when dealing with the sides that form the shape. In other words, even if the corners or middle part of a side are processed, the interpretation of "side" includes the processed part. Note that when distinguishing a "polygon" or "side" that has no processing from a processed shape, the word "strict" is added, for example, "strict quadrangle."

[0016] Furthermore, in this specification or claims, descriptions such as up and down (upper / lower), left and right, front and back, front and back (front / rear), front and back, etc. merely describe relationships such as relative positions, orientations, directions, etc., and do not necessarily correspond to the relationships during use.

[0017] In the drawings, directions such as the X direction, Y direction, and Z direction may be indicated using arrows. The directions of these arrows are consistent among multiple drawings relating to the same embodiment. In the drawings, the direction of an arrow marked with X, Y, and Z is the positive direction, and the opposite direction is the negative direction. For example, a direction marked with X at the end of an arrow is the X direction and the positive direction. In this specification, a direction that is the X direction and the positive direction is referred to as the "positive X direction," and the opposite direction is referred to as the "negative X direction." When referring to the "X direction," it is intended to include both the positive and negative directions. The same applies to the Y direction and the Z direction.

[0018] Furthermore, in this specification, when a certain object is described by specifying "one or more," both the form in which there is one object and the form in which there is more than one object are described together. Therefore, the description specifying "one or more" supports any of the following embodiments: an embodiment including one or more objects, an embodiment including at least one object, and an embodiment including more than one object.

[0019] Furthermore, in this specification, a description of "one or each" object is a description that compiles a description of one object in an embodiment that includes one object, a description of one object in an embodiment that includes multiple objects, and a description of each of multiple objects in an embodiment that includes multiple objects. Therefore, a description of "one or each" object supports all of the following: in an embodiment that includes one object, this one object has the explanatory content; in an embodiment that includes multiple objects, at least one of these objects has the explanatory content; in an embodiment that includes multiple objects, each of these multiple objects has the explanatory content; and in an embodiment that includes one or multiple objects, all of the objects have the explanatory content.

[0020] Furthermore, in this specification, the terms "component" and "part" may be used when describing components, for example. A "component" refers to an object that is handled physically as a single unit. An object that is handled physically as a single unit can also be said to be an object that is handled as a single component in the manufacturing process. On the other hand, a "part" refers to an object that does not need to be handled physically as a single unit. For example, the term "part" is used when referring to a portion of a single component, or when referring to multiple components collectively as a single object.

[0021] The distinction between "component" and "part" above does not indicate a conscious intention to limit the scope of rights in the interpretation of the doctrine of equivalents. In other words, even if a component is described as a "component" in the claims, this does not mean that the applicant recognizes that treating this component as a single physical unit is essential for the application of the present invention.

[0022] Furthermore, in this specification or claims, when there are multiple elements of a certain type and they are to be distinguished from one another, the elements may be prefixed with "first" or "second." Furthermore, the objects distinguished between the specification and the claims may differ. Therefore, even if the claims describe elements with the same prefixes as the specification, the objects identified by these elements may not be the same between the specification and the claims.

[0023] For example, if there are elements in this specification that are distinguished by the notation "first," "second," and "third," and the elements marked with "first" and "third" in this specification are described in the claims, the elements may be distinguished by the notation "first" and "second" in the claims for ease of reading. In this case, the elements marked with "first" and "second" in the claims refer to the elements marked with "first" and "third" in this specification, respectively. Note that this rule is not limited to elements, and can be applied rationally and flexibly to other objects as well.

[0024] Hereinafter, embodiments for carrying out the present invention will be described. Furthermore, specific embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiments for carrying out the present invention are not limited to these specific embodiments. In other words, the illustrated embodiments are not the only embodiments in which the present invention can be realized. Note that the sizes and positional relationships of components shown in each drawing may be exaggerated for ease of understanding.

[0025] First Embodiment A light emitting device 1 according to a first embodiment will be described. FIGS. 1 to 15 are diagrams illustrating an exemplary embodiment of the light emitting device 1. FIG. 1 is a perspective view of the light emitting device 1. FIG. 2 is a side view of the light emitting device 1. FIG. 3 is a cross-sectional view of the light emitting device 1 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the light emitting device 1. FIG. 5 is a top view showing components disposed in the internal space of the package 10 of the light emitting device 1. Note that the wiring 60 is not shown in FIG. 5. FIG. 6 is a top view illustrating light emitted from the light emitting device 1. Note that hatching indicates the shape of the light emitted from the light emitting device 1. Furthermore, L1 and L2 indicate light beams with different polarization directions, and are hatched differently. FIG. 7A is a side view of a first reflecting member 40A. FIG. 7B is a side view of a second reflecting member 40B. FIG. 8 is a top view showing components disposed on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view illustrating the lower limit incident angle θ1 and the upper limit incident angle θ2 for the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-sectional line in FIG. 11. FIG. 13 is a top view of the base 11. FIG. 14 is a bottom view of the base 11. FIG. 15 is a cross-sectional view of the base 11 taken along the XV-XV cross-sectional line in FIG. 13.

[0026] The light emitting device 1 includes a plurality of components, including a package 10, a plurality of semiconductor laser elements 20, one or more submounts 30, a plurality of reflecting members 40, one or more protective elements 50, a plurality of wirings 60, and an optical member 70.

[0027] The light emitting device 1 may include other components. For example, the light emitting device 1 may include a semiconductor laser element in addition to one or more semiconductor laser elements 20. The light emitting device 1 may not include some of the components listed here.

[0028] First, each component will be described.

[0029] (Package 10) The package 10 includes a base 11 and a lid 14. The lid 14 is joined to the base 11 to form the package 10. An internal space is defined in the package 10 in which other components are placed. This internal space is a closed space surrounded by the base 11 and the lid 14. This internal space can also be a space sealed in a vacuum or airtight state.

[0030] When viewed from above, the outer edge of the package 10 has a rectangular shape. This rectangle can have long and short sides. In the illustrated package 10, the long side of the rectangle is oriented in the X direction, and the short side is oriented in the Y direction. However, when viewed from above, the outer edge of the package 10 does not have to have a rectangular shape.

[0031] The package 10 defines an internal space in which other components are placed. The first upper surface 11A of the package 10 is part of the area that defines the internal space. In addition, each of the inner side surfaces 11E and the lower surface 14B of the package 10 is also part of the area that defines the internal space.

[0032] The base 11 has a first upper surface 11A and a lower surface 11B. The base 11 has a second upper surface 11C. The base 11 has one or more outer surfaces 11D. The base 11 has one or more inner surfaces 11E. The one or more outer surfaces 11D intersect with the second upper surface 11C. The one or more outer surfaces 11D intersect with the lower surface 11B. The one or more inner surfaces 11E intersect with the second upper surface 11C.

[0033] When viewed from above, the outer edge shape of the base 11 is rectangular. When viewed from above, the outer edge shape of the base 11 is the outer edge shape of the package 10. When viewed from above, the outer edge shape of the first top surface 11A is rectangular. This rectangle can be a rectangle having long sides and short sides. The long side direction of the first top surface 11A and the long side direction of the outer edge shape of the base 11 are parallel. Note that when viewed from above, the outer edge shape of the first top surface 11A does not have to be rectangular.

[0034] In a top view, the first top surface 11A is surrounded by the second top surface 11C. The second top surface 11C is an annular surface that surrounds the first top surface 11A in a top view. The second top surface 11C is a rectangular annular surface. Here, the frame defined by the inner edge of the second top surface 11C is referred to as the inner frame of the second top surface 11C, and the frame defined by the outer edge of the second top surface 11C is referred to as the outer frame of the second top surface 11C.

[0035] The base 11 has a recess surrounded by a frame by the second top surface 11C. The recess defines a portion of the base 11 that is recessed below the second top surface 11C. The first top surface 11A is a part of the recess. One or more inner surfaces 11E are also a part of the recess. The second top surface 11C is located above the first top surface 11A.

[0036] The base 11 has one or more step portions 11F. The step portion 11F has an upper surface 11G and a side surface 11H that intersects with the upper surface 11G and extends downward from the upper surface 11G. Here, one step portion 11F has only one upper surface 11G and one side surface 11H. The upper surface 11G intersects with the inner surface 11E. The side surface 11H intersects with the first upper surface 11A.

[0037] One or each step portion 11F is provided inside the inner frame of the second upper surface 11C in top view. One or each step portion 11F is formed along part or all of the inner surface 11E in top view. In the base 11, the side surface 11H is an inner surface, but the side surface 11H and the inner surface 11E are different surfaces. One or each inner surface 11E and one or each side surface 11H are perpendicular to the first upper surface 11A. Here, the perpendicular allows for a difference of ±3 degrees.

[0038] The one or more step portions 11F may include a first step portion 11F1 and a second step portion 11F2. The first step portion 11F1 and the second step portion 11F2 are provided at positions where their respective side surfaces 11H face each other. The first step portion 11F1 and the second step portion 11F2 are provided on the short side of the inner frame of the second upper surface 11C.

[0039] The base 11 has a base portion 11M and a frame portion 11N. The base portion 11M and the frame portion 11N may be made of different materials. The base 11 may be configured to include a base member corresponding to the base portion 11M and a frame member corresponding to the frame portion 11N.

[0040] The base portion 11M includes a first upper surface 11A. The frame portion 11N includes a second upper surface 11C. The frame portion 11N includes one or more outer surfaces 11D and one or more inner surfaces 11E. The frame portion 11N includes one or more step portions 11F.

[0041] The lower surface of the base 11M constitutes a part or all of the area of ​​the lower surface 11B of the base 11. When the lower surface of the base 11M constitutes a part of the area of ​​the lower surface 11B of the base 11, the lower surface of the frame 11N constitutes the remaining area of ​​the lower surface 11B of the base 11.

[0042] The base 11 has a plurality of wiring portions 12A. The plurality of wiring portions 12A include one or more first wiring portions 12A1 disposed in the internal space of the package 10 and one or more second wiring portions 12A2 provided on the outer surface of the package 10.

[0043] One or each first wiring portion 12A1 is provided on the upper surface 11G of the stepped portion 11F. The base 11 has one or more first wiring portions 12A1 provided on the upper surface 11G of the first stepped portion 11F1. The base 11 has one or more first wiring portions 12A1 provided on the upper surface 11G of the second stepped portion 11F2.

[0044] One or each second wiring portion 12A2 is provided on the lower surface 11B of package 10. One or each second wiring portion 12A2 is provided on the lower surface 11B of frame portion 11N. Note that second wiring portion 12A2 may be provided on an outer surface of package 10 that is different from lower surface 11B.

[0045] When viewed from above, the base 11 has one or more second wiring portions 12A2 provided on the lower surface 11B of the base 11 in the region that includes the upper surface 11G of the first step portion 11F1 when the base 11 is divided into two regions by a virtual line that passes through the side surface 11H of the first step portion 11F1 and is parallel to this side surface 11H.

[0046] When viewed from above, the base 11 has one or more second wiring portions 12A2 provided on the lower surface 11B of the base 11 in the region that includes the upper surface 11G of the second step portion 11F2 when the base 11 is divided into two regions by a virtual line that passes through the side surface 11H of the second step portion 11F2 and is parallel to this side surface 11H.

[0047] In the base 11, one or each of the first wiring portions 12A1 is electrically connected to a second wiring portion 12A2. One or more of the first wiring portions 12A1 are electrically connected to different second wiring portions 12A2.

[0048] The base 11 has a bonding pattern 13A. The bonding pattern 13A is provided on the second upper surface 11C. The bonding pattern 13A is provided in a ring shape. The bonding pattern 13A is provided in a rectangular ring shape. In a top view, the first upper surface 11A is surrounded by the bonding pattern 13A.

[0049] The base 11 can be formed, for example, using ceramic as the main material. Examples of the ceramic that can be the main material of the base 11 include aluminum nitride, silicon nitride, aluminum oxide, and silicon carbide.

[0050] Here, the term "main material" refers to the material that accounts for the largest proportion of the mass or volume of the target structure. Note that when the target structure is formed from a single material, that material is the main material. In other words, when a material is the main material, it includes the possibility that the proportion of that material can be 100%.

[0051] The base 11 may be formed using a base member and a frame member formed using different main materials. The base member may be formed using, for example, a material with excellent heat dissipation properties, such as a metal or a metal-containing composite, graphite, or diamond, as its main material. Examples of metals that serve as the main material of the base member include copper, aluminum, or iron. Examples of metal-containing composites that serve as the main material of the base member include copper-molybdenum and copper-tungsten. The frame member may be formed using, for example, the ceramics listed above as the main material of the base 11 as its main material.

[0052] The wiring portion 12A can be formed, for example, using a metal material as the main material. Examples of the metal material that can be the main material of the wiring portion 12A include elemental metals such as Cu, Ag, Ni, Au, Ti, Pt, Pd, Cr, and W, or alloys containing these metals. The wiring portion 12A can be configured, for example, with one or more metal layers.

[0053] The bonding pattern 13A can be formed, for example, using a metal material as the main material. Examples of the metal material that can be the main material of the bonding pattern 13A include elemental metals such as Cu, Ag, Ni, Au, Sn, Ti, and Pd, or alloys containing these metals. The bonding pattern 13A can be formed, for example, by one or more metal layers.

[0054] The lid 14 has an upper surface 14A and a lower surface 14B. The lid 14 also has one or more side surfaces 14C. The lid 14 is configured in the shape of a rectangular parallelepiped flat plate. However, the shape of the lid 14 does not have to be rectangular.

[0055] The lid 14 is bonded to the base 11. The lower surface 14B of the lid 14 is bonded to the second upper surface 11C of the base 11. The lid 14 is bonded to the bonding pattern 13A of the base 11. The lid 14 is bonded to the base 11 via an adhesive.

[0056] The lid 14 has a translucent property that allows light to pass through. Here, translucency means that the transmittance of light incident on the lid 14 is 80% or more. Note that the lid 14 may have a non-translucent region (a region that does not have translucency) in part.

[0057] The lid 14 can be formed, for example, using glass as the main material, or can be formed, for example, using sapphire as the main material.

[0058] (Semiconductor laser element 20) The semiconductor laser element 20 has an upper surface 21A, a lower surface 21B, and a plurality of side surfaces 21C. The shape of the upper surface 21A is a rectangle having long sides and short sides. The outer shape of the semiconductor laser element 20 when viewed from above is a rectangle having long sides and short sides. However, the shape of the upper surface 21A and the outer shape of the semiconductor laser element 20 when viewed from above are not limited to this.

[0059] The semiconductor laser element 20 has a light emitting surface 22 that emits light. For example, the side surface 21C can serve as the light emitting surface 22. The side surface 21C that serves as the light emitting surface 22 intersects with a short side of the top surface 21A. Alternatively, for example, the top surface 21A can serve as the light emitting surface 22.

[0060] A single-emitter semiconductor laser element having one emitter can be used as the semiconductor laser element 20. Alternatively, a multi-emitter semiconductor laser element having multiple emitters can be used as the semiconductor laser element 20.

[0061] For example, a semiconductor laser element that emits blue light can be used as the semiconductor laser element 20. Alternatively, for example, a semiconductor laser element that emits green light can be used as the semiconductor laser element 20. Alternatively, for example, a semiconductor laser element that emits red light can be used as the semiconductor laser element 20. Note that a semiconductor laser element that emits light of another color or wavelength may also be used as the semiconductor laser element 20.

[0062] Here, blue light refers to light whose peak emission wavelength is in the range of 420 nm to 494 nm, green light refers to light whose peak emission wavelength is in the range of 495 nm to 570 nm, and red light refers to light whose peak emission wavelength is in the range of 605 nm to 750 nm.

[0063] The semiconductor laser element 20 emitting blue light or the semiconductor laser element 20 emitting green light may be a semiconductor laser element containing a nitride semiconductor. Examples of nitride semiconductors that can be used include GaN-based semiconductors such as GaN, InGaN, and AlGaN. The semiconductor laser element 20 emitting red light may be a semiconductor laser element containing InAlGaP-based, GaInP-based, or GaAs-based semiconductors such as GaAs and AlGaAs.

[0064] The semiconductor laser element 20 emits directional laser light. Diverging light with a spreading property is emitted from a light emitting surface 22 (emitting end surface) of the semiconductor laser element 20. The light emitted from the semiconductor laser element 20 forms an elliptical far-field pattern (hereinafter referred to as "FFP") in a plane parallel to the light emitting surface 22. The FFP refers to the shape and light intensity distribution of the emitted light at a position away from the light emitting surface of the semiconductor laser element.

[0065] Here, the light passing through the center of the elliptical shape of the FFP, in other words, the light with the peak intensity in the light intensity distribution of the FFP, is referred to as the light traveling along the optical axis or the light passing through the optical axis. ２ The light having the above intensity is called the main part of the light.

[0066] The FFP of light emitted from the semiconductor laser element 20 has an elliptical shape in a plane parallel to the light emitting surface 22, with the stacking direction being longer than the direction perpendicular to the stacking direction. The stacking direction is the direction in which multiple semiconductor layers including the active layer are stacked in the semiconductor laser element 20. The direction perpendicular to the stacking direction can also be referred to as the in-plane direction of the semiconductor layers. The long axis direction of the elliptical shape of the FFP can also be referred to as the fast axis direction of the semiconductor laser element 20, and the short axis direction can also be referred to as the slow axis direction of the semiconductor laser element 20.

[0067] Based on the light intensity distribution of FFP, 1 / e of the peak intensity ２ The angle at which light with an intensity of 1 / e of the peak intensity spreads is defined as the light spread angle of the semiconductor laser element 20. Here, the light spread angle is the angle at which light with a peak intensity (light passing through the optical axis) spreads. ２ The spread angle of light is expressed as the angle formed by the light with an intensity of 1 / e of the peak intensity. ２ In the description of this specification, when simply referring to the "angle of light", it is assumed that the angle is 1 / e of the peak intensity. ２ This refers to the angle of spread of light at an intensity of

[0068] The divergence angle of the light emitted from the semiconductor laser element 20 in the fast axis direction can be equal to or greater than 20 degrees and less than 40 degrees. The divergence angle of this light in the slow axis direction can be greater than 0 degrees and less than 10 degrees. The divergence angle of this light in the fast axis direction is larger than the divergence angle of the light in the slow axis direction.

[0069] For example, the divergence angle in the fast axis direction of blue light emitted from the semiconductor laser element 20 can be 20 degrees or more and less than 30 degrees, and the divergence angle in the slow axis direction can be 2.5 degrees or more and less than 7.5 degrees. Alternatively, the divergence angle in the fast axis direction of green light emitted from the semiconductor laser element 20 can be 20 degrees or more and less than 30 degrees, and the divergence angle in the slow axis direction can be 5 degrees or more and less than 10 degrees. Alternatively, the divergence angle in the fast axis direction of red light emitted from the semiconductor laser element 20 can be 30 degrees or more and less than 40 degrees, and the divergence angle in the slow axis direction can be 2.5 degrees or more and less than 7.5 degrees.

[0070] (Submount 30) The submount 30 has an upper surface 31A, a lower surface 31B, and one or more side surfaces 31C. The upper surface 31A can be considered a mounting surface on which other components are mounted. The shape of the upper surface 31A is rectangular. This rectangle of the upper surface 31A can have short sides and long sides. Note that the shape of the upper surface 31A does not have to be rectangular.

[0071] The outer shape of the submount 30 when viewed from above is rectangular. This rectangle of the submount 30 may have short sides and long sides. However, the outer shape of the submount 30 when viewed from above does not have to be rectangular. When viewed from above, the submount 30 may have an outer shape in which the length in one direction (hereinafter, this direction will be referred to as the short side direction of the submount 30) is shorter than the length in the direction perpendicular to this (hereinafter, this direction will be referred to as the long side direction of the submount 30). In the illustrated submount 30, the short side direction is the same as the X direction, and the long side direction is the same as the Y direction.

[0072] The submount 30 may be configured to include a substrate 32A and an upper metal member 32B. The submount 30 may also be configured to include a lower metal member 32C. The upper metal member 32B is provided on the upper surface of the substrate 32A. The lower metal member 32C is provided on the lower surface of the substrate 32A. The submount 30 further includes a wiring layer 33. The wiring layer 33 is provided on the upper metal member 32B.

[0073] The substrate 32A has insulating properties and is made of, for example, silicon nitride, aluminum nitride, or silicon carbide. It is preferable to select ceramic, which has relatively good heat dissipation properties (high thermal conductivity), as the main material of the substrate 32A.

[0074] The upper metal member 32B is primarily made of a metal such as copper or aluminum. The upper metal member 32B has one or more metal layers. The upper metal member 32B may have multiple metal layers made primarily of different metals.

[0075] The lower metal member 32C is primarily made of a metal such as copper or aluminum. The lower metal member 32C has one or more metal layers. The lower metal member 32C may have multiple metal layers made primarily of different metals.

[0076] The wiring layer 33 can be formed using a metal. For example, the wiring layer 33 can be formed using AuSn solder (a metal layer of AuSn).

[0077] For example, the length of the submount 30 in the short side or lateral direction is 700 μm or more and 1400 μm or less. The length of the submount 30 in the long side or longitudinal direction is 1200 μm or more and 2700 μm or less. The difference between the length of the submount 30 in the longitudinal direction and the length of the submount 30 in the lateral direction is 100 μm or more and 2000 μm or less.

[0078] For example, the thickness of the submount 30 (width in the direction perpendicular to the upper surface 31A) is 200 μm or more and 400 μm or less. Also, for example, the thickness of the substrate 32A is 100 μm or more and 300 μm or less. Also, for example, the thickness of the upper metal member 32B is 25 μm or more and 75 μm or less. Also, for example, the thickness of the lower metal member 32C is 25 μm or more and 75 μm or less. Also, for example, the thickness of the wiring layer 33 is 1 μm or more and 5 μm or less.

[0079] (Reflecting member 40) The reflecting member 40 has a lower surface 41A and a light-reflecting surface 41B that reflects light. The light-reflecting surface 41B is inclined with respect to the lower surface 41A. A line connecting the lower end and upper end of the light-reflecting surface 41B is inclined with respect to the lower surface 41A. The angle at which the light-reflecting surface 41B is inclined with respect to the lower surface 41A is referred to as the inclination angle of the light-reflecting surface 41B.

[0080] The light reflecting surface 41B is a flat surface. However, the light reflecting surface 41B may be a curved surface. The inclination angle of the light reflecting surface 41B is 45 degrees. However, the inclination angle of the light reflecting surface 41B does not have to be 45 degrees.

[0081] Here, the first reflecting member 40A and the second reflecting member 40B, both of which are part of the reflecting member 40, will be described.

[0082] The first reflecting member 40A and the second reflecting member 40B have different polarization conversion performances for light of a predetermined wavelength. Here, polarization conversion performance refers to the ability to change the polarization direction of light, and is a concept that also includes the ability to maintain the polarization direction unchanged. For example, even if the first reflecting member 40A reflects light without changing its polarization direction and the second reflecting member 40B reflects light by changing its polarization direction, it can be said that the polarization conversion performances of the first reflecting member 40A and the second reflecting member 40B are different.

[0083] Examples of components that change the polarization direction of light include half-wave plates and quarter-wave plates. A half-wave plate is a wave plate that outputs light by giving a phase difference of λ / 2 between two perpendicularly polarized components of incident light. A quarter-wave plate is a wave plate that outputs light by giving a phase difference of λ / 4 between two perpendicularly polarized components of incident light. Wave plates can also be called polarization conversion components.

[0084] When light of a predetermined wavelength and having the same wavelength and polarization direction is incident on the first reflecting member 40A and the second reflecting member 40B, the polarization direction of the light reflected by the light reflecting surface 41B of the first reflecting member 40A and emitted from the first reflecting member 40A is different from the polarization direction of the light reflected by the light reflecting surface 41B of the second reflecting member 40B and emitted from the second reflecting member 40B.

[0085] For example, the first reflecting member 40A and the second reflecting member 40B can have different polarization conversion performances for light of a predetermined wavelength by having wave plates with different polarization conversion performances. Also, for example, the first reflecting member 40A and the second reflecting member 40B can have different polarization conversion performances for light of a predetermined wavelength by having one reflecting member 40 with a wave plate and the other reflecting member 40 without a wave plate.

[0086] The second reflecting member 40B has a wave plate 42 provided on the light reflecting surface 41B. The wave plate 42 has a first surface 42A and a second surface 42B opposite to the first surface 42A. The second surface 42B is located between the first surface 42A and the light reflecting surface 41B.

[0087] The first reflecting member 40A does not have a wave plate provided on the light reflecting surface 41B. The shape of the first reflecting member 40A is the same as the shape of the second reflecting member 40B excluding the wave plate 42. The shape of the second reflecting member 40B is larger than the shape of the first reflecting member 40A because it has the wave plate 42.

[0088] The thickness from the first surface 42A to the second surface 42B of the wave plate 42 is 5 μm or less. This thickness can also be 1 μm or more. However, this thickness may be 2 μm or less. This makes it possible to reduce the difference in size between the first reflecting member 40A and the second reflecting member 40B.

[0089] The second reflecting member 40B may exhibit differences in reflectance and polarization conversion performance depending on the angle of incidence of light incident on the first surface 42A of the wave plate 42. Assuming that light is incident at a large angle of incidence, such as an angle of incidence of 50 degrees or more on the first surface 42A, the second reflecting member 40B maintains a certain level of reflectance and polarization conversion performance over a wide range of incident angles.

[0090] The second reflecting member 40B maintains polarization conversion performance for light in a predetermined wavelength range at a rate of 85% or more when the angle of incidence of light incident on the first surface 42A is between 20 and 70 degrees (hereinafter, this condition will be referred to as the "first condition"). Alternatively, the second reflecting member 40B maintains polarization conversion performance for light in this predetermined wavelength range at a rate of 90% or more when the angle of incidence is within this range (hereinafter, this condition will be referred to as the "second condition"). Alternatively, the second reflecting member 40B maintains polarization conversion performance for light in this predetermined wavelength range at a rate of 95% or more when the angle of incidence is within this range (hereinafter, this condition will be referred to as the "third condition").

[0091] Here, the maintenance rate of polarization conversion performance refers to the ratio of the amount of light [W] of light emitted after the desired polarization conversion to the amount of light [W] of incident light. For example, a polarizer is used to cause only light of a specific polarization to be incident on the second reflecting member 40B, and another polarizer is used to measure the amount of light of the desired polarization among the light emitted from the second reflecting member 40B. The maintenance rate of polarization conversion performance can be measured from this measurement value and the measurement value of the amount of light of the specific polarization incident on the second reflecting member 40B. In a configuration in which a wave plate is provided on the light reflecting surface of the specific polarization, the reflectivity of the light reflecting surface is theoretically equal to or greater than the maintenance rate of polarization conversion performance.

[0092] Furthermore, light that has undergone the desired polarization conversion is, for example, light that has been given a phase difference of λ / 4 with respect to the incident light if it passes through a quarter-wave plate once, light that has been given a phase difference of λ / 2 with respect to the incident light if it passes through a half-wave plate once, and light that has been given a phase difference of λ / 2 with respect to the incident light if it passes through a quarter-wave plate twice. In a configuration in which a wave plate is provided on a light-reflecting surface, it is considered that light passes through the wave plate twice in total, once when it enters the light-reflecting surface and once when it is reflected by the light-reflecting surface and exits.

[0093] It is preferable that second reflecting member 40B maintains polarization conversion performance for light in a predetermined wavelength range by 85% or more when the angle of incidence of light incident on first surface 42A is in the range of 15 to 75 degrees (hereinafter, this condition will be referred to as the "fourth condition"), or it is preferable that second reflecting member 40B maintains polarization conversion performance for light in this predetermined wavelength range by 90% or more within this range of incidence angle (hereinafter, this condition will be referred to as the "fifth condition").

[0094] As the range of the incident angle of light incident on the wave plate 42 increases, the reflectivity and polarization conversion performance characteristics for each wavelength of light may change in response to changes in the incident angle of the light. For example, the wavelength of light at which the reflectivity is maximized (the reflectivity peak wavelength) may also change in response to changes in the incident angle. Therefore, if the wavelength range that satisfies the condition for the maintenance rate of the polarization conversion performance described above can be narrowed, the second reflecting member 40B is easier to manufacture.

[0095] In the second reflecting member 40B, the wavelength range of light that satisfies each of the first to fifth conditions for the maintenance rate of the polarization conversion performance described above (the "predetermined wavelength range" in the conditions) may be at least 10 nm or more. Alternatively, this predetermined wavelength range is preferably at least 20 nm or more.

[0096] Furthermore, the wavelength range of light that satisfies the first condition does not need to be 50 nm or more. In other words, second reflecting member 40B may satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range not exceeding 50 nm, but may not satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range exceeding 50 nm.

[0097] Furthermore, the wavelength range of light that satisfies the second condition does not have to be 40 nm or more. In other words, second reflecting member 40B may satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range not exceeding 40 nm, but may not satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range exceeding 40 nm.

[0098] Furthermore, the wavelength range of light that satisfies the third condition does not have to be 30 nm or more. In other words, second reflecting member 40B may satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range not exceeding 30 nm, but may not satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range exceeding 30 nm.

[0099] Furthermore, the wavelength range of light that satisfies the fourth condition does not have to be 40 nm or more. In other words, second reflecting member 40B may satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range not exceeding 40 nm, but may not satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range exceeding 40 nm.

[0100] Furthermore, the wavelength range of light that satisfies the fifth condition does not have to be 30 nm or more. In other words, second reflecting member 40B may satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range not exceeding 30 nm, but may not satisfy the condition for the maintenance rate of polarization conversion performance in a wavelength range exceeding 30 nm.

[0101] The second reflecting member 40B only needs to satisfy any one of the first to fifth conditions described above when the polarization of light incident on the light-reflecting surface 41B is either p-polarized or s-polarized. In other words, the second reflecting member 40B may satisfy the conditions for both p-polarized incident light and s-polarized incident light, or may be a second reflecting member 40B that satisfies the conditions only for either p-polarized incident light or s-polarized incident light.

[0102] For example, the second reflecting member 40B satisfies at least any one of the first to fifth conditions described above for p-polarized light incident on the light-reflecting surface 41B. Note that it is preferable that the second reflecting member 40B satisfies the conditions for both p-polarized light and s-polarized light.

[0103] In a predetermined wavelength range in which the second reflecting member 40B satisfies at least any one of the first to fifth conditions, the maximum reflectance of light on the light-reflecting surface 41B of the first reflecting member 40A is greater than the maximum maintenance rate of the polarization conversion performance of the second reflecting member 40B. This reflectance is greater than this maintenance rate by 1% or more. Alternatively, this reflectance can be greater than this maintenance rate by 2% or more. Furthermore, this reflectance can be greater than this maintenance rate by 3% or more.

[0104] The reflecting member 40 can be primarily made of glass, metal, or the like. It is preferable to use a heat-resistant material as the primary material of the reflecting member 40. The primary material can be, for example, glass such as quartz or BK7 (borosilicate glass), or metal such as Al. The reflecting member 40 can also be formed using Si as the primary material.

[0105] If the main material is a reflective material such as Al, the light reflecting surface 41B can be formed from the main material. Instead of forming the light reflecting surface 41B from the main material, the general shape of the reflecting member 40 may be formed from the main material, and the light reflecting surface 41B may be formed on the surface of the general shape. In this case, the light reflecting surface 41B may be formed from a metal layer such as Ag or Al, or a Ta layer, for example. ２ O ５ / SiO ２ , TiO ２ / SiO ２ , Nb ２ O ５ / SiO ２ The illustrated reflecting member 40 has a reflecting film made of a dielectric multilayer film provided on the surface of a general shape formed from a main material, and a light reflecting surface 41B is formed.

[0106] The light reflecting surface 41B has a reflectance of 90% or more for the peak wavelength of light irradiated onto the light reflecting surface 41B. This reflectance may also be 95% or more. This reflectance can also be 99% or more. The light reflectance is 100% or less or less than 100%.

[0107] (Protection Element 50) The protection element 50 has an upper surface 51A, a lower surface 51B, and one or more side surfaces 51C. The shape of the protection element 50 is a rectangular parallelepiped. However, the shape of the protection element 50 does not have to be a rectangular parallelepiped.

[0108] The protective element 50 is intended to prevent a specific element (e.g., a semiconductor laser element) from being destroyed by excessive current flowing through it. An example of the protective element 50 is a Zener diode. The Zener diode may be made of Si.

[0109] (Wiring 60) The wiring 60 is a linear conductive material with joints at both ends. The joints at both ends become joints with other components. The wiring 60 is used for electrical connection between two components. The wiring 60 is, for example, a metal wire. Examples of metals that can be used include gold, aluminum, silver, and copper.

[0110] (Optical member 70) The optical member 70 has an upper surface 71A, a lower surface 71B, and one or more side surfaces 71C. The optical member 70 imparts an optical effect to light incident on the optical member 70. Examples of optical effects imparted to light by the optical member 70 include light collection, collimation, diffusion, polarization, diffraction, wave combination, light guidance, reflection, and wavelength conversion.

[0111] The optical member 70 has an optically active surface that provides an optical effect. The upper surface 71A, the lower surface 71B, or the side surface 71C can be the optically active surface. Alternatively, the optically active surface may be located at a position different from the upper surface 71A, the lower surface 71B, or the side surface 71C. For example, the optically active surface may be formed inside the optical member 70 rather than on the surface thereof.

[0112] The optical element 70 may have one or more lens surfaces 71D. The lens surfaces 71D are optically active surfaces of the optical element 70. Note that the optical element 70 having the lens surfaces 71D may also be called a lens element. The optical element 70 applies an optical effect of focusing, diffusing, or collimating to light that passes through the lens surfaces 71D and is emitted from the optical element 70. For example, the optical element 70 is a collimating lens that converts light that enters the optical element 70 into collimated light and emits it.

[0113] One or each lens surface 71D is provided on the upper surface 71A side. Alternatively, lens surface 71D may be provided on the lower surface 71B side. Upper surface 71A and lower surface 71B are flat surfaces. One or each lens surface 71D intersects with upper surface 71A. In a top view, one or each lens surface 71D is surrounded by upper surface 71A.

[0114] When viewed from above, the outer shape of the optical member 70 is rectangular. However, the outer shape of the optical member 70 when viewed from above does not have to be rectangular. The lower surface 71B is flat. No lens surface 71D is formed on the lower surface 71B side of the optical member 70. The shape of the lower surface 71B is rectangular. However, the shape of the lower surface 71B does not have to be rectangular.

[0115] In optical member 70, the portion overlapping with lens surface 71D in top view is referred to as lens portion 72A. In optical member 70, the portion overlapping with top surface 71A in top view is referred to as non-lens portion 72B. Bottom surface 71B has a region that forms the bottom surface of one or each lens portion 72A and a region that forms the bottom surface of non-lens portion 72B.

[0116] The optical member 70 may have a plurality of lens surfaces 71D formed in a line. The direction in which the plurality of lens surfaces 71D are aligned in a top view is referred to as the lens connection direction. In the illustrated optical member 70, the connection direction is the same as the X direction.

[0117] The plurality of lens surfaces 71D are formed so that the vertices of the lens surfaces 71D are aligned on a straight line. This imaginary line connecting the vertices is parallel to the lower surface 71B of the optical member 70. Note that "parallel" here includes a difference of ±5 degrees or less.

[0118] The curvature of two or more of the lens surfaces 71D may be the same for some or all of the lens surfaces 71D. All of the lens surfaces 71D may have the same curvature.

[0119] The optical member 70 is translucent. The optical member 70 has a transmittance of 80% or more for the peak wavelength of light incident on the optical member 70. The optical member 70 may have a translucent region and a non-translucent region (hereinafter referred to as a non-translucent region). In the non-translucent region, the transmittance for the peak wavelength of light incident on the optical member 70 is 50% or less. The optical member 70 can be formed using glass such as BK7, for example.

[0120] Next, the light emitting device 1 will be described.

[0121] (Light Emitting Device 1) In the light emitting device 1, a plurality of semiconductor laser elements 20 are arranged in the internal space of the package 10. By arranging the semiconductor laser elements 20 in a sealed space, it is possible to suppress a decrease in light output due to dust collection.

[0122] The plurality of semiconductor laser elements 20 are arranged on the first upper surface 11A. The plurality of semiconductor laser elements 20 are arranged side by side in one direction. Here, the direction in which the plurality of semiconductor laser elements 20 are arranged is referred to as the first direction. In the illustrated light-emitting device 1, the first direction is a direction parallel to the X direction.

[0123] The light-emitting surfaces 22 of the semiconductor laser elements 20 are aligned in a second direction, which is perpendicular to the first direction in a top view. The semiconductor laser elements 20 may be offset in the second direction, but the offset in the second direction is preferably 30 μm or less. If the offset in the second direction is large, the light-emitting device 1 will become larger in size in the second direction.

[0124] Each of the multiple semiconductor laser elements 20 emits light in the second direction. The optical axes of the light emitted from each semiconductor laser element 20 are parallel to each other. In each semiconductor laser element 20, the optical axis of the light emitted from the light emitting surface 22 is parallel to the second direction. In the illustrated light emitting device 1, the second direction is a direction parallel to the Y direction.

[0125] In one or each semiconductor laser element 20, the fast axis direction of light emitted from light emitting surface 22 is parallel to the direction perpendicular to first upper surface 11A. In one or each semiconductor laser element 20, the slow axis direction of light emitted from light emitting surface 22 is parallel to the first direction. In the illustrated light emitting device 1, this fast axis direction is the same as the Z direction, and this slow axis direction is the same as the X direction.

[0126] Here, when distinguishing between the light beams emitted from the individual semiconductor laser elements 20, the light beam emitted from one semiconductor laser element 20 is referred to as a partial beam. The light beams emitted from the multiple semiconductor laser elements 20 are composed of multiple partial beams.

[0127] The fast axis directions of the partial light beams emitted from the respective semiconductor laser elements 20 are parallel to each other. The slow axis directions of the partial light beams emitted from the respective semiconductor laser elements 20 are parallel to each other. The plurality of semiconductor laser elements 20 emit a plurality of partial light beams having elliptical FFPs aligned in the first direction.

[0128] Each semiconductor laser element 20 emits light having the same divergence angle in the fast axis direction. Here, "same" includes a difference of ±5 degrees. Each semiconductor laser element 20 emits light having the same divergence angle in the slow axis direction. Here, "same" includes a difference of ±3 degrees. A plurality of partial beams each having the same divergence angle are emitted from the plurality of semiconductor laser elements 20. The plurality of semiconductor laser elements 20 may include two or more semiconductor laser elements 20 having different divergence angles.

[0129] Each semiconductor laser element 20 emits light beams having the same polarization direction. Each semiconductor laser element 20 emits light beams in TE mode from the light emitting surface 22. Alternatively, each semiconductor laser element 20 emits light beams in TM mode from the light emitting surface 22.

[0130] The emission peak wavelengths of all of the semiconductor laser elements 20 are within ±20 nm of the first wavelength. Alternatively, the emission peak wavelengths of all of the semiconductor laser elements 20 are within ±10 nm of the first wavelength. In other words, the semiconductor laser elements 20 are selected so that the difference in emission peak wavelengths among the semiconductor laser elements 20 falls within a wavelength range of at most 20 nm.

[0131] The plurality of semiconductor laser elements 20 may include two semiconductor laser elements 20 having a difference in emission peak wavelength of 3 nm or more and 8 nm or less. The plurality of semiconductor laser elements 20 may include a semiconductor laser element 20 having an emission peak wavelength of a first wavelength, a semiconductor laser element 20 having an emission peak wavelength that is 2 nm or more and 8 nm or less than the first wavelength, and a semiconductor laser element 20 having an emission peak wavelength that is 2 nm or more and 8 nm or less than the first wavelength. By multiplexing the emission peak wavelengths in a close range, speckle noise can be reduced.

[0132] In the light-emitting device 1, the multiple semiconductor laser elements 20 are mounted on one or multiple submounts 30. Each semiconductor laser element 20 may be mounted on a different submount 30. Two or more semiconductor laser elements 20 may be mounted on one submount 30. The semiconductor laser elements 20 are disposed on the first upper surface 11A via the submount 30. By interposing the submount 30, the height from the first upper surface 11A to the light emission point of the semiconductor laser element 20 can be adjusted.

[0133] The plurality of semiconductor laser elements 20 have the same height from the first upper surface 11A to the light emission point. Note that "same" here includes a deviation in the height from the first upper surface 11A to the light emission point of 30 μm or less. In the illustrated light-emitting device 1, the height direction is the same as the Z direction.

[0134] In the light emitting device 1, a plurality of reflective members 40 are disposed in the internal space of the package 10. The plurality of reflective members 40 are disposed on the first upper surface 11A. The plurality of reflective members 40 are disposed side by side in the first direction.

[0135] The multiple reflecting members 40 include one or more first reflecting members 40A and one or more second reflecting members 40B. The number of first reflecting members 40A included in the light emitting device 1 is the same as or one more than the number of second reflecting members 40B included in the light emitting device 1. Because the light reflectivity of the light reflecting surface 41B of the first reflecting member 40A is greater than the maintenance rate of the polarization conversion performance of the second reflecting member 40B, the amount of light emitted from the light emitting device 1 is greater when the number of first reflecting members 40A is greater than the number of second reflecting members 40B, rather than when the number is less than the number of first reflecting members 40B. Note that the number of first reflecting members 40A included in the light emitting device 1 may be one less than the number of second reflecting members 40B included in the light emitting device 1.

[0136] The light reflecting surfaces 41B of the plurality of reflecting members 40 are aligned in the second direction in top view. Here, "aligned" includes a deviation of 50 μm or less in the second direction among the plurality of reflecting members 40. By suppressing deviations in the height of the light emission points and deviations in the second direction among the light reflecting surfaces 41B, it is possible to arrange the points at which light traveling along the optical axis is irradiated on the light reflecting surfaces 41B among the partial lights in a straight line in top view.

[0137] Light emitted from the plurality of semiconductor laser elements 20 is reflected by the light reflecting surfaces 41B of the plurality of reflecting members 40. One or more partial lights are reflected by one light reflecting surface 41B. With respect to at least the main portion of the light, the plurality of partial lights are irradiated onto the light reflecting surfaces 41B of the reflecting members 40 that are different from each other. With respect to at least the main portion of the light, each partial light is irradiated onto the light reflecting surfaces 41B of the reflecting members 40 that are different from each other. There may be a one-to-one relationship between the light reflecting surfaces 41B and the partial lights.

[0138] The plurality of semiconductor laser elements 20 include one or more first semiconductor laser elements 20A corresponding to one or more first reflecting members 40A, and one or more second semiconductor laser elements 20B corresponding to one or more second reflecting members 40B. The first semiconductor laser element 20A and the second semiconductor laser element 20B may have different divergence angles.

[0139] Light emitted from one or more first semiconductor laser elements 20A is reflected by light reflecting surfaces 41B of one or more first reflecting members 40A. Light emitted from one or more second semiconductor laser elements 20B is reflected by light reflecting surfaces 41B of one or more second reflecting members 40B.

[0140] Light emitted from one or more second semiconductor laser elements 20B is incident on the first surface 42A of the wave plate 42 of one or more second reflecting members 40B, reflected by the light reflecting surface 41B of the wave plate 42 of one or more second reflecting members 40B, and emitted from the first surface 42A of the wave plate 42 of the wave plate 42 of one or more second reflecting members 40B.

[0141] The polarization direction of light incident on the light reflecting surface 41B of the multiple reflecting members 40 is the same. P-polarized light is incident on the wave plate 42 of the second reflecting member 40B. Note that s-polarized light may be incident on the wave plate 42 of the second reflecting member 40B. For example, each semiconductor laser element 20 emits TM mode light in the second direction from the light emitting surface 22.

[0142] When light having the same polarization direction is incident on multiple reflecting members 40, the polarization direction of the light emitted from the first reflecting member 40A is different from that of the light emitted from the second reflecting member 40B. Note that even when light having different polarization directions is incident on multiple reflecting members 40, the polarization direction of the light emitted from the first reflecting member 40A may be different from that of the light emitted from the second reflecting member 40B.

[0143] When the wave plate 42 is a quarter wave plate, if light of the same polarization direction is incident on the first reflecting member 40A and the second reflecting member 40B, the phase difference between the light emitted from the first reflecting member 40A and the light emitted from the second reflecting member 40B is λ / 2. When p-polarized light is incident on the reflecting member 40, the light emitted from the second reflecting member 40B becomes s-polarized.

[0144] When the light emitting device 1 emits light composed of multiple partial lights whose emission peak wavelengths fall within a range of 20 nm, the inclusion of both p-polarized and s-polarized partial lights contributes to reducing speckle noise. Furthermore, by providing a wave plate 42 on the light reflecting surface 41B of the reflecting member 40, the light emitting device can be made smaller.

[0145] Divergent light emitted from the plurality of semiconductor laser elements 20 is irradiated onto the light reflecting surfaces 41B of the plurality of reflecting members 40. By irradiating the light reflecting surface 41B with the divergent light emitted from the light emitting surface 22 as it is, it is possible to realize a light emitting device 1 in which no optical member for controlling light is disposed between the semiconductor laser elements 20 and the reflecting member 40, which contributes to the miniaturization of the light emitting device. Light passing through the optical axis emitted from the plurality of semiconductor laser elements 20 is incident on the light reflecting surfaces 41B of the plurality of reflecting members 40 at an incident angle of 45 degrees.

[0146] The light reflecting surfaces 41B of the respective reflecting members 40 are irradiated with the main portions of the light emitted from the mutually different semiconductor laser elements 20. The light emitted from the respective semiconductor laser elements 20 and traveling along the optical axis is irradiated with the light reflecting surfaces 41B of the mutually different reflecting members 40.

[0147] The maintenance rate of the polarization conversion performance of second reflecting member 40B is maximized at the angle of incidence at which light traveling along the optical axis emitted from second semiconductor laser element 20B is incident on first surface 42A. In the illustrated light-emitting device 1, the maintenance rate of the polarization conversion performance is maximized when the angle of incidence of light incident on first surface 42A is 45 degrees.

[0148] Here, a cross-sectional view taken along a virtual plane that passes through the optical axis of light emitted from the semiconductor laser element 20 and is perpendicular to the first upper surface 11A is referred to as an optical axis cross-sectional view. In addition, in the optical axis cross-sectional view, the angle of incidence with respect to the wave plate 42 when the light travels on a straight line connecting the emission point of the light on the light emission surface 22 of the second semiconductor laser element 20B and the lower end point of the first surface 42A of the second reflecting member 40B is referred to as a lower limit incident angle θ1. In addition, in the optical axis cross-sectional view, the angle of incidence with respect to the wave plate 42 when the light travels on a straight line connecting the emission point of the light on the light emission surface 22 of the second semiconductor laser element 20B and the upper end point of the first surface 42A of the second reflecting member 40B is referred to as an upper limit incident angle θ2 (see FIG. 10 ).

[0149] In the light emitting device 1, the second semiconductor laser element 20B and the second reflecting member 40B are arranged so that the upper limit incident angle θ2 is 70 degrees or more. Alternatively, the second semiconductor laser element 20B and the second reflecting member 40B are arranged so that the upper limit incident angle θ2 is 75 degrees or more. This allows light that travels upward from the optical axis from the second semiconductor laser element 20B and whose angle of incidence with the first surface 42A is equal to or smaller than the upper limit incident angle θ2 to be incident on the wave plate 42.

[0150] Theoretically, the smaller the distance between the light emitting surface 22 of the second semiconductor laser element 20B and the first surface 42A of the wave plate 42, the larger the upper limit incident angle θ2. On the other hand, if the light emitting surface 22 is too close to the first surface 42A, the second semiconductor laser element 20B will overlap the first surface 42A in a top view, which may interfere with the light emitted from the second reflecting member 40B. Taking this into consideration, it is preferable that the second semiconductor laser element 20B and the second reflecting member 40B are arranged so that the upper limit incident angle θ2 is 80 degrees or less.

[0151] In relation to the second reflecting member 40B that satisfies at least any one of the first to third conditions, the upper limit of the incident angle θ2 is preferably 70 degrees or more and 80 degrees or less. In relation to the second reflecting member 40B that satisfies at least any one of the fourth and fifth conditions, the upper limit of the incident angle θ2 is preferably 75 degrees or more and 80 degrees or less.

[0152] In one or more second semiconductor laser elements 20B and one or more second reflecting members 40B, the corresponding second semiconductor laser elements 20B and second reflecting members 40B can satisfy the condition for the above-mentioned upper limit incident angle θ2.

[0153] Even when divergent light is incident on the second reflecting member 40B, the desired emission light can be effectively emitted from the light emitting device 1 by adjusting the range of the incident angle of the light through the arrangement of the second semiconductor laser element 20B and the second reflecting member 40B, taking into account the incidence angle dependency of the polarization conversion performance of the wavelength plate 42.

[0154] In addition, by considering the expected range of the incident angle of light incident on the reflecting member 40, specifying the angle range of the incident angle at which sufficient polarization conversion performance can be obtained in the wave plate 42, and then correspondingly not widening the wavelength range of light at which sufficient polarization conversion performance can be obtained, the wave plate 42 can be efficiently manufactured. If an attempt is made to obtain sufficient polarization conversion performance over a wide wavelength range, the thickness from the first surface 42A to the second surface 42B of the wave plate 42 may become large.

[0155] When the first reflecting member 40A and the second reflecting member 40B are arranged side by side in the first direction, it may be necessary to provide a minimum gap between the semiconductor laser element 20 and the reflecting member 40. In this case, the gap between the first reflecting member 40A and the semiconductor laser element 20 is larger than that between the first reflecting member 40A and the semiconductor laser element 20, and the light emitting device 1 becomes larger in size when the wave plate 42 is thicker.

[0156] Furthermore, when the height of the light emission point is the same, the greater the thickness of wave plate 42, the greater the difference between the range of incident angles of light incident on light reflecting surface 41B and the range of incident angles of light incident on first surface 42A of wave plate 42. In order to efficiently reflect appropriately polarization-converted light from light reflecting surface 41B, it is preferable that the thickness of wave plate 42 is small.

[0157] The divergence angle in the fast axis direction of the light emitted from second semiconductor laser element 20B is preferably smaller than the upper limit incident angle θ2 minus the incident angle at which light passing through the optical axis is incident on wave plate 42. By satisfying such a relationship between the divergence angle and the upper limit incident angle θ2, it is possible to efficiently emit polarization-converted light from second reflecting member 40B.

[0158] In the light-emitting device 1, the divergence angle in the fast axis direction of the light emitted from the second semiconductor laser element 20B may be greater than the value obtained by subtracting the incident angle at which light passing through the optical axis is incident on the wave plate 42 from the upper limit incident angle θ2. In this case, a major portion of the light is not irradiated onto the wave plate 42, and therefore, if the difference between the divergence angle in the fast axis direction and the value obtained by subtracting the incident angle at which light passing through the optical axis is incident on the wave plate 42 from the upper limit incident angle θ2 becomes too large, the amount of light that is polarization-converted and emitted decreases. Therefore, in one or more second reflecting members 40B, it is preferable that the intensity of the portion of the light irradiated onto the light reflecting surface 41B, which is the light irradiated onto the upper end of the light reflecting surface 41B, is 15% or less of the peak intensity.

[0159] In the light emitting device 1, the multiple reflective members 40 are arranged side by side such that the second reflective member 40B is not arranged between the first reflective members 40A and 40A, and the first reflective member 40A is not arranged between the second reflective members 40B and 40B.

[0160] No second reflecting member 40B is disposed between an imaginary line passing through one of the ends of one or more first reflecting members 40A and parallel to the second direction and an imaginary line passing through the other end and parallel to the second direction. Furthermore, no first reflecting member 40A is disposed between an imaginary line passing through one of the ends of one or more second reflecting members 40B and parallel to the second direction and an imaginary line passing through the other end and parallel to the second direction.

[0161] In the light emitting device 1, one or more protection elements 50 are disposed in the internal space of the package 10. One or each protection element 50 is mounted on the submount 30. One protection element 50 protects one or more semiconductor laser elements 20.

[0162] In the light emitting device 1, a plurality of wirings 60 are provided for electrical connection. The plurality of wirings 60 includes two or more wirings 60 for electrically connecting the plurality of semiconductor laser elements 20 to the package 10. The plurality of wirings 60 includes one or more wirings 60 for electrically connecting one or more protection elements 50 to the plurality of semiconductor laser elements 20. By providing the plurality of wirings 60, the plurality of semiconductor laser elements 20 are electrically connected to the first wiring portion 12A1 and the second wiring portion 12A2.

[0163] The plurality of semiconductor laser elements 20 are electrically connected in series. A current path is formed that flows from the first wiring portion 12A1 provided in the first step portion 11F1, through the plurality of semiconductor laser elements 20, to the first wiring portion 12A1 provided in the second step portion 11F2. Alternatively, a current path is formed that flows from the first wiring portion 12A1 provided in the second step portion 11F2, through the plurality of semiconductor laser elements 20, to the first wiring portion 12A1 provided in the first step portion 11F1.

[0164] The light emitted from the plurality of semiconductor laser elements 20 is reflected by the plurality of reflecting members 40 and emitted upward from the upper surface 14A. The polarization direction of the light emitted from one or more first semiconductor laser elements 20A and emitted from the upper surface 14A is different from the polarization direction of the light emitted from one or more second semiconductor laser elements 20B and emitted from the upper surface 14A.

[0165] Of the light emitted from the top surface 14A, one or more partial beams of light emitted from one or more first semiconductor laser elements 20A, reflected by one or more first reflecting members 40A, and then emitted from the top surface 14A have a polarization ratio of 10 or greater. This polarization ratio can be measured, for example, by emitting light from only one or more first semiconductor laser elements 20A among the multiple semiconductor laser elements 20. Alternatively, for example, the polarization ratio can be measured by emitting light from multiple semiconductor laser elements 20 and placing a light-shielding member on the optical path of the light emitted from one or more second semiconductor laser elements 20B. The polarization ratio here indicates the ratio of p-polarized light to s-polarized light, and whether p-polarized light or s-polarized light is used as the denominator depends on the polarization direction of the incident light. Either p-polarized light or s-polarized light with a polarization ratio value of 1 or greater is used as the denominator.

[0166] The polarization ratio of the light emitted from the upper surface 14A is 5 or less. Preferably, this polarization ratio is 3 or less, and more preferably, this polarization ratio is 2 or less. This light includes a plurality of partial beams emitted from one or more first semiconductor laser elements 20A and one or more second semiconductor laser elements 20B. The polarization ratio here employs the same denominator as the polarization ratio of the one or more partial beams emitted from the one or more first semiconductor laser elements 20A described above.

[0167] In the light emitting device 1, the optical member 70 is fixed to the package 10. The optical member 70 is bonded to the lid 14 and fixed to the package 10. Light emitted from the plurality of semiconductor laser elements 20 and emitted from the package 10 is incident on the optical member 70. The light incident on the optical member 70 is given an optical effect by the optical action surface and is then emitted from the optical member 70.

[0168] The optical member 70 has a plurality of lens surfaces 71D corresponding to the respective semiconductor laser elements 20. A main portion of light emitted from one semiconductor laser element 20 and reflected by the reflecting member 40 passes through one lens surface 71D. The partial light that has passed through each lens surface becomes collimated light and is emitted from the optical member 70. A plurality of partial light beams, each collimated, are emitted from the light emitting device 1 aligned in the first direction.

[0169] Second Embodiment A light emitting device 2 according to a second embodiment will now be described. FIGS. 1 to 4 and 7A to 16B are diagrams illustrating an exemplary embodiment of the light emitting device 2. FIG. 1 is a perspective view of the light emitting device 2. FIG. 2 is a side view of the light emitting device 2. FIG. 3 is a cross-sectional view of the light emitting device 2 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the light emitting device 2. FIG. 16A is a top view showing components disposed in the internal space of the package 10 of the light emitting device 2. Note that the wiring 60 is not shown in FIG. 16A. FIG. 16B is a top view illustrating light emitted from the light emitting device 2. Note that hatching indicates the shape of the light emitted from the light emitting device 2. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently. FIG. 7A is a side view of a first reflecting member 40A. FIG. 7B is a side view of a second reflecting member 40B. FIG. 8 is a top view showing components arranged on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view for explaining the lower limit incident angle θ1 and the upper limit incident angle θ2 with respect to the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-sectional line in FIG. 11. FIG. 13 is a top view of the base 11. FIG. 14 is a bottom view of the base 11. FIG. 15 is a cross-sectional view of the base 11 taken along the XV-XV cross-sectional line in FIG. 13.

[0170] Of the above-described descriptions of the light-emitting device 1 and each component of the first embodiment, all of the descriptions except for those that may be considered inconsistent with the drawings of the light-emitting device 2 in Figures 1 to 4 and 7A to 16B also apply to the description of the light-emitting device 2. To avoid redundancy, all of the descriptions that are not inconsistent will not be repeated here.

[0171] (Light-emitting device 2) In light-emitting device 2, the plurality of reflecting members 40 include first reflecting members 40A and second reflecting members 40B arranged between the first reflecting members 40A. The plurality of reflecting members 40 also include first reflecting members 40A arranged between second reflecting members 40B and second reflecting members 40B. The plurality of reflecting members 40 are arranged such that the first reflecting members 40A and the second reflecting members 40B are alternately arranged. This arrangement also makes it possible to reduce speckle noise.

[0172] Furthermore, by arranging the first reflecting members 40A and the second reflecting members 40B alternately, a single mechanism for reducing speckle noise can be completed by the adjacent first reflecting members 40A and second reflecting members 40B. Therefore, one or more speckle noise reduction units each made up of adjacent first reflecting members 40A and second reflecting members 40B can be arranged, enabling optical control on a unit-by-unit basis.

[0173] Third Embodiment A light emitting device 3 according to a third embodiment will now be described. FIGS. 1 to 15, 17A, and 17B are diagrams illustrating an exemplary embodiment of the light emitting device 3. FIG. 1 is a perspective view of a light emitting device 1 as a component included in the light emitting device 3. FIG. 2 is a side view of the light emitting device 1. FIG. 3 is a cross-sectional view of the light emitting device 1 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the light emitting device 1. FIG. 5 is a top view showing components disposed in the internal space of the package 10 of the light emitting device 1. Note that the wiring 60 is not shown in FIG. 5. FIG. 6 is a top view illustrating light emitted from the light emitting device 1. Note that hatching indicates the shape of the light emitted from the light emitting device 1. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently. FIG. 7A is a side view of a first reflecting member 40A. FIG. 7B is a side view of a second reflecting member 40B. FIG. 8 is a top view showing components arranged on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view illustrating the lower limit incident angle θ1 and the upper limit incident angle θ2 for the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-section line in FIG. 11. FIG. 13 is a top view of the base 11. FIG. 14 is a bottom view of the base 11. FIG. 15 is a cross-sectional view of the base 11 taken along the XV-XV cross-section line in FIG. 13. FIG. 17A is a side view of the light emitting device 3. FIG. 17B is a top view illustrating light emitted from the light emitting device 3. Note that hatching indicates the shape of the light emitted from the light emitting device 3. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently.

[0174] Of the above-mentioned descriptions of the light emitting device 1 of the first embodiment, the light emitting device 2 of the second embodiment, and each of the components, all of the contents except for those that may be considered to be inconsistent with the drawings of the light emitting device 3 in Figures 1 to 15, 17A, and 17B also apply to the description of the light emitting device 3. To avoid redundancy, all of the non-inconsistent contents will not be repeated here.

[0175] (Partial polarization conversion member 80) The partial polarization conversion member 80 has a polarization conversion region 81. The polarization direction of light incident on the polarization conversion region 81 is converted and the light is emitted from the partial polarization conversion member 80. The polarization conversion region 81 can be formed by providing a wavelength plate.

[0176] (Light-emitting device 3) The light-emitting device 3 is a light-emitting device including the light-emitting device 1 of the first embodiment and a partial polarization conversion member 80.

[0177] In the light emitting device 3, a partial polarization conversion member 80 is provided on the optical path of the light emitted from the optical member 70. The light emitted from the plurality of semiconductor laser elements 20 is incident on the partial polarization conversion member 80.

[0178] For each partial light, a part of the partial light enters the polarization conversion region 81, and the rest does not enter the polarization conversion region 81. For each partial light, it is preferable that 50%±5% of the partial light enters the polarization conversion region 81. As a result, the partial light emitted from one semiconductor laser element 20 contains first light and second light having different polarization directions, which is expected to reduce speckle noise.

[0179] The partial polarization conversion member 80 may transmit incident light and emit it, or may reflect incident light and emit it. When transmitting light, a half-wave plate can be used as the wave plate forming the polarization conversion region 81. When reflecting light, a quarter-wave plate can be used as the wave plate forming the polarization conversion region 81. This allows the polarization conversion region 81 to convert p-polarized light to s-polarized light or s-polarized light to p-polarized light and emit the light.

[0180] Fourth Embodiment A light emitting device 4 according to a fourth embodiment will be described. FIGS. 1 to 4, 7A to 16B, 18A, and 18B are diagrams illustrating an exemplary embodiment of the light emitting device 4. FIG. 1 is a perspective view of a light emitting device 2 as a component of the light emitting device 4. FIG. 2 is a side view of the light emitting device 2. FIG. 3 is a cross-sectional view of the light emitting device 2 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the light emitting device 2. FIG. 16A is a top view showing components disposed in the internal space of the package 10 of the light emitting device 2. Note that the wiring 60 is not shown in FIG. 16A. FIG. 16B is a top view illustrating light emitted from the light emitting device 2. Note that hatching indicates the shape of the light emitted from the light emitting device 2. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently. FIG. 7A is a side view of a first reflecting member 40A. FIG. 7B is a side view of the second reflecting member 40B. FIG. 8 is a top view showing components arranged on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view illustrating the lower limit incident angle θ1 and the upper limit incident angle θ2 for the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-section line in FIG. 11. FIG. 13 is a top view of the base 11. FIG. 14 is a bottom view of the base 11. FIG. 15 is a cross-sectional view of the base 11 taken along the XV-XV cross-section line in FIG. 13. FIG. 18A is a side view of the light emitting device 4. FIG. 18B is a top view illustrating light emitted from the light emitting device 4. Note that hatching indicates the shape of the light emitted from the light emitting device 4. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently.

[0181] Of the above-mentioned descriptions of the light emitting device 1 of the first embodiment, the light emitting device 2 of the second embodiment, the light emitting device 3 of the third embodiment, and their respective components, all of the descriptions except for those that may be considered inconsistent with the drawings of the light emitting device 4 in Figures 1 to 4, 7A to 16B, 18A, and 18B also apply to the description of the light emitting device 4. To avoid redundancy, all of the descriptions that do not contradict each other will not be repeated here.

[0182] The light emitting device 4 differs from the light emitting device 3 in that the light emitting device 1 of the first embodiment included in the light emitting device 3 of the third embodiment is replaced with the light emitting device 2 of the second embodiment. There are no other differences, and therefore the light emitting device 4 can be explained using the explanations of the first to third embodiments already given.

[0183] Fifth Embodiment A light emitting device 5 according to a fifth embodiment will be described. FIGS. 1 to 5, 7A to 15, and 19 are drawings for explaining an exemplary embodiment of the light emitting device 5. FIG. 1 is a perspective view of the light emitting device 5. FIG. 2 is a side view of the light emitting device 5. FIG. 3 is a cross-sectional view of the light emitting device 5 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the light emitting device 5. FIG. 5 is a top view showing components disposed in the internal space of the package 10 of the light emitting device 5. Note that the wiring 60 is not shown in FIG. 19. FIG. 19 is a top view illustrating light emitted from the light emitting device 5. Note that hatching indicates the shape of the light emitted from the light emitting device 5. Furthermore, L1 and L2 indicate light having different polarization directions, and are hatched differently. FIG. 7A is a side view of a first reflecting member 40A. FIG. 7B is a side view of a second reflecting member 40B. FIG. 8 is a top view showing components arranged on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view for explaining the lower limit incident angle θ1 and the upper limit incident angle θ2 with respect to the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-sectional line in FIG. 11. FIG. 13 is a top view of the base 11. FIG. 14 is a bottom view of the base 11. FIG. 15 is a cross-sectional view of the base 11 taken along the XV-XV cross-sectional line in FIG. 13.

[0184] Of the above-mentioned descriptions of the light-emitting device 1 and each component of the first embodiment, all of the descriptions except for those that can be said to be inconsistent with the drawings of the light-emitting device 5 in Figures 1 to 5, 7A to 15, and 19, and those that contradict the following description of the light-emitting device 5, also apply to the description of the light-emitting device 5. To avoid redundancy, all of the descriptions that do not contradict will not be repeated here.

[0185] (Light-emitting device 5) In light-emitting device 5, the first semiconductor laser element 20A and the second semiconductor laser element 20B emit light beams having different polarization directions. The first semiconductor laser element 20A emits light beams in TE mode, and the second semiconductor laser element 20B emits light beams in TM mode. Alternatively, the first semiconductor laser element 20A emits light beams in TM mode, and the second semiconductor laser element 20B emits light beams in TE mode.

[0186] The first semiconductor laser element 20A and the second semiconductor laser element 20B emit light of different colors. The difference between the peak emission wavelength of the light emitted from the first semiconductor laser element 20A and the peak emission wavelength of the light emitted from the second semiconductor laser element 20B is 30 nm or more. Alternatively, this difference can be 50 nm or more. Alternatively, this difference can be 70 nm or more.

[0187] In the light-emitting device 5, the multiple semiconductor laser elements 20 include one or more semiconductor laser elements 20 that emit red light, one or more semiconductor laser elements 20 that emit green light, and one or more semiconductor laser elements 20 that emit blue light.

[0188] Furthermore, the polarization direction of the red light emitted from the semiconductor laser element 20 is different from the polarization direction of the green light emitted from the semiconductor laser element 20, and is also different from the polarization direction of the blue light emitted from the semiconductor laser element 20. On the other hand, the polarization direction of the green light emitted from the semiconductor laser element 20 is the same as the polarization direction of the blue light emitted from the semiconductor laser element 20.

[0189] In the light emitting device 5, light beams with different polarization directions emitted from the plurality of semiconductor laser elements 20 become light beams with the same polarization direction and are emitted from the plurality of reflecting members 40. By making partial light beams with different polarization directions incident on the first reflecting member 40A and the second reflecting member 40B, light beams with the same polarization direction are emitted. It is sometimes desirable for the polarization directions to be aligned for optical control, and the light emitting device 5 can emit light beams with aligned polarization directions.

[0190] For example, the plurality of semiconductor laser elements 20 include one or more first semiconductor laser elements 20A that emit red light, one or more second semiconductor laser elements 20B that emit green light, and one or more second semiconductor laser elements 20B that emit blue light.

[0191] Among the plurality of semiconductor laser elements 20, the divergence angle in the fast axis direction of the semiconductor laser element 20 emitting red light is larger than the divergence angle in the fast axis direction of the semiconductor laser element 20 emitting green light, and is also larger than the divergence angle in the fast axis direction of the semiconductor laser element 20 emitting blue light. Since the range of the incident angle of light incident on the wave plate 42 is larger for light with a larger divergence angle, light loss can be reduced by making the light with a smaller divergence angle incident on the wave plate 42.

[0192] For example, the plurality of semiconductor laser elements 20 include one or more second semiconductor laser elements 20B that emit red light, one or more first semiconductor laser elements 20A that emit green light, and one or more first semiconductor laser elements 20A that emit blue light.

[0193] When divergent light is incident on the wave plate 42, it is preferable that the wavelength range of light incident on one or more second reflecting members 40B is narrow in order to maintain polarization conversion performance over a wide range of incident angles. When the difference between the emission peak wavelength of the semiconductor laser element 20 emitting blue light and the emission peak wavelength of the semiconductor laser element 20 emitting green light is 50 nm or more, it is easier to manufacture the wave plate 42 by making the red light incident on the second reflecting member 40B and making the green light and blue light incident on the first reflecting member 40A, respectively. Alternatively, there is no need to prepare separate wave plates 42 for green light and blue light, which is advantageous in terms of productivity.

[0194] Sixth Embodiment A light-emitting module 901 according to a sixth embodiment will be described. FIGS. 1 to 4, 7A to 15, and 20 to 24 are drawings for explaining an exemplary embodiment of the light-emitting module 901. FIG. 20 is a perspective view of the light-emitting module 901. Note that the X, Y, and Z directions in FIG. 20 are aligned with the X, Y, and Z directions of the first light-emitting device 6 but not aligned with the X, Y, and Z directions of the second light-emitting device 7. FIG. 1 is a perspective view of the first light-emitting device 6 and the second light-emitting device 7. FIG. 2 is a side view of the first light-emitting device 6 and the second light-emitting device 7. FIG. 3 is a cross-sectional view of the first light-emitting device 6 and the second light-emitting device 7 taken along the line III-III in FIG. 1. FIG. 4 is a perspective view showing components disposed in the internal space of the package 10 of the first light-emitting device 6 and the second light-emitting device 7. FIG. 21 is a top view showing components disposed in the internal space of the package 10 of the first light-emitting device 6. FIG. 22 is a top view for explaining light emitted from the first light-emitting device 6. FIG. 23 is a top view showing components arranged in the internal space of the package 10 of the second light-emitting device 7. FIG. 24 is a top view illustrating light emitted from the second light-emitting device 7. Note that the wiring 60 is omitted from FIGS. 21 and 23. Hatching in FIGS. 22 and 24 indicates the shape of light emitted from the light-emitting device 1. L1 and L2 indicate light with different polarization directions, and are hatched differently. FIG. 7A is a side view of the first reflecting member 40A. FIG. 7B is a side view of the second reflecting member 40B. FIG. 8 is a top view showing components arranged on the submount 30. FIG. 9 is a side view showing components arranged on the submount 30. FIG. 10 is a schematic side view illustrating the lower limit incident angle θ1 and the upper limit incident angle θ2 for the second reflecting member 40B. FIG. 11 is a perspective view of the package 10. FIG. 12 is a cross-sectional view of the package 10 taken along the XII-XII cross-sectional line in FIG. 11. Fig. 13 is a top view of the base body 11. Fig. 14 is a bottom view of the base body 11. Fig. 15 is a cross-sectional view of the base body 11 taken along the line XV-XV in Fig. 13 .

[0195] Of the above-mentioned descriptions of the light emitting device 1 of the first embodiment to the light emitting device 5 of the fifth embodiment and their respective components, all of the descriptions except for those that can be said to be inconsistent with the drawings of the light emitting module 901 in Figures 1 to 4, 7A to 15, and 20 to 24, and those that contradict the following description of the light emitting module 901, also apply to the description of the light emitting module 901. To avoid redundancy, all of the descriptions that do not contradict will not be repeated here.

[0196] The light-emitting module 901 includes a plurality of components, including a first light-emitting device 6, a second light-emitting device 7, a wiring board 101, a connector 201, and a thermistor 301. Note that the light-emitting module 901 may include other components, and may not include some of the components listed here.

[0197] The first light-emitting device 6 includes a plurality of components, including a package 10, one or more first semiconductor laser elements 20A, one or more submounts 30, one or more first reflecting members 40A, one or more protection elements 50, a plurality of wirings 60, and an optical member 70.

[0198] The second light-emitting device 7 includes a plurality of components, including a package 10, one or more second semiconductor laser elements 20B, one or more submounts 30, one or more second reflecting members 40B, one or more protection elements 50, a plurality of wirings 60, and an optical member 70.

[0199] (Light-emitting module 901) In the light-emitting module 901, a first light-emitting device 6 and a second light-emitting device 7 are mounted on a wiring substrate 101. The first light-emitting device 6 includes one or more first semiconductor laser elements 20A and a first reflecting member 40A, and the second light-emitting device 7 includes one or more second semiconductor laser elements 20B and a second reflecting member 40B.

[0200] Even with such a configuration of the light emitting module 901, it is possible to achieve the same effects as the light emitting devices of the first to fifth embodiments. Furthermore, by preparing a light emitting device including the first reflecting member 40A and a light emitting device including the second reflecting member 40B in units of light emitting devices, it is possible to flexibly respond to various provision forms, such as a light emitting module that mixes these, a light emitting module that does not mix these, and a light emitting device alone, as needed.

[0201] Although the above describes various embodiments of the present invention, the light-emitting device and light-emitting module according to the present invention are not strictly limited to the light-emitting device or light-emitting module of each embodiment. In other words, the present invention can be realized without being limited to the external shape and structure of the light-emitting device or light-emitting module disclosed in each embodiment. The present invention can be applied without necessarily including all components. For example, if the claims do not recite some of the components of a light-emitting device or light-emitting module disclosed in an embodiment, the claims allow for the design freedom of those components by those skilled in the art, such as substitution, omission, modification of shape, or change of material, and specify that the invention described in the claims applies.

[0202] Through the contents described so far in this specification, the following technical matters are disclosed. a plurality of semiconductor laser elements, the plurality of semiconductor laser elements being arranged in an internal space of the package, each having an emission peak wavelength within ±20 nm of a first wavelength; and a plurality of reflecting members, the plurality of semiconductor laser elements being arranged in the internal space of the package, the plurality of reflecting members including one or more first reflecting members having a first light reflecting surface, and one or more second reflecting members having a second light reflecting surface and a wave plate provided on the second light reflecting surface, wherein the plurality of semiconductor laser elements include one or more first semiconductor laser elements and one or more second semiconductor laser elements, wherein light emitted from the one or more first semiconductor laser elements is reflected by the first light reflecting surface of the one or more first reflecting members, and light emitted from the one or more second semiconductor laser elements is reflected by the second light reflecting surface of the one or more second reflecting members, the polarization directions of the light incident on the first light reflecting surface and the light incident on the second light reflecting surface are the same, and the polarization directions of the light emitted from the first reflecting member and the second reflecting member are different. (Item 2) The light emitting device according to item 1, wherein the one or more first reflecting members do not have a wave plate provided on the first light reflecting surface, and the wave plate provided on the second light reflecting surface of the one or more second reflecting members is a quarter wave plate. (Item 3) The light emitting device according to item 1 or 2, wherein the multiple reflecting members are arranged side by side in a first direction, and the multiple semiconductor laser elements each emit light in a direction perpendicular to the first direction in a top view. (Item 4) The light emitting device according to any one of items 1 to 3, wherein a thickness of the wave plate in a direction perpendicular to the second light reflecting surface is 5 μm or less. (Item 5) The light emitting device according to any one of items 1 to 4, wherein the multiple reflecting members are arranged side by side in the first direction so that the first reflecting members and the second reflecting members are arranged alternately. (Item 6) The light emitting device according to any one of items 1 to 5, wherein each of the plurality of semiconductor laser elements emits divergent light from a light emitting surface, and the plurality of reflecting members are irradiated with the divergent light emitted from each of the plurality of semiconductor laser elements.(Item 7) The light emitting device according to item 6, wherein each of the plurality of semiconductor laser elements emits divergent light having a divergence angle of 40 degrees or less in the fast axis direction. (Item 8) The light emitting device according to any one of items 1 to 7, wherein in the one or more second reflecting members, a portion of the light irradiated onto the second light reflecting surface, the partial light irradiated onto an upper end of the second light reflecting surface, has an intensity of 15% or less of a peak intensity. (Item 9) A light emitting module comprising: a substrate; a first light emitting device mounted on the substrate, the first package including: one or more first semiconductor laser elements disposed in an internal space of the first package, the first semiconductor laser elements having an emission peak wavelength within a first wavelength ±20 nm; and one or more first reflecting members disposed in the internal space of the first package and having a first light reflecting surface; and a second light emitting device mounted on the substrate, the second package including: one or more second semiconductor laser elements disposed in the internal space of the second package, the second semiconductor laser elements having an emission peak wavelength within the first wavelength ±20 nm; and one or more second reflecting members disposed in the internal space of the second package, the second light reflecting surface, and a wave plate provided on the second light reflecting surface.

[0203] The light-emitting device and light-emitting module described in the embodiments can be used in a projector. In other words, a projector can be considered one application form to which the present invention can be applied. However, the present invention is not limited to this and can be used in various applications such as illumination, exposure, vehicle headlights, head-mounted displays, and backlights for other displays.

[0204] DESCRIPTION OF SYMBOLS 1, 2, 3, 4, 5, 6, 7 Light emitting device 10 Package 11 Base 11A First upper surface 11B Lower surface 11C Second upper surface 11D Outer surface 11E Inner surface 11F Step portion 11F1 First step portion 11F2 Second step portion 11G Upper surface 11H Side surface 11M Base 11N Frame portion 12A Wiring portion 12A1 First wiring portion 12A2 Second wiring portion 13A Bonding pattern 14 Lid 14A Upper surface 14B Lower surface 14C Side surface 20 Semiconductor laser element 20A First semiconductor laser element 20B Second semiconductor laser element 21A Upper surface 21B Lower surface 21C Side surface 22 Light emitting surface 30 Submount 31A Upper surface 31B Lower surface 31C Side surface 32A Substrate 32B Upper metal member 32C Lower metal member 33 Wiring layer 40 Reflecting member 40A First reflecting member 40B Second reflecting member 41A Lower surface 41B Light reflecting surface 42 Wave plate 42A First surface 42B Second surface 50 Protective element 51A Upper surface 51B Lower surface 51C Side surface 60 Wiring 70 Optical member (lens member) 71A Upper surface 71B Lower surface 71C Side surface 71D Lens surface (optically acting surface) 72A Lens portion 72B Non-lens portion 80 Partial polarization conversion member 81 Polarization conversion region 101 Wiring substrate 201 Connector 301 Thermistor 901 Light emitting module

Claims

1. A light emitting device comprising: a package; a plurality of semiconductor laser elements, each of which has an emission peak wavelength within ±20 nm of a first wavelength; and a plurality of reflecting members, each of which is disposed in the internal space of the package, the plurality of reflecting members including one or more first reflecting members having a first light reflecting surface, and one or more second reflecting members having a second light reflecting surface and a wave plate provided on the second light reflecting surface, wherein the plurality of semiconductor laser elements include one or more first semiconductor laser elements and one or more second semiconductor laser elements, light emitted from the one or more first semiconductor laser elements is reflected by the first light reflecting surface of the one or more first reflecting members, and light emitted from the one or more second semiconductor laser elements is reflected by the second light reflecting surface of the one or more second reflecting members, the polarization directions of the light incident on the first light reflecting surface and the light incident on the second light reflecting surface are the same, and the polarization directions of the light emitted from the first reflecting member and the light emitted from the second reflecting member are different.

2. The light emitting device of claim 1, wherein the one or more first reflecting members do not have a wave plate provided on the first light reflecting surface, and the wave plate provided on the second light reflecting surface of the one or more second reflecting members is a quarter wave plate.

3. The light emitting device according to claim 1 or 2, wherein the plurality of reflective members are arranged in a first direction, and each of the plurality of semiconductor laser elements emits light in a direction perpendicular to the first direction when viewed from above.

4. The light emitting device according to claim 1, wherein the thickness of the wave plate in a direction perpendicular to the second light reflecting surface is 5 μm or less.

5. A light emitting device according to any one of claims 1 to 4, wherein the plurality of reflective members are arranged in the first direction such that the first reflective members and the second reflective members are arranged alternately.

6. A light emitting device according to any one of claims 1 to 5, wherein each of the plurality of semiconductor laser elements emits divergent light from a light emitting surface, and the plurality of reflecting members are irradiated with the divergent light emitted from each of the plurality of semiconductor laser elements.

7. The light emitting device according to claim 6, wherein each of said plurality of semiconductor laser elements emits divergent light having a divergence angle in the fast axis direction of 40 degrees or less.

8. A light emitting device as described in any one of claims 1 to 7, wherein in the one or more second reflecting members, a portion of the light irradiated to the second light reflecting surface, the intensity of the partial light irradiated to the upper end of the second light reflecting surface, is 15% or less of the peak intensity.

9. A light emitting module comprising: a substrate; a first light emitting device mounted on the substrate, the first light emitting device comprising: a first package; one or more first semiconductor laser elements disposed in an internal space of the first package, the first semiconductor laser elements having an emission peak wavelength within a first wavelength ±20 nm; and one or more first reflecting members disposed in the internal space of the first package and having a first light reflecting surface; and a second light emitting device mounted on the substrate, the second light emitting device comprising: a second package; one or more second semiconductor laser elements disposed in the internal space of the second package, the second semiconductor laser elements having an emission peak wavelength within the first wavelength ±20 nm; and one or more second reflecting members disposed in the internal space of the second package, the second light reflecting surface; and a wave plate provided on the second light reflecting surface.

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