Light source device

Abstract

To provide a light source device capable of arranging multiple light emitting points at a narrow pitch.SOLUTION: A light source device includes a support substrate having a top surface, a first light emitting element supported on the top surface, and having a plurality of first light emitting points emitting first light in a predetermined direction intersecting the top surface, and a second light-emitting element provided apart from the first light emitting element in the optical axis direction of the first light and transmitting the first light, and having a plurality of second light-emitting points that emit the second light in a predetermined direction. The optical axis of the first light and the optical axis of the second light do not overlap.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Light source devices including multiple semiconductor light emitting elements can be used in devices such as head-mounted displays, projectors, displays, and lighting fixtures. In such light source devices, it is sometimes necessary to arrange the light emitting points of the multiple semiconductor light emitting elements at a narrow pitch. Patent Document 1 discloses an optical module used in a wavelength division multiplexing (WDM) system in optical communication technology. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-179315 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a light source device that can arrange a plurality of light emitting points at a narrow pitch. [Means for solving the problem]

[0005] In one embodiment, the light source device of the present disclosure comprises a support substrate having an upper surface, a first light-emitting element supported on the upper surface, the first light-emitting element having a plurality of first light-emitting points that emit first light toward a predetermined direction that intersects with the upper surface, and a second light-emitting element that is disposed away from the first light-emitting element in the optical axis direction of the first light, transmits the first light, the second light-emitting element having a plurality of second light-emitting points that emit second light toward the predetermined direction, wherein the optical axis of the first light and the optical axis of the second light do not overlap. [Effects of the Invention]

[0006] According to the present disclosure, a light source device capable of arranging a plurality of light-emitting points at a narrow pitch can be realized. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an exploded perspective view of a light source device according to this embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the light source device shown in FIG. 1 taken along a plane parallel to the XZ plane. [Figure 3A] FIG. 3A is an enlarged perspective view schematically showing three VCSEL elements and three optical members shown in FIG. [Figure 3B] FIG. 3B is a top view schematically showing the third VCSEL element and the third optical member. [Figure 4] FIG. 4 is a side view seen from the −Y direction, schematically illustrating an example of how the first laser light, the second laser light, and the third laser light are emitted from the first VCSEL element, the second VCSEL element, and the third VCSEL element, respectively. [Figure 5A] FIG. 5A is a cross-sectional view parallel to the YZ plane, schematically showing an example of the configuration of a portion of the first VCSEL element. [Figure 5B] FIG. 5B is a top view of the configuration shown in FIG. 5A. [Figure 6] FIG. 6 is a cross-sectional view parallel to the YZ plane, schematically showing an example of the configuration of a portion of the second VCSEL element. [Figure 7] FIG. 7 is a top view schematically showing an example of the wiring configuration of the first VCSEL element. [Figure 8] FIG. 8 is an exploded perspective view showing a schematic configuration of a light source device according to a modified example of this embodiment. [Figure 9] FIG. 9 is a top view schematically showing an example of the wiring configuration of the first VCSEL element in this modification. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, light source devices according to embodiments of the present disclosure will be described with reference to the drawings. Parts that appear in multiple drawings with the same reference numerals indicate the same or equivalent parts.

[0009] Furthermore, the following are examples to embody the technical idea of ​​the present invention, and do not limit the present invention to the following. Furthermore, the descriptions of the dimensions, materials, shapes, relative positions, etc. of the components are intended to be illustrative and not to limit the scope of the present invention. The sizes and positional relationships of the components shown in each drawing may be exaggerated to facilitate understanding.

[0010] Furthermore, in this specification or claims, when a certain element corresponds to multiple elements and each element needs to be distinguished, the element may be prefixed with "first" or "second" to distinguish them. If the subject or perspective distinguished between this specification and the claims is different, the same prefix may not refer to the same object between the specification and the claims. In the following description, elements having substantially the same functions are designated by the same reference numerals, and their descriptions may be omitted. Terms indicating specific directions or positions (e.g., "upper," "lower," "right," "left," and other terms incorporating these terms) may be used. However, these terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relative direction or positional relationship indicated by terms such as "upper" and "lower" in the referenced drawings is the same, the same arrangement as in the referenced drawings may not be used in drawings other than this disclosure, actual products, manufacturing equipment, etc.

[0011] (Embodiment) First, an example of a light source device according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. For reference, the drawings schematically show an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The direction of the X-axis arrow is referred to as the +X direction, and the opposite direction is referred to as the -X direction. When there is no need to distinguish between the ±X directions, they are simply referred to as the X direction. The same applies to the Y-axis and the Z-axis.

[0012] FIG. 1 is an exploded perspective view of a light source device 100 according to this embodiment. The light source device 100 shown in FIG. 1 includes three vertical cavity surface emitting laser (VCSEL) elements, a support substrate 10, a sidewall 60, and a cover 70. The three VCSEL elements are housed in a space defined by the support substrate 10, the sidewall 60, and the cover 70. The thickness direction of the support substrate 10 is parallel to the Z direction. In the present disclosure, the +Z direction is also referred to as "upward" and the -Z direction is also referred to as "downward."

[0013] Fig. 2 is a cross-sectional view parallel to the XZ plane of the light source device 100 shown in Fig. 1. Fig. 2 shows a first VCSEL element 20a, a second VCSEL element 20b, and a third VCSEL element 20c stacked with a gap between them. In this specification, the first VCSEL element 20a, the second VCSEL element 20b, and the third VCSEL element 20c are collectively referred to as the "three VCSEL elements 20," and each of these VCSEL elements is also referred to as an "each VCSEL element 20."

[0014] Each VCSEL element 20 has a generally flat plate structure and includes multiple light-emitting points arranged two-dimensionally. The three VCSEL elements 20 are arranged at intervals along the thickness direction of the flat plate structure and emit laser light of different wavelengths. The cover 70 is translucent, and the laser light emitted from each light-emitting point passes through the cover 70 and is emitted to the outside.

[0015] By independently driving the three VCSEL elements 20, the light source device 100 can emit laser light of one or more of three different wavelengths from the cover 70. From the viewpoint of reliability, it is preferable that the three VCSEL elements 20 are hermetically sealed inside the light source device 100. The advantage of such hermetically sealing increases as the wavelength of the laser light emitted from the three VCSEL elements 20 becomes shorter. This is because as the wavelength of the laser light becomes shorter, dust is more likely to collect in the part from which the laser light is emitted, resulting in a decrease in the output of the laser light. Note that the light source device 100 does not need to include all three VCSEL elements 20; it may include two of them.

[0016] 1 and 2, the support substrate 10 has an upper surface 10s that is perpendicular to the Z direction. On the upper surface 10s, three VCSEL elements 20, a first optical member 30a, a second optical member 30b, and a third optical member 30c, a first spacer 40a, a second spacer 40b, and a first flexible printed circuit (hereinafter referred to as "FPC") 50a, a second FPC 50b, and a third FPC 50c are provided.

[0017] In this specification, the first optical member 30a, the second optical member 30b, and the third optical member 30c are collectively referred to as the "three optical members 30," and each of these optical members is also referred to as "each optical member 30." Similarly, the first FPC 50a, the second FPC 50b, and the third FPC 50c are collectively referred to as the "three FPCs 50," and each of these FPCs is also referred to as "each FPC 50."

[0018] The top surface 10s directly or indirectly supports a stacked structure of three VCSEL elements 20 spaced apart by first spacers 40a and second spacers 40b. The sidewalls 60 are positioned around the top surface 10s supporting the stacked structure and surround the three VCSEL elements 20, three optical members 30, the first spacers 40a, the second spacers 40b, and the three FPCs 50. The cover 70 is bonded to the top surface of the sidewalls 60 and transmits laser light emitted from each of the three VCSEL elements 20.

[0019] 2 includes a first VCSEL element 20a, a second VCSEL element 20b, and a third VCSEL element 20c arranged in this order, spaced apart from one another, from the side closest to the top surface 10s. The light source device 100 further includes a first spacer 40a that maintains the distance between the first VCSEL element 20a and the second VCSEL element 20b, and a second spacer 40b that maintains the distance between the second VCSEL element 20b and the third VCSEL element 20c.

[0020] The first VCSEL element 20a is supported directly or indirectly by the upper surface 10s of the support substrate 10. The first VCSEL element 20a has a plurality of first light-emitting points arranged two-dimensionally, and emits a first laser light from each of the first light-emitting points in the +Z direction. The first VCSEL element 20a oscillates at a first oscillation wavelength.

[0021] The second VCSEL element 20b is spaced apart from the first VCSEL element 20a in the optical axis direction of the first laser light by a first spacer 40a. The second VCSEL element 20b has a plurality of second light-emitting points arranged two-dimensionally, and emits second laser light from each second light-emitting point in the +Z direction. The second VCSEL element 20b oscillates at a second oscillation wavelength. The second VCSEL element 20b transmits the first laser light.

[0022] The third VCSEL element 20c is spaced apart from the second VCSEL element 20b in the optical axis direction of the second laser light by a second spacer 40b. Furthermore, the third VCSEL element 20c is spaced apart from the first VCSEL element 20a in the optical axis direction of the first laser light. The third VCSEL element 20c has a plurality of third light-emitting points arranged two-dimensionally, and each third light-emitting point emits third laser light in the +Z direction. The third VCSEL element 20c oscillates at a third oscillation wavelength. The third VCSEL element 20c transmits the first laser light and the second laser light.

[0023] The plurality of light-emitting points in each VCSEL element 20 are arranged along a first direction and a second direction that intersect with each other. The first direction and the second direction may be orthogonal to each other, as in a square lattice, or may intersect with each other at a 60° angle, as in a triangular lattice. The plurality of light-emitting points in each VCSEL element 20 may be arranged one-dimensionally along the first direction, rather than two-dimensionally.

[0024] The emission direction of each laser beam does not have to be the +Z direction perpendicular to the upper surface 10s as long as it intersects with the upper surface 10s. The angle formed between the emission direction of each laser beam and the normal direction to the upper surface 10s can be, for example, from 0° to 5° or from 0° to 10°.

[0025] The first to third oscillation wavelengths of the three VCSEL elements 20 are different from one another. In this embodiment, the first oscillation wavelength is longer than the second oscillation wavelength, and the second oscillation wavelength is longer than the third oscillation wavelength. The first oscillation wavelength is, for example, a red wavelength, and is in the range of 605 nm to 750 nm, preferably 610 nm to 700 nm. The second oscillation wavelength is, for example, a green wavelength, and is in the range of 495 nm to 570 nm, preferably 510 nm to 550 nm. The third oscillation wavelength is, for example, a blue wavelength, and is in the range of 420 nm to 494 nm, preferably 440 nm to 475 nm. The first to third oscillation wavelengths do not necessarily have to be RGB wavelengths. Depending on the application, two or all three of the first to third oscillation wavelengths may be equal to one another.

[0026] The three VCSEL elements 20 in this embodiment are arranged so that the oscillation wavelength decreases with increasing distance from the top surface 10s, the reason for which will be described later.

[0027] The light source device 100 may include one or more edge-emitting laser elements or one or more LEDs (Light Emitting Diodes) instead of each VCSEL element 20. Anything that can emit light in the +Z direction is sufficient, and in this specification, these laser elements and LEDs, in addition to the VCSEL elements, are also referred to as "light-emitting elements," and light emitted from each light-emitting element is referred to as "nth light" (n is a natural number).

[0028] 2, the light source device 100 further includes a first optical member 30a, a second optical member 30b, and a third optical member 30c. The first optical member 30a is provided between the first VCSEL element 20a and the second VCSEL element 20b. The second optical member 30b is provided between the second VCSEL element 20b and the third VCSEL element 20c. The third optical member 30c is provided on the surface of the third VCSEL element 20c from which the third laser light is emitted. The first optical member 30a, the second optical member 30b, and the third optical member 30c are supported by the first VCSEL element 20a, the second VCSEL element 20b, and the third VCSEL element 20c, respectively. The first spacer 40a prevents the first optical member 30a from contacting the second VCSEL element 20b located above, and the second spacer 40b prevents the second optical member 30b from contacting the third VCSEL element 20c located above.

[0029] The first optical member 30a includes a plurality of first lens portions corresponding to the plurality of first light-emitting points in the first VCSEL element 20a and a first flat plate portion supporting the first lens portions. Similarly, the second optical member 30b includes a plurality of second lens portions corresponding to the plurality of second light-emitting points in the second VCSEL element 20b and a second flat plate portion supporting the second lens portions. Similarly, the third optical member 30c includes a plurality of third lens portions corresponding to the plurality of third light-emitting points in the third VCSEL element 20c and a third flat plate portion supporting the third lens portions. Like the plurality of light-emitting points in each VCSEL element 20, the plurality of lens portions in each optical member 30 may be arranged one-dimensionally or two-dimensionally. The number of lens portions in each optical member 30 may be equal to or less than the number of corresponding light-emitting points. For example, one lens portion may correspond to one light-emitting point, or one lens portion may correspond to four light-emitting points.

[0030] 2, the light source device 100 further includes a first FPC 50a, a second FPC 50b, and a third FPC 50c for supplying power to the first VCSEL element 20a, the second VCSEL element 20b, and the third VCSEL element 20c, respectively. The support substrate 10 has internal wiring, and power supply electrodes are provided on the upper surface 10s of the support substrate 10. The power supply electrodes are electrically connected to an external power supply device via the internal wiring. Each VCSEL element 20 is electrically connected to the power supply electrode provided on the upper surface 10s via the corresponding FPC 50.

[0031] Next, an example of the arrangement of three VCSEL elements 20 and three optical members 30 will be described with reference to Figures 3A and 3B. Figure 3A is an enlarged perspective view schematically showing the three VCSEL elements 20 and three optical members 30 shown in Figure 2. However, in the example shown in Figure 3A, the spacing between the three VCSEL elements 20 has been expanded to make the explanation easier to understand.

[0032] The first optical member 30a shown in FIG. 3A includes 16 first lens portions 32a arranged in four rows and four columns and a first flat plate portion 34a supporting the first lens portions 32a. The row direction is parallel to the X direction, and the column direction is parallel to the Y direction. The 16 first lens portions 32a may be provided directly on the first VCSEL element 20a without the first flat plate portion 34a. The first VCSEL element 20a shown in FIG. 3A includes 16 first light-emitting points located on the optical axes of the 16 first lens portions 32a. The first lens portions 32a reduce the divergence of the first laser light. The first lens portions 32a may be, for example, collimating lenses or focusing lenses. Each first light-emitting point substantially coincides with the focal point of the corresponding first lens portion 32a. The optical axis 20LA1 of the first laser light emitted from each first light-emitting point in the +Z direction substantially coincides with the optical axis of the corresponding first lens portion 32a.

[0033] Similarly, the second optical member 30b shown in FIG. 3A includes 16 second lens portions 32b arranged in 4 rows and 4 columns and a second flat plate portion 34b supporting the 16 second lens portions 32b. The 16 second lens portions 32b may be provided directly on the second VCSEL element 20b without the second flat plate portion 34b. The second lens portions 32b have a configuration similar to that of the first lens portion 32a. The second VCSEL element 20b shown in FIG. 3A includes 16 second light-emitting points located on the optical axes of the 16 second lens portions 32b. Each second light-emitting point substantially coincides with the focal point of the corresponding second lens portion 32b. The optical axis 20LA2 of the second laser light emitted from each second light-emitting point in the +Z direction substantially coincides with the optical axis of the corresponding second lens portion 32b.

[0034] Similarly, the third optical member 30c shown in FIG. 3A includes 16 third lens portions 32c arranged in 4 rows and 4 columns and a third flat plate portion 34c supporting the third lens portions 32c. The 16 third lens portions 32c may be provided directly on the third VCSEL element 20c without the third flat plate portion 34c. The third lens portions 32c have a configuration similar to that of the first lens portion 32a. The third VCSEL element 20c shown in FIG. 3A includes 16 third light-emitting points located on the optical axes of the 16 third lens portions 32c. Each third light-emitting point substantially coincides with the focal point of the corresponding third lens portion 32c. The optical axis 20LA3 of the third laser light emitted from each third light-emitting point in the +Z direction substantially coincides with the optical axis of the corresponding third lens portion 32c.

[0035] In the light source device shown in FIG. 3A, the optical axis 20LA1 of the first laser beam, the optical axis 20LA2 of the second laser beam, and the optical axis 20LA3 of the third laser beam are spaced apart from one another. In other words, the optical axis 20LA1 of the first laser beam, the optical axis 20LA2 of the second laser beam, and the optical axis 20LA3 of the third laser beam do not overlap one another. The optical axis 20LA1 of the first laser beam does not pass through the second lens portion 32b and the third lens portion 32c. The optical axis 20LA2 of the second laser beam does not pass through the third lens portion 32c. The same applies when one lens portion corresponds to multiple light-emitting points.

[0036] In the three VCSEL elements 20 shown in Fig. 3A, the pitches of the first to third light-emitting points in the X direction are equal to one another (this pitch is referred to as px), and the pitches of the first to third light-emitting points in the Y direction are equal to one another (this pitch is referred to as py). In the example shown in Fig. 3A, px = py, but px ≠ py may also be true. In the three optical members 30 shown in Fig. 3A, the pitches of the first to third lens portions 32a to 32c in the X direction are all equal to the above-mentioned px, and the pitches of the first to third lens portions 32a to 32c in the Y direction are all equal to the above-mentioned py.

[0037] The number of the first to third light-emitting points and the first to third lenses is not limited to 16. Furthermore, the first to third light-emitting points may be arranged randomly as long as the optical axis 20LA1 of the first laser beam does not pass through the second lens portion 32b and the third lens portion 32c, and the optical axis 20LA2 of the second laser beam does not pass through the third lens portion 32c.

[0038] Figure 3B is a top view schematically illustrating the third VCSEL element 20c and the third optical member 30c. The solid-line circle in Figure 3B represents the third lens portion 32c. The dashed-line and dash-dotted-line circles in Figure 3B represent the first lens portion 32a and the second lens portion 32b, respectively, which are located on the -Z direction side of the third VCSEL element 20c. The black dots in Figure 3B represent one of the multiple first light-emitting points 22a, one of the multiple second light-emitting points 22b, and one of the multiple third light-emitting points 22c.

[0039] In the light source device shown in Fig. 3B, the first to third lens portions 32a to 32c are positioned apart from one another when viewed from the +Z direction, i.e., in a top view. In other words, the first to third lens portions 32a to 32c do not have portions that overlap with one another in a top view. The first to third light-emitting points 22a to 22c overlap with the principal points of the first to third lens portions 32a to 32c, respectively, in a top view. The first to third light-emitting points 22a to 22c do not overlap with one another in a top view.

[0040] In the example shown in Fig. 3B, the pitch between the first light-emitting point 22a and the second light-emitting point 22b in the top view can be made narrower than the above-mentioned py, and the pitch between the second light-emitting point 22b and the third light-emitting point 22c in the top view can be made narrower than the above-mentioned px. In the example shown in Fig. 3B, the pitch between the first light-emitting point 22a and the second light-emitting point 22b in the top view is half of py, and the pitch between the second light-emitting point 22b and the third light-emitting point 22c in the top view is half of px.

[0041] In the light source device 100 according to this embodiment, the three VCSEL elements 20 are arranged at intervals along the Z direction such that the first to third light-emitting points 22a to 22c do not overlap one another in top view. The pitch between the first light-emitting point 22a and the second light-emitting point 22b and the pitch between the second light-emitting point 22b and the third light-emitting point 22c in top view can be narrower than the pitch between the light-emitting points in each VCSEL element 20. This allows for a more compact light source device. The pitch between the first light-emitting point 22a and the second light-emitting point 22b in top view can be, for example, 10 μm or more and 100 μm or less. The same applies to the pitch between the second light-emitting point 22b and the third light-emitting point 22c in top view.

[0042] When three VCSEL elements 20 are arranged at intervals along the Z direction such that the first to third light-emitting points 22a to 22c overlap one another in a top view, the first laser light passes near the second and third light-emitting points, and the second laser light passes near the third light-emitting point. In contrast, in the light source device 100 according to this embodiment, the first to third light-emitting points 22a to 22c do not overlap one another in a top view. Therefore, the first laser light does not pass near the second and third light-emitting points, and the second laser light does not pass near the third light-emitting point. Therefore, the first laser light is emitted to the outside with the influence of refractive index changes of the electrode pair (described later) corresponding to the second light-emitting point and the electrode pair (described later) corresponding to the third light-emitting point suppressed. Similarly, the second laser light is emitted to the outside with the influence of refractive index changes of the electrode pair (described later) corresponding to the third light-emitting point suppressed.

[0043] Furthermore, in light source device 100 according to this embodiment, the first laser light passes through first lens portion 32a corresponding to first light-emitting point 22a, but does not pass through second lens portion 32b or third lens portion 32c. Also, the second laser light passes through second lens portion 32b corresponding to second light-emitting point 22b, but does not pass through third lens portion 32c. Therefore, the first to third laser light are each emitted to the outside in an appropriately collimated state.

[0044] Next, an example of how laser light is emitted from each of the three VCSEL elements 20 will be described with reference to Fig. 4. Fig. 4 is a side view, viewed from the -Y direction, that schematically illustrates an example of how first laser light 20L1, second laser light 20L2, and third laser light 20L3 are emitted from first VCSEL element 20a, second VCSEL element 20b, and third VCSEL element 20c, respectively. The dashed arrows in Fig. 4 represent first to third laser light 20L1-20L3.

[0045] As shown in Fig. 4, first to third light-emitting points 22a to 22c emit first to third laser beams 20L1 to 20L3, respectively, and first to third lens portions 32a to 32c collimate or focus first to third laser beams 20L1 to 20L3, respectively. In Fig. 4, second laser beam 20L2 is shown overlapping first laser beam 20L1, but second laser beam 20L2 is shifted in the +Y direction relative to first laser beam 20L1.

[0046] In the light source device shown in FIG. 4, the first light-emitting point 22a is closer to the top surface than the bottom surface of the first VCSEL element 20a, and the second light-emitting point 22b and the third light-emitting point 22c are closer to the bottom surface than the top surfaces of the second VCSEL element 20b and the third VCSEL element 20c. The reason for the term "top surface" is that the top surface of each VCSEL element 20 is not necessarily flat and may have a convex shape, as will be described later. When emitting laser light with a long wavelength such as red, the light-emitting point may be designed to be closer to the top surface than the bottom surface of the VCSEL element. In contrast, when emitting laser light with a short wavelength such as green or blue, the light-emitting point may be designed to be closer to the bottom surface than the top surface of the VCSEL element. However, this is not limited to this, and the first light-emitting point 22a may be closer to the bottom surface of the first VCSEL element 20a than to the top surface, and the second light-emitting point 22b and the third light-emitting point 22c may be closer to the top surface of the second VCSEL element 20b and the third VCSEL element 20c than to their bottom surfaces, respectively.

[0047] Next, with reference to FIGS. 5A to 6, partial configuration examples of the first VCSEL element 20a and the second VCSEL element 20b will be described. The third VCSEL element 20c has a configuration similar to that of the second VCSEL element 20b. FIG. 5A is a cross-sectional view parallel to the YZ plane that schematically shows a partial configuration example of the first VCSEL element 20a. FIG. 5B is a top view of the configuration shown in FIG. 5A. The first VCSEL element 20a shown in FIG. 5A has a layered structure in which a semiconductor substrate 201, an n-side reflective film 202, an n-type semiconductor layer 203, an active layer 204, a p-type semiconductor layer 205, and a p-side reflective film 206 are layered in this order. The p-type and n-type conductivity types may be reversed. The semiconductor substrate 201 may be removed. The n-type semiconductor layer 203 has a flat portion and a protrusion protruding from the flat portion in the +Z direction. An active layer 204 is provided on the upper surface of the convex portion of the n-type semiconductor layer 203, a p-type semiconductor layer 205 is provided on the upper surface of the active layer 204, and a p-side reflective film 206 is provided on the upper surface of the p-type semiconductor layer 205 except for the peripheral region. The first VCSEL element 20a includes an insulating layer 207 that covers the upper surface of the flat portion of the n-type semiconductor layer 203 and the side surfaces of the convex portion. However, there is an exposed portion of the upper surface of the flat portion of the n-type semiconductor layer 203 that is not covered by the insulating layer 207. The first VCSEL element 20a includes a p-side electrode 208p electrically connected to the p-type semiconductor layer 205 and an n-side electrode 208n electrically connected to the exposed portion of the n-type semiconductor layer 203. In the example shown in FIG. 5A , the top surface of the first VCSEL element 20a is the surface of the p-side reflective film 206 opposite the surface that contacts the p-type semiconductor layer 205.

[0048] In the light source device shown in FIG. 5B , the p-side reflective film 206, the insulating layer 207, the p-side electrode 208p, and the n-side electrode 208n are exposed in top view. However, the p-side reflective film 206, the insulating layer 207, the p-side electrode 208p, and the n-side electrode 208n may be covered with an insulating film such as SiO2. The p-side electrode 208p includes a ring-shaped portion surrounding the p-side reflective film 206 and a linear portion extending from the ring-shaped portion along the +Y direction in top view. The n-side electrode 208n includes a C-shaped portion surrounding the ring-shaped portion of the p-side electrode 208p and the p-side reflective film 206 and a linear portion extending from the C-shaped portion along the -Y direction in top view. One pair of the p-side electrode 208p and the n-side electrode 208n constitutes one electrode pair 208.

[0049] The n-side reflective film 202 and the p-side reflective film 206 can each be formed from, for example, a DBR (Distributed Bragg Reflector). A DBR has a structure in which multiple high-refractive index layers and multiple low-refractive index layers are alternately stacked. A DBR has a wavelength range of high reflectance called a stop band. The center wavelength and wavelength width of the stop band are determined by the refractive index and thickness of the high-refractive index layers and the refractive index and thickness of the low-refractive index layers. The reflectance in the stop band of a DBR increases with the refractive index difference between the high-refractive index layers and the low-refractive index layers and / or the number of layers stacked.

[0050] The first VCSEL element 20a that emits the first red laser light may be made of at least one selected from the group consisting of InAlGaP-based, GaInP-based, GaAs-based, and AlGaAs-based semiconductor materials, for example. In one first VCSEL element 20a, the semiconductor substrate 201 is made of n-type GaAs, the layered structure of the n-side reflective film 202 (p-side reflective film 206) is made of n-type (p-type) AlGaAs with different composition ratios, the n-type semiconductor layer 203 (p-type semiconductor layer 205) is made of n-type (p-type) AlGaInP, and the active layer 204 is made of GaInP.

[0051] In the example shown in FIG. 5A, a standing wave is formed between the n-side reflective film 202 and the p-side reflective film 206. The wavelength of the standing wave in air is within the stop band of the n-side reflective film 202 and the p-side reflective film 206, and this wavelength is the first oscillation wavelength of the first laser light. An integer multiple of half the first oscillation wavelength is equal to the optical distance between the opposing reflective surfaces of the n-side reflective film 202 and the p-side reflective film 206. The optical distance is calculated by multiplying the distance light actually propagates through a medium by the refractive index of that medium. Current can be injected into the active layer 204 by applying a forward voltage to the p-side electrode 208p and the n-side electrode 208n. This current injection causes a population inversion in the active layer 204, resulting in light amplification by stimulated emission at the first oscillation wavelength, i.e., laser oscillation. The first light-emitting point in the first VCSEL device 20a is located approximately at the center of the active layer 204. As shown in FIG. 5A, the first emission point is located closer to the top surface than to the bottom surface of the first VCSEL element 20a.

[0052] In the first VCSEL device 20a, the reflectance in the stop band of the n-side reflective film 202 is nearly 100%, and the reflectance in the stop band of the p-side reflective film 206 is slightly lower, for example, 98%, than the reflectance of the n-side reflective film 202. As a result, the first laser light having the first oscillation wavelength within both stop bands passes through the p-side reflective film 206 and is emitted in the +Z direction.

[0053] The first VCSEL element 20a includes a plurality of light-emitting structures arranged two-dimensionally, each having the configuration shown in Fig. 5A. The semiconductor substrate 201 in each light-emitting structure is part of a common semiconductor substrate. The same is true for the n-side reflective film 202, n-type semiconductor layer 203, and insulating layer 207 in each light-emitting structure.

[0054] As shown in Fig. 5A, the top surface of the first VCSEL element 20a is not flat. When the first optical member 30a is provided on the first VCSEL element 20a, the first optical member 30a may be directly supported by the p-side reflective film 206. Alternatively, a spacer or a heat dissipation member may be provided between the first VCSEL element 20a and the first optical member 30a. Providing a spacer makes it easier to align the focal point of the first lens portion 32a with the first light-emitting point.

[0055] FIG. 6 is a cross-sectional view parallel to the YZ plane, schematically illustrating an example of the configuration of a portion of the second VCSEL element 20b. The second VCSEL element 20b shown in FIG. 6 has a configuration obtained by inverting the first VCSEL element 20a shown in FIG. 5A, and includes a bonding layer 209, a metal film 210, and a heat dissipation substrate 211. The semiconductor substrate 201 may be removed, or an anti-reflection film may be provided on the semiconductor substrate 201. The bonding layer 209 is electrically connected to the p-side electrode 208p and the n-side electrode 208n, respectively. The metal film 210 is electrically connected to the bonding layer 209. The heat dissipation substrate 211 supports the metal film 210. In this case, the heat dissipation substrate 211 may be provided with internal wiring and external electrodes electrically connected to an external power supply device. The heat dissipation substrate 211 may correspond one-to-one to each light-emitting point, or may correspond to multiple light-emitting points. 6, the top surface of the second VCSEL element 20b is the surface of the semiconductor substrate 201 opposite to the surface in contact with the n-side reflective film 202.

[0056] The second VCSEL element 20b that emits the second green laser light may be formed of at least one semiconductor material selected from the group consisting of GaN, InGaN, and AlGaN. In one second VCSEL element 20b, the semiconductor substrate 201 is formed of GaN, the layered structure of the n-side reflective film 202 is formed of AlInN and GaN, the layered structure of the p-side reflective film 206 is formed of dielectric films such as SiO2 and Nb2O5, the n-type semiconductor layer 203 (p-type semiconductor layer 205) is formed of n-type (p-type) GaN, and the active layer 204 is formed of InGaN.

[0057] In the example shown in FIG. 6, laser oscillation occurs when a forward voltage is applied to the p-side electrode 208p and the n-side electrode 208n, as described with reference to FIG. 5A.

[0058] In the second VCSEL element 20b, the reflectivity of the p-side reflective film 206 is nearly 100% in the stop band, and the reflectivity of the n-side reflective film 202 is slightly lower than that of the p-side reflective film 206 in the stop band, for example, 98%. As a result, the second laser light having a second oscillation wavelength within both stop bands passes through the n-side reflective film 202 and is emitted in the +Z direction. The second light-emitting point in the second VCSEL element 20b is located approximately at the center of the active layer 204. As shown in FIG. 6, the second light-emitting point is located closer to the bottom surface than to the top surface of the second VCSEL element 20b.

[0059] The second VCSEL element 20b, which emits laser light with a short wavelength, is required to have higher heat dissipation properties than the first VCSEL element 20a, which emits laser light with a long wavelength. In the second VCSEL element 20b shown in FIG. 6, heat generated in the active layer 204 is conducted to the heat dissipation substrate 211. By filling the gap between the heat dissipation substrate 211 and the p-side reflective film 206 with a material with high thermal conductivity, the heat generated in the active layer 204 can be efficiently conducted to the heat dissipation substrate 211. If heat dissipation is not a consideration, the second VCSEL element 20b may have the same configuration as the first VCSEL element 20a. Conversely, the first VCSEL element 20a may have the same configuration as the second VCSEL element 20b if heat dissipation is considered.

[0060] Like the first VCSEL element 20a, the second VCSEL element 20b includes a plurality of light-emitting structures arranged two-dimensionally, each having the configuration shown in Fig. 6. The semiconductor substrate 201 in each light-emitting structure is part of a common semiconductor substrate, as are the n-side reflective film 202, n-type semiconductor layer 203, insulating layer 207, and heat dissipation substrate 211 in each light-emitting structure.

[0061] 6, the upper surface of the second VCSEL element 20b is flat. When the second optical member 30b is provided on the second VCSEL element 20b, the second optical member 30b may be supported by the flat upper surface of the semiconductor substrate 201. Alternatively, a spacer or a heat dissipation member may be provided between the second VCSEL element 20b and the second optical member 30b. Providing a spacer makes it easier to align the focal point of the second lens portion 32b with the second light-emitting point.

[0062] Note that the first VCSEL element 20a shown in FIG. 5A and the second VCSEL element 20b shown in FIG. 6 are examples. The components included in each VCSEL element 20 may be made of known materials. The shapes of some of the components included in each VCSEL element 20 may be modified. Each VCSEL element 20 may further include other components. For example, the VCSEL element disclosed in Japanese Patent Application Laid-Open No. 2020-123605 may be used as the second VCSEL element 20b. The entire disclosure of Japanese Patent Application Laid-Open No. 2020-123605 is incorporated herein by reference.

[0063] The third VCSEL element 20c that emits the third blue laser light has the same configuration as the second VCSEL element 20b, and can be made of the same semiconductor material as the second VCSEL element 20b.

[0064] In the first VCSEL element 20a, the interface between the p-type semiconductor layer 205 and the p-side reflective film 206 shown in FIG. 5A is the first emission surface from which the first laser light is emitted. In the first VCSEL element 20a, the p-side reflective film 206 is provided on the first emission surface, and the n-side reflective film 202 is provided on the opposite side of the first emission surface with respect to the active layer 204. The n-side reflective film 202 reflects the first laser light with a reflectivity of nearly 100%. The p-side reflective film 206 transmits the first laser light with a transmittance of several percent. The stop bands of the n-side reflective film 202 and the p-side reflective film 206 include the first oscillation wavelength.

[0065] In this specification, of the first VCSEL device 20a, the active layer 204 is also referred to as the "first layer," the p-side reflective film 206 is also referred to as the "first film," and the n-side reflective film 202 is also referred to as the "first reflective film."

[0066] In the second VCSEL element 20b, the interface between the n-side reflective film 202 and the n-type semiconductor layer 203 shown in FIG. 6 is defined as a second emission surface from which the second laser light is emitted. In the second VCSEL element 20b, the n-side reflective film 202 is provided on the second emission surface, and a p-side reflective film 206 is provided on the opposite side of the second emission surface relative to the active layer 204. The n-side reflective film 202 transmits the first laser light with a transmittance of 80% or more and transmits the second laser light with a transmittance of several percent. The p-side reflective film 206 reflects the second laser light with nearly 100% reflectance. The stop bands of the n-side reflective film 202 and the p-side reflective film 206 include the second lasing wavelength but not the first lasing wavelength. Because the band gap energy of the semiconductor material forming the second VCSEL element 20b is higher than the energy of the first laser light, the second VCSEL element 20b only absorbs a small amount of the first laser light. As a result, the second VCSEL element 20b can transmit the first laser light, which has a longer wavelength than the second laser light emitted by the second VCSEL element 20b.

[0067] The first laser light passes through a portion of the second VCSEL element 20b where the active layer 204, the p-type semiconductor layer 205, the p-side reflective film 206, the p-side electrode 208p, and the n-side electrode 208n are not provided. The first laser light does not pass through the second emission surface of the second VCSEL element 20b. That is, when viewed from above, the first laser light passes through a portion of the second emission surface where the intensity is 1 / e of the center intensity. 2 The region above (e is the base of the natural logarithm) does not have a portion that overlaps with the second exit surface of the second VCSEL element 20b and the second lens portion 32b.

[0068] In this specification, in the second VCSEL element 20b, the active layer 204 is also referred to as the "second layer," the n-side reflective film 202 is also referred to as the "second film," and the p-side reflective film 206 is also referred to as the "second reflective film."

[0069] In the third VCSEL element 20c, the interface between the n-side reflective film 202 and the n-type semiconductor layer 203 shown in FIG. 6 is defined as a third emission surface from which the third laser light is emitted. In the third VCSEL element 20c, the n-side reflective film 202 is provided on the third emission surface, and the p-side reflective film 206 is provided on the opposite side of the second emission surface with respect to the active layer 204. The n-side reflective film 202 transmits the first and second laser lights with a transmittance of 80% or more and transmits the third laser light with a transmittance of several percent. The p-side reflective film 206 reflects the third laser light with a reflectance of nearly 100%. The stop bands of the n-side reflective film 202 and the p-side reflective film 206 include the third oscillation wavelength but exclude the first and second oscillation wavelengths. Because the bandgap energy of the semiconductor material forming the third VCSEL element 20c is higher than the energies of the first and second laser lights, the third VCSEL element 20c absorbs the first and second laser lights to a lesser extent. As a result, the third VCSEL element 20c can transmit the first and second laser lights, which have longer wavelengths than the third laser light emitted by the third VCSEL element 20c.

[0070] The first laser light and the second laser light each pass through a portion of the third VCSEL element 20c where the active layer 204, the p-type semiconductor layer 205, the p-side reflective film 206, the p-side electrode 208p, and the n-side electrode 208n are not provided. The first laser light and the second laser light do not pass through the third emission surface of the third VCSEL element 20c. That is, when viewed from above, the first laser light and the second laser light each pass through a portion where the intensity is 1 / e of the center intensity. 2 The region above (e is the base of the natural logarithm) does not have a portion that overlaps with the third exit surface of the third VCSEL element 20c and the third lens portion 32c.

[0071] In this specification, in the third VCSEL device 20c, the active layer 204 is also referred to as the "third layer," the n-side reflective film 202 is also referred to as the "third film," and the p-side reflective film 206 is also referred to as the "third reflective film."

[0072] As described above, the second VCSEL element 20b and the third VCSEL element 20c can transmit laser light with a longer wavelength than the laser light emitted by each element. Therefore, the first to third VCSEL elements 20 are arranged so that the oscillation wavelengths become shorter with increasing distance from the top surface 10s. The second VCSEL element 20b and the third VCSEL element 20c may be reversed in position if the following requirement is met: the second VCSEL element 20b is made of a semiconductor material, such as GaN, that has low absorption of the third laser light, and the stop band of the n-side reflective film 202 included in the second VCSEL element 20b does not include the third oscillation wavelength.

[0073] Furthermore, two or more of the three VCSEL elements may emit laser light of the same oscillation wavelength. In this case, the n-side reflective film and p-side reflective film included in one of the two or more VCSEL elements are arranged so as not to overlap with the emission region from which the laser light of another VCSEL element located further below is emitted. This is to prevent the laser light emitted from the other VCSEL element from being reflected by the n-side reflective film and p-side reflective film.

[0074] Next, an example of the wiring configuration of the first VCSEL element 20a will be described with reference to FIG. 7. FIG. 7 is a top view schematically illustrating an example of the wiring configuration of the first VCSEL element 20a. The first VCSEL element 20a shown in FIG. 7 has 16 electrode pairs 208 arranged in 4 rows and 4 columns on the same side as the first emission surface that emits the first laser light. Each electrode pair 208 includes a p-side electrode 208p and an n-side electrode 208n. The 16 electrode pairs 208 correspond to the 16 first light-emitting points. The first VCSEL element 20a has, on the same side as the first emission surface, four p-side wirings 24p that extend along the X direction and are aligned along the Y direction, and four n-side wirings 24n that extend along the Y direction and are aligned along the X direction, on the same side as the first emission surface. Each p-side wiring 24p corresponds to one of the four electrode pairs 208 aligned along the X direction and is electrically connected to the p-side electrode 208p included in each of the four electrode pairs 208. Each n-side wiring 24n corresponds to four electrode pairs 208 aligned along the Y direction, and is electrically connected to an n-side electrode 208n included in each of the four electrode pairs 208. When viewed from above, the p-side wiring 24p and the n-side wiring 24n are insulated from each other at the intersections thereof by, for example, providing an insulating layer therebetween.

[0075] 6, the electrode pair 208, the p-side wiring 24p, and the n-side wiring 24n are provided on the opposite side to the first emission surface, which is the interface between the n-side reflective film 202 and the n-type semiconductor layer 203 shown in FIG.

[0076] By applying a forward voltage to the four p-side wirings 24p and the four n-side wirings 24n, the first laser light can be emitted simultaneously from the 16 first light-emitting points. Alternatively, the first laser light can be emitted individually from the 16 first light-emitting points. By applying a forward voltage to a certain p-side wiring 24p and a certain n-side wiring 24n, the first laser light can be emitted from the first light-emitting point corresponding to the electrode pair 208 electrically connected to these wirings.

[0077] In this specification, the electrode pair of the first VCSEL element 20a is also referred to as the "first electrode pair," the p-side wiring and the n-side wiring are also referred to as the "first p-side wiring" and the "first n-side wiring," respectively, and the p-side electrode and the n-side electrode are also referred to as the "first p-side electrode" and the "first n-side electrode," respectively.

[0078] The second VCSEL element 20b has the configuration shown in FIG. 6 and includes 16 electrode pairs arranged in 4 rows and 4 columns on the side opposite the second emission surface that emits the second laser light. Each electrode pair includes a p-side electrode 208p and an n-side electrode 208n. The 16 electrode pairs correspond to the 16 second light-emitting points. The second VCSEL element 20b also includes, on the side opposite the second emission surface, four p-side wirings extending along the X direction and aligned along the Y direction, and four n-side wirings extending along the Y direction and aligned along the X direction. These p-side wirings and n-side wirings may be provided on the upper surface of the heat dissipation substrate 211 as, for example, the metal film 210 shown in FIG. 6. The p-side wirings and n-side wirings are electrically connected to the p-side electrode 208p and the n-side electrode 208n, respectively, via the bonding layer 209 shown in FIG. 6. The electrical connections between the four p-side wirings and four n-side wirings and the 16 electrode pairs in the second VCSEL element 20b are as described with reference to Fig. 7. The p-side wirings and n-side wirings in the second VCSEL element 20b are provided in locations that do not interfere with the passage of the first laser light. In the second VCSEL element 20b, like the first VCSEL element 20a, the second laser light can be emitted simultaneously or individually from the 16 second light-emitting points.

[0079] If the second VCSEL element 20b has the same configuration as the first VCSEL element 20a shown in Fig. 5A, the electrode pair 208, p-side wiring 24p, and n-side wiring 24n are provided on the same side as the second emission surface, which is the interface between the p-type semiconductor layer 205 and the p-side reflective film 206 shown in Fig. 5A.

[0080] In this specification, the electrode pair of the second VCSEL element 20b is also referred to as the "second electrode pair," the p-side wiring and the n-side wiring are also referred to as the "second p-side wiring" and the "second n-side wiring," respectively, and the p-side electrode and the n-side electrode are also referred to as the "second p-side electrode" and the "second n-side electrode," respectively.

[0081] Similar to the second VCSEL element 20b, the third VCSEL element 20c has 16 electrode pairs arranged in 4 rows and 4 columns on the side opposite the third emission surface from which the third laser light is emitted. Each electrode pair includes a p-side electrode 208p and an n-side electrode 208n. The 16 electrode pairs correspond to the 16 third light-emitting points. The third VCSEL element 20c also has four p-side wirings extending along the X direction and aligned along the Y direction, and four n-side wirings extending along the Y direction and aligned along the X direction, on the side opposite the third emission surface. The p-side wirings and n-side wirings of the third VCSEL element 20c are located in locations that do not interfere with the passage of the first laser light and the second laser light. Similar to the first VCSEL element 20a, the third VCSEL element 20c can emit the third laser light simultaneously or individually from the 16 third light-emitting points.

[0082] If the third VCSEL element 20c has the same configuration as the first VCSEL element 20a shown in Fig. 5A, the electrode pair 208, the p-side wiring 24p, and the n-side wiring 24n are provided on the same side as the third emission surface, which is the interface between the p-type semiconductor layer 205 and the p-side reflective film 206 shown in Fig. 5A.

[0083] In this specification, the electrode pair of the third VCSEL element 20c is also referred to as the "third electrode pair," the p-side wiring and the n-side wiring are also referred to as the "third p-side wiring" and the "third n-side wiring," respectively, and the p-side electrode and the n-side electrode are also referred to as the "third p-side electrode" and the "third n-side electrode," respectively.

[0084] In the light source device 100 according to this embodiment, the rectangular region on the top surface of the cover 70 shown in FIG. 1 from which the first to third laser beams are emitted is divided into a plurality of sub-regions along the X and Y directions, and each sub-region can emit laser beams of various colors obtained from one or more of RGB at any intensity.

[0085] The number of p-side wirings and n-side wirings included in each VCSEL element 20 is not limited to four, but may be one or more. The number of p-side wirings and n-side wirings is determined by the number and arrangement of electrode pairs.

[0086] Next, a method of supplying power to each VCSEL element 20 will be described. The p-side wiring 24p and n-side wiring 24n included in the first VCSEL element 20a are electrically connected to a positive electrode and a negative electrode, respectively, provided on the upper surface 10s of the support substrate 10 via a first FPC 50a shown in Fig. 2. The first FPC 50a shown in Fig. 2 is electrically connected to the upper surface of the first VCSEL element 20a. When the electrode pair 208, the p-side wiring 24p, and the n-side wiring 24n are provided on the side opposite the first emission surface, the first FPC 50a is electrically connected to the lower surface of the first VCSEL element 20a.

[0087] In the example shown in FIG. 7 , some (e.g., the upper half) of the four p-side wirings 24p extending in the ±X directions are electrically connected to the same number of positive electrodes provided on the upper surface 10s via the first FPC 50a located on the −X side. The remaining (e.g., the lower half) of the four p-side wirings 24p extending in the ±X directions are electrically connected to the same number of positive electrodes provided on the upper surface 10s via the first FPC 50a located on the +X direction. Similarly, some (e.g., the left half) of the four n-side wirings 24n extending in the ±Y directions are electrically connected to the same number of negative electrodes provided on the upper surface 10s via the first FPC 50a located on the −Y side. The remaining (e.g., the right half) of the four n-side wirings 24n extending in the ±Y directions are electrically connected to the same number of negative electrodes provided on the upper surface 10s via the first FPC 50a located on the +Y direction.

[0088] The p-side wiring 24p can be electrically connected to a positive electrode provided on the top surface 10s via a first FPC 50a located on only one of the ±X-direction sides, for example. Similarly, the n-side wiring 24n can be electrically connected to a negative electrode provided on the top surface 10s via a first FPC 50a located on only one of the ±Y-direction sides, for example.

[0089] Although the first FPC 50a may be provided on only one of the ±X direction sides and only one of the ±Y direction sides, providing the first FPC 50a on both the ±X direction side and the ±Y direction side positions the center of gravity of the light source device 100 near the center in a top view. As a result, the light source device 100 can be stably placed on another device.

[0090] Similarly, the p-side wiring and n-side wiring included in the second VCSEL element 20b are electrically connected to the positive electrode and negative electrode provided on the upper surface 10s of the support substrate 10 via the second FPC 50b shown in Fig. 2. The second FPC 50b shown in Fig. 2 is electrically connected to the lower surface of the second VCSEL element 20b. When the electrode pair 208, the p-side wiring 24p, and the n-side wiring 24n are provided on the same side as the second emission surface, the second FPC 50b is electrically connected to the upper surface of the second VCSEL element 20b.

[0091] Similarly, the p-side wiring and n-side wiring included in the third VCSEL element 20c are electrically connected to the positive electrode and negative electrode, respectively, provided on the upper surface 10s of the support substrate 10 via the third FPC 50c shown in Fig. 2. The third FPC 50c shown in Fig. 2 is electrically connected to the lower surface of the third VCSEL element 20c. When the electrode pair 208, the p-side wiring 24p, and the n-side wiring 24n are provided on the same side as the third emission surface, the third FPC 50c is electrically connected to the upper surface of the third VCSEL element 20c.

[0092] Each FPC 50 can easily electrically connect the corresponding VCSEL element 20 to the electrodes provided on the upper surface 10s of the support substrate 10. For example, the first FPC 50a located on the ±X direction side (±Y direction side) can electrically connect multiple p-side wirings (n-side wirings) included in the first VCSEL element 20a to multiple positive electrodes (negative electrodes) provided on the upper surface 10s of the support substrate 10 all at once.

[0093] As described above, in the light source device 100 according to this embodiment, the three VCSEL elements 20 are electrically connected to electrodes provided on the upper surface 10s of the support substrate 10 via three FPCs 50. The electrodes are electrically connected to an external power supply device, making it possible to supply power to the three VCSEL elements 20.

[0094] Next, the material, shape, and dimensions of each component included in the light source device 100 will be described.

[0095] [Support substrate 10] The support substrate 10 may have a rectangular, circular, or elliptical flat plate shape. The support substrate 10 has an upper surface 10s and internal wiring. The support substrate 10 also has external electrodes on the surface opposite the upper surface 10s that are electrically connected to an external power supply device. Portions of the support substrate 10 other than the internal wiring and external electrodes may be formed, for example, from ceramics containing at least one selected from the group consisting of AlN, SiC, SiN, and alumina, or from metals or alloys thereof containing at least one selected from the group consisting of Ag, Cu, W, Au, Ni, Pt, and Pd. When formed from ceramic, low-temperature co-fired ceramic (LTCC) may be used. The dimensions of the support substrate 10 in the X and Y directions may be, for example, 2 mm to 100 mm, and the dimension in the Z direction may be, for example, 0.3 mm to 3.0 mm.

[0096] [3 VCSEL elements 20] As described above, the semiconductor material forming the three VCSEL elements 20 is the same. The dimensions of each VCSEL element 20 in the X and Y directions may be, for example, 0.2 mm to 30 mm, and the dimension in the Z direction may be, for example, 0.05 mm to 1 mm.

[0097] The upper surface 10s of the support substrate 10 and the first VCSEL element 20a can be joined using, for example, a solderable, sinterable, or brazable joining material. In soldering, components are joined by increasing the temperature of the solder to melt it and then decreasing the temperature to solidify it. In sintering, components are joined by heating a metal paste containing metal particles or a metal powder at a temperature lower than the melting point of the metal and baking it to solidify it. The solderable joining material can be, for example, at least one alloy selected from the group consisting of AuSn, SnCu, SnAg, and SnAgCu. The sinterable joining material can be, for example, a metal paste containing at least one type of particle selected from the group consisting of Ag particles, Cu particles, and Au particles. The brazable joining material can be, for example, at least one brazing material selected from the group consisting of gold brazing material, tin brazing material, and silver brazing material. Alternatively, anisotropic conductive film (ACF) or the like can be used.

[0098] [30 optical components] The three optical members 30 may be formed from at least one material selected from the group consisting of glass, quartz, synthetic quartz, sapphire, transparent ceramic, and plastic. The lens portion may be, for example, circular or elliptical in top view. The three optical members 30 may also be Fresnel lenses or diffractive optical elements. The dimensions of each optical member 30 in the X and Y directions are, for example, 0.2 mm to 30 mm, and the maximum dimension in the Z direction is, for example, 0.5 mm to 10 mm.

[0099] [First spacer 40a and second spacer 40b] The first spacer 40a and the second spacer 40b may be made of, for example, at least one selected from the group consisting of glass, plastic, sapphire, and perforated ceramic. The first spacer 40a and the second spacer 40b made of these materials can efficiently transfer heat generated by the second VCSEL element 20b and the third VCSEL element 20c to the support substrate 10. The dimension of each spacer 40a, 40b in the Z direction may be, for example, not less than 0.1 mm and not more than 2.0 mm.

[0100] [3 FPC50] Each FPC 50 is formed by bonding a plastic film to multiple thin wirings such as copper foil. Each FPC 50 is flexible and lightweight. Each FPC 50 may be rectangular or trapezoidal in top view. In the case of a trapezoidal shape, the relatively short upper side of each FPC 50 is electrically connected to the corresponding VCSEL element 20, and the relatively long lower side is electrically connected to an electrode provided on the upper surface 10s of the support substrate 10. This arrangement allows the pitch of the electrodes provided on the upper surface 10s of the support substrate 10 to be wider than the pitch of the light-emitting points of each VCSEL element 20, making it easy to provide the electrodes. Each FPC 50 can be connected to each VCSEL element 20 and the support substrate 10 by a known method using a conductive material.

[0101] [Side wall 60] The sidewall 60 may be rectangular, circular, or elliptical in top view, for example. The shape of the sidewall 60 may be designed according to the shape of the support substrate 10. The sidewall 60 may be formed from at least one selected from the group consisting of resin, Si, ceramic, glass, metal, and SPC (Steel Plate Colour) material, for example. When the support substrate 10 and the sidewall 60 are integrally molded, the sidewall 60 is formed from the same material as the support substrate 10. The dimensions of the sidewall 60 in the X and Y directions are, for example, equal to the dimensions of the support substrate 10 in the X and Y directions, respectively. The dimension of the sidewall 60 in the Z direction may be, for example, 0.5 mm or more and 50 mm or less.

[0102] The support substrate 10 and the sidewall 60 can be bonded together using, for example, the same method and material as used to bond the upper surface 10s of the support substrate 10 to the first VCSEL element 20a, as described above.

[0103] [Cover 70] The cover 70 may be rectangular, circular, or elliptical in top view, for example. The shape of the cover 70 may be designed according to the shape of the side wall 60. The cover 70 may be formed, for example, from the same light-transmitting material as the three optical members 30. The entire cover 70 may be light-transmitting. Alternatively, the portions of the cover 70 through which the first to third laser beams pass may be light-transmitting, and the remaining portions may not be light-transmitting. The light transmittance of the light-transmitting portions of the cover 70 for the first to third laser beams may be, for example, 60% or more, preferably 70% or more, and more preferably 80% or more. The dimensions of the cover 70 in the X and Y directions are, for example, equal to the dimensions of the side wall 60 in the X and Y directions, respectively. The dimension of the cover 70 in the Z direction may be, for example, 0.3 mm or more and 2.0 mm or less. The sidewall 60 and the cover 70 may be bonded together using the same method and material as used to bond the upper surface 10s of the support substrate 10 to the first VCSEL element 20a. An anti-reflection film may be provided on the light-incident side or the light-emitting side, or both, of the light-transmitting portion of the cover 70.

[0104] (Variation) Next, a modified example of the light source device 100 according to the present embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is an exploded perspective view schematically illustrating the configuration of a light source device 110 according to a modified example of the present embodiment. The light source device 110 shown in FIG. 8 differs from the light source device 100 shown in FIG. 1B in that the light source device 110 does not include the first FPC 50a, the second FPC 50b, and the third FPC 50c located on the ±Y direction sides. Since the first FPC 50a, the second FPC 50b, and the third FPC 50c are not located on the ±Y direction sides, the dimensions of the support substrate 10, the side wall 60, and the cover 70 in the Y direction may be reduced accordingly. A cross-sectional view of the light source device 110 parallel to the XZ plane is as shown in FIG. 2.

[0105] Fig. 9 is a top view schematically illustrating an example of the wiring configuration of the first VCSEL element 20a in this modification. The four p-side wirings 24p shown in Fig. 9 are similar to the four p-side wirings 24p shown in Fig. 7, but the four n-side wirings 24n shown in Fig. 9 differ from the four n-side wirings 24n shown in Fig. 7 in that they extend along the X direction and are aligned along the Y direction. Each n-side wiring 24n shown in Fig. 9 corresponds to four electrode pairs 208 aligned along the X direction, and is electrically connected to an n-side electrode 208n included in each of the four electrode pairs 208.

[0106] By applying a forward voltage to the four p-side wirings 24p and the four n-side wirings 24n, it is possible to simultaneously emit first laser light from 16 first light-emitting points. Alternatively, by applying a forward voltage to the m-th p-side wiring and n-side wiring from the +Y direction side (m is an integer from 1 to 4), it is possible to simultaneously emit first laser light from four first light-emitting points located between these wirings in a top view. The wiring for the second VCSEL element 20b and the third VCSEL element 20c is similar to the wiring for the first VCSEL element 20a.

[0107] In the light source device 110 according to this modification, the rectangular region on the top surface of the cover 70 shown in FIG. 1 from which the first to third laser beams are emitted is divided into a plurality of sub-regions along the X direction, and laser beams of various colors obtained from one or more of RGB can be emitted at any intensity from each sub-region extending along the X direction.

[0108] Next, another modification of the light source device according to this embodiment will be described. The light source device according to this modification emits infrared laser light in addition to RGB laser light. In addition to the components of the light source device 100 according to this embodiment, the light source device according to this modification further includes a fourth VCSEL element and a fourth optical member supported by the fourth VCSEL element. The first VCSEL element has a plurality of fourth light-emitting points arranged two-dimensionally, and each fourth light-emitting point emits fourth infrared laser light in the +Z direction. The fourth VCSEL element oscillates at a fourth oscillation wavelength. The fourth VCSEL element is supported directly or indirectly by the upper surface 10s of the support substrate 10, and three VCSEL elements 20 and three optical members 30 are arranged above the fourth VCSEL element and the fourth optical member. Each VCSEL element 20 can transmit fourth laser light having a longer wavelength than the laser light it emits.

[0109] The fourth VCSEL element has a configuration similar to that of the first VCSEL element 20a. Similar to the three optical members 30, the fourth optical member includes a plurality of fourth lens portions and a fourth flat plate portion supporting them. The fourth VCSEL element includes a plurality of fourth light-emitting points located on the optical axes of the plurality of fourth lens portions. Each fourth light-emitting point substantially coincides with the focal point of the corresponding fourth lens portion. The optical axis of the fourth laser light emitted from each fourth light-emitting point in the +Z direction substantially coincides with the optical axis of the corresponding fourth lens portion.

[0110] In the example shown in FIG. 3B, the fourth lens portion is located to the left of the first lens portion 32a, below and to the left of the second lens portion 32b, and below the third lens portion 32c in a top view. The fourth lens portion is located away from any of the first to third lens portions 32a to 32c. In other words, the fourth lens portion does not overlap any of the first to third lens portions 32a to 32c in a top view. The optical axis of the fourth laser light does not overlap any of the optical axis 20LA1 of the first laser light, the optical axis 20LA2 of the second laser light, and the optical axis 20LA3 of the third laser light. The optical axis of the fourth laser light does not pass through the first lens portion 32a, the second lens portion 32b, and the third lens portion 32c.

[0111] A light source device according to another modification of this embodiment further includes a third spacer that maintains the distance between the fourth VCSEL element and the first VCSEL element 20a. The first VCSEL element 20a is spaced apart from the fourth VCSEL element in the optical axis direction of the fourth laser light by the third spacer. The second VCSEL element 20b and the third VCSEL element 20c are also spaced apart from the fourth VCSEL element in the optical axis direction of the fourth laser light. The third spacer prevents the fourth optical member from contacting the first VCSEL element 20a.

[0112] A light source device according to another modification of this embodiment further includes a fourth FPC for feeding power to the fourth VCSEL element. The method of feeding power to the fourth VCSEL element is the same as the method of feeding power to the first VCSEL element 20a.

[0113] A light source device that emits infrared laser light in addition to RGB laser light can be used for infrared communication and visible light communication, for example.

[0114] Next, another modification of the light source device according to this embodiment will be described. This light source device according to this modification includes first to third photodiodes, each detecting a portion of the first to third laser beams, within a space defined by the support substrate 10, the sidewall 60, and the cover 70. The first photodiode is provided in a region of the first VCSEL element 20a that does not overlap with the first to third lens portions 32a to 32c in a top view. The second photodiode is provided in a region of the second VCSEL element 20b that does not overlap with the first to third lens portions 32a to 32c in a top view. The third photodiode is provided in a region of the third VCSEL element 20c that does not overlap with the first to third lens portions 32a to 32c in a top view.

[0115] The first optical member 30a has a structure in a region of its lower surface where the first laser light is incident, where it reflects a portion of the first laser light toward the first photodiode and transmits the remaining portion in the +Z direction. The second optical member 30b has a structure in a region of its lower surface where the second laser light is incident, where it reflects a portion of the second laser light toward the second photodiode and transmits the remaining portion in the +Z direction. The third optical member 30c has a structure in a region of its lower surface where the third laser light is incident, where it reflects a portion of the third laser light toward the third photodiode and transmits the remaining portion in the +Z direction. The intensity of the laser light detected by each photodiode may be, for example, 5% or less of the intensity of the laser light emitted from each light-emitting point.

[0116] The first photodiode detects the portion of the first laser light and generates a first photocurrent corresponding to the detected intensity. The first photocurrent can be extracted to the outside via the first FPC 50a. The second photodiode detects the portion of the second laser light and generates a second photocurrent corresponding to the detected intensity. The second photocurrent can be extracted to the outside via the second FPC 50b. The third photodiode detects the portion of the third laser light and generates a third photocurrent corresponding to the detected intensity. The third photocurrent can be extracted to the outside via the third FPC 50c.

[0117] By monitoring the values ​​of the first to third photocurrents extracted to the outside, the intensities of the first to third lasers can be determined.

[0118] Next, an example will be described in which laser beams emitted from a plurality of light source devices are combined to obtain mixed light. The first light source device includes a fourth VCSEL element 20a that emits a fourth infrared laser beam and a first VCSEL element 20a that is positioned above and spaced apart from the fourth light source device and emits a first red laser beam. The second light source device includes a second VCSEL element 20b that emits a second green laser beam and a third VCSEL element 20c that is positioned above and spaced apart from the second green laser beam. A mixed light of the first to fourth laser beams can be obtained by combining the fourth infrared laser beam and the first red laser beam emitted from the first light source device with the second green laser beam and the third blue laser beam emitted from the second light source device using a known method, such as by using a prism.

[0119] The first light source device and the second light source device can simplify the internal components compared to a single light source device that includes first to fourth VCSEL elements and that emits the first to fourth laser beams.

[0120] In the above example, the laser light emitted from the first light source device has red and infrared wavelengths, and the laser light emitted from the second light source device has green and blue wavelengths, but the wavelength combinations are not limited to this example. [Industrial Applicability]

[0121] The light source device of the present disclosure can be used in, for example, a head-mounted display, a projector, a display, and a lighting fixture. [Explanation of symbols]

[0122] 10 Support substrate 10s top 20L1 First laser beam 20L2 Second laser beam 20L3 Third laser beam 20LA1 Optical axis of first laser beam 20LA2 Optical axis of second laser beam 20LA3 Optical axis of the third laser beam 20 Three VCSEL elements 20a First VCSEL element 20b Second VCSEL element 20c Third VCSEL element 22a First light-emitting point 22b Second light-emitting point 22c Third luminous point 24n n-side wiring 24p p side wiring 30 Three optical components 30a First optical member 30b Second optical member 30c Third optical member 32a First lens section 32b Second lens section 32c Third lens section 34a 1st flat plate part 34b 2nd flat plate part 34c 3rd flat plate part 40a First spacer 40b Second spacer 50 3 FPCs 50a 1st FPC 50b 2nd FPC 50c 3rd FPC 60 side wall 70 Cover 100 Light source device 110 Light source device 201 Semiconductor substrate 202 n-side reflective film 203 n-type semiconductor layer 204 Active layer 205 p-type semiconductor layer 206 p side reflective film 207 Insulating layer 208 electrode pairs 208n n side electrode 208p p side electrode 209 Bonding layer 210 Metal Film 211 Heat dissipation board

Claims

1. a support substrate having an upper surface; a single first light-emitting element supported on the upper surface and having a plurality of first light-emitting points that emit first light in a predetermined direction intersecting the upper surface; a single second light-emitting element that is spaced apart from the first light-emitting element in the optical axis direction of the first light, transmits the first light, and has a plurality of second light-emitting points that emit second light in the predetermined direction; Equipped with A light source device in which the optical axis of the first light and the optical axis of the second light do not overlap.

2. a single third light-emitting element provided at a distance from the first light-emitting element and the second light-emitting element in the optical axis direction of the first light and the optical axis direction of the second light, the third light-emitting element having a plurality of third light-emitting points that transmit the first light and the second light and emit third light in the predetermined direction; The light source device according to claim 1 , wherein the optical axis of the third light does not overlap with the optical axis of the first light and the optical axis of the second light.

3. a support substrate having an upper surface; a first light-emitting element supported on the upper surface, the first light-emitting element having a plurality of first light-emitting points that emit first light in a predetermined direction intersecting the upper surface; a second light-emitting element that is provided apart from the first light-emitting element in the optical axis direction of the first light, transmits the first light, and has a plurality of second light-emitting points that emit second light in the predetermined direction; a third light-emitting element that is provided apart from the first light-emitting element and the second light-emitting element in the optical axis direction of the first light and the optical axis direction of the second light, transmits the first light and the second light, and has a plurality of third light-emitting points that emit third light in the predetermined direction; Equipped with the optical axis of the first light and the optical axis of the second light do not overlap, an optical axis of the third light does not overlap with an optical axis of the first light and an optical axis of the second light; the plurality of first light-emitting points are two-dimensionally arranged along a first direction and a second direction intersecting each other, or are one-dimensionally arranged along the first direction; the plurality of second light-emitting points are two-dimensionally arranged along the first direction and the second direction, or one-dimensionally arranged along the first direction; the plurality of third light-emitting points are two-dimensionally arranged along the first direction and the second direction, or one-dimensionally arranged along the first direction; the first light-emitting element has a plurality of first electrode pairs, each including a first p-side electrode and a first n-side electrode, on the same side as a surface that emits the first light, the plurality of first electrode pairs corresponding to the plurality of first light-emitting points, respectively; the second light-emitting element has a plurality of second electrode pairs, each including a second p-side electrode and a plurality of second n-side electrodes, on a side opposite to a surface that emits the second light, the plurality of second electrode pairs corresponding to the plurality of second light-emitting points, respectively; the third light-emitting element has a plurality of third electrode pairs, each including a third p-side electrode and a third n-side electrode, on the side opposite to the surface that emits the third light, and the plurality of third electrode pairs correspond to the plurality of third light-emitting points, respectively.

4. Equipped with a flexible printed circuit board, an electrode electrically connected to an external power supply device is provided on the upper surface; The light source device according to claim 3 , wherein the first to third light emitting elements are electrically connected to the electrodes via the flexible printed circuit board.

5. the first light-emitting element, the second light-emitting element, and the third light-emitting element are laser elements, the first light-emitting element oscillates at a first oscillation wavelength, the second light-emitting element oscillates at a second oscillation wavelength, the third light-emitting element oscillates at a third oscillation wavelength, the first oscillation wavelength is longer than the second oscillation wavelength; The light source device according to claim 2 , wherein the second oscillation wavelength is longer than the third oscillation wavelength.

6. the first oscillation wavelength is a red wavelength, the second oscillation wavelength is a green wavelength, The light source device according to claim 5 , wherein the third oscillation wavelength is a blue wavelength.

7. a first spacer that maintains a distance between the first light emitting element and the second light emitting element; a second spacer that maintains a distance between the second light emitting element and the third light emitting element; The light source device according to claim 2 , comprising:

8. a sidewall located around the top surface and surrounding the first light-emitting element, the second light-emitting element, and the third light-emitting element; The light source device according to claim 2 , further comprising: a cover bonded to an upper surface of the side wall, the cover transmitting the first light, the second light, and the third light.

9. 9. The light source device according to claim 2, wherein the first light-emitting element, the second light-emitting element, and the third light-emitting element are vertical-cavity surface-emitting laser elements.

10. the first light-emitting element is provided with a first layer and a first reflective film that reflects the first light on an opposite side of a surface from which the first light is emitted, with the first layer as a reference; the second light-emitting element is provided with a second layer and a second reflective film that transmits the first light and reflects the second light on an opposite side of the second layer from a surface that emits the second light, 10. The light source device of claim 9, wherein the third light-emitting element has a third layer and a third reflective film that transmits the first light and the second light and reflects the third light, on the opposite side of the surface that emits the third light relative to the third layer.

11. the first light-emitting element has a first film that transmits the first light provided on a surface that emits the first light, a second film that transmits the first light and the second light is provided on a surface of the second light-emitting element that emits the second light, 11. The light source device according to claim 9, wherein the third light-emitting element has a third film that transmits the first light, the second light, and the third light on a surface that emits the third light.

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