Photonic crystal surface-emitting element and light-emitting device

Abstract

Provided is a photonic crystal surface-emitting element that can increase freedom in the selection of an irradiation area.　A photonic crystal surface-emitting element according to the present technology comprises at least one element that includes a light emitting element part and an optical element part provided on the emission side of the light emitting element part, said light emitting element part including an active layer and a photonic layer that are layered on each other.

Description

Photonic crystal surface light emitting element and light emitting device

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a photonic crystal surface light-emitting element and a light-emitting device.

[0002] BACKGROUND ART Conventionally, photonic crystal surface light emitting devices such as photonic crystal surface emitting lasers (PCSELs) and photonic crystal light emitting diodes having a photonic crystal are known.

[0003] For example, Patent Document 1 discloses a photonic crystal surface emitting laser in which a mesa portion is provided on the surface of a light emitting element portion including an active layer and a photonic crystal layer.

[0004] For example, Patent Document 2 discloses a photonic crystal surface-emitting laser having a plurality of light-emitting regions each capable of emitting two laser beams in directions symmetrical with respect to the normal to the emission surface, with the emission angles being different from each other, and in which the plurality of light-emitting regions are selectively driven in a time series.

[0005] JP 2022-18026 A JP 2018-155628 A

[0006] However, for example, the photonic crystal surface emitting lasers described in Patent Documents 1 and 2 have room for improvement in terms of increasing the degree of freedom in selecting the irradiation area or improving the beam quality of the emitted light pattern.

[0007] Therefore, a main object of the present technology is to provide a photonic crystal surface light emitting device that can increase the degree of freedom in selecting an irradiation area or improve the beam quality of an emitted light pattern.

[0008] The present technology provides a photonic crystal surface light-emitting device including at least one element including: a light-emitting device section including an active layer and a photonic crystal layer stacked on each other; and an optical element section provided on the output side of the light-emitting device section. The optical element section may control the chief ray direction of the emitted light. The optical element section may tilt the chief ray direction with respect to the stacking direction of the active layer and the photonic crystal layer. The optical element section may control the chief ray direction so that an output light pattern, which is a pattern of the output light, is asymmetric with respect to a point of the output light pattern corresponding to the center of the photonic crystal in the photonic crystal layer. The optical element section may be a prism. The output surface of the optical element section may be tilted with respect to the stacking direction of the active layer and the photonic crystal layer. The optical element section may be a metaoptic. The device may include a plurality of the elements arranged along a plane perpendicular to the stacking direction of the active layer and the photonic crystal layer. The light emitting element units of the plurality of elements may emit light in the same light emission pattern, and at least one of the optical element units of the plurality of elements may tilt the chief ray direction of light from the corresponding light emitting element unit with respect to the stacking direction. Each of the optical element units of the plurality of elements may control the chief ray direction of light from the corresponding light emitting element unit to be non-parallel to each other. The emission surfaces of the optical element units of at least two of the plurality of elements may be tilted with respect to the stacking direction, and the inclination directions of the emission surfaces of the optical element units of the at least two elements may be different. The emission light patterns of the plurality of elements may be arranged two-dimensionally to form an irradiation pattern. Each of the emission light patterns of the plurality of elements may be a pattern in which spot-like or dot-like light is arranged two-dimensionally. Adjacent light beams may partially overlap. The emission light patterns of the plurality of elements may be arranged one-dimensionally to form an irradiation pattern. Each of the emission light patterns of the plurality of elements may be a band-like pattern whose longitudinal direction is a direction perpendicular to the arrangement direction of the emission light patterns of the plurality of elements. The planar shape of the optical element unit may be polygonal. The optical element portion may have a circular or elliptical shape in plan view.The element may include a rim portion provided around the optical element portion. There may be a gap between the optical element portion and the rim portion. The light-emitting element portion may emit a plurality of light beams toward the optical element portion. The optical element portion may split the light from the light-emitting element portion into a plurality of light beams. The principal ray direction of at least one of the plurality of light beams may be inclined with respect to the stacking direction of the active layer and the photonic crystal layer. The plurality of light beams may be emitted radially from the optical element portion. The light-emitting element portion may emit the light in the stacking direction of the active layer and the photonic crystal layer. The light from the light-emitting element portion may include fundamental mode light and higher-order mode light surrounding the fundamental mode light, and the fundamental mode light may be split into a plurality of first split light beams by the optical element portion, and the higher-order mode light may be emitted from the optical element portion as second split light beams spatially separated from the plurality of first split light beams. The photonic crystal surface light-emitting element may be provided with a light-shielding portion that blocks the second split light beams. The light from the light-emitting element unit may include fundamental mode light and higher-order mode light surrounding the fundamental mode light, and the photonic crystal surface light-emitting element may be provided with a light-blocking unit that blocks the higher-order mode light. The optical element unit may include a metasurface. The metasurface may have a pillar group including a plurality of pillars arranged two-dimensionally on a reference plane. The far-field pattern of the light emitted from the optical element unit may be a multi-point dot pattern. The pillar group may include a first pillar and at least one second pillar whose center is located within a distance range from the center of the first pillar within five times the radius of the first pillar and whose diameter differs from that of the first pillar by 50 nm or more. The light-emitting element unit may be provided on one side of a substrate, and the optical element unit may be provided on the other side of the substrate. The pillar group may be part of the substrate. The pillar group may be a separate member from the substrate. The optical element unit may have an anti-reflection film disposed between the pillar group and the substrate. The anti-reflection film may have a thickness different between a portion where the pillars are arranged and a portion where the pillars are not arranged.The optical element unit may have an anti-reflection film covering at least a portion of the surface of the pillar group. The anti-reflection film may be provided along the surface of the pillar and the reference plane. The anti-reflection film may cover the tops of the pillars. The anti-reflection film may cover a portion of the reference plane where the pillars are not provided. The optical element unit may have a buried layer that embeds the pillar group. The optical element unit may have an anti-reflection layer disposed on the buried layer. The metasurface may be designed so that a phase difference of ½ of the emission wavelength occurs between a first region corresponding to an area of ​​40% or less including the center of the light-emitting region of the light-emitting element unit and a second region corresponding to an area of ​​40% or more of the light-emitting region on the outer periphery of the first region. The light-emitting element unit may emit light toward the optical element unit, and the metasurface may be designed to reduce unevenness in illuminance of the light. The light emitting element portion may emit light toward the optical element portion, and the metasurface may have a plurality of pillars each having an anisotropic shape in a plan view, the plurality of pillars being arranged so as to reduce unevenness in illuminance of the light. The present technology also provides a light emitting device comprising: a light emitting element portion including an active layer and a photonic crystal layer stacked on each other, an optical element portion provided on the emission side of the light emitting element portion, and a mounting substrate on which the photonic crystal surface light emitting element is mounted.

[0009] 6A is a cross-sectional view (part 1) of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6B is a cross-sectional view (part 2) of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6C is a plan view of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6D is a bottom view of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6E is a diagram showing an irradiation pattern of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6A is a diagram showing emission directions of first and second elements of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6B is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6F is a cross-sectional view (part 1) of a light-emitting device including a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6G is a cross-sectional view (part 2) of a light-emitting device including a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6H is a flowchart for describing an example of a method for manufacturing a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 6I is a cross-sectional view of each process of an example of a method for manufacturing a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 1 is a cross-sectional view of each step of an example of a manufacturing method of a photonic crystal surface light emitting device according to Example 1 of an embodiment of the present technology. FIG. 2 is a cross-sectional view of each step of an example of a manufacturing method of a photonic crystal surface light emitting device according to Example 1 of an embodiment of the present technology. FIG. 3 is a cross-sectional view of each step of an example of a manufacturing method of a photonic crystal surface light emitting device according to Example 1 of an embodiment of the present technology. FIG. 4 is a cross-sectional view of each step of an example of a manufacturing method of a photonic crystal surface light emitting device according to Example 1 of an embodiment of the present technology. FIG. 5 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 6 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology.22A is a plan view of a photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 22B is a view showing the emission directions of first and second elements of the photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 22B is a view showing the emission directions of third and fourth elements of the photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 22A is a view showing the emission directions of first and second elements of the photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 22B is a view showing the emission directions of third and fourth elements of the photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 22B is a view showing the emission directions of third and fourth elements of the photonic crystal surface light emitting device according to Example 2 of an embodiment of the present technology. FIG. 27A is a view showing the emission directions of first and second elements of the photonic crystal surface light emitting device according to Example 3 of an embodiment of the present technology. FIG. 27B is a view showing the emission directions of third and fourth elements of the photonic crystal surface light emitting device according to Example 3 of an embodiment of the present technology. FIG. 32A is a diagram showing emission directions of first and second elements of a photonic crystal surface light emitting device according to Example 4 of an embodiment of the present technology. FIG. 32B is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 4 of an embodiment of the present technology. FIG. 32B is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 4 of an embodiment of the present technology. FIG. 32C is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 32D is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 32E is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 32F is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 5 of an embodiment of the present technology. FIG. 32G is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light emitting device according to Example 6 of an embodiment of the present technology.FIG. 1 is a plan view of a photonic crystal surface light emitting device according to Example 6 of an embodiment of the present technology. FIG. 2 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device according to Example 7 of an embodiment of the present technology. FIG. 3 is a cross-sectional view (part 3) of a photonic crystal surface light emitting device according to Example 7 of an embodiment of the present technology. FIG. 4 is a cross-sectional view of a photonic crystal surface light emitting device according to Example 8 of an embodiment of the present technology. FIG. 5 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device according to Example 9 of an embodiment of the present technology. FIG. 6 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device according to Example 9 of an embodiment of the present technology. FIG. 7 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device according to Example 9 of an embodiment of the present technology. FIG. 8 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device according to Example 10 of an embodiment of the present technology. 57A is a plan view of a photonic crystal surface light emitting device according to Example 10 of an embodiment of the present technology. FIG. 57B is a cross-sectional view (part 1) of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57C is a cross-sectional view (part 2) of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57D is a cross-sectional view of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57E is a cross-sectional view of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57F is a cross-sectional view of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57G is a cross-sectional view of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology. FIG. 57H is a cross-sectional view of a photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology.59B is a diagram showing emission directions of third and fourth elements of the photonic crystal surface light emitting device according to Modification 2 of Example 1 of an embodiment of the present technology. FIG. 59C is a partial perspective view schematically showing a photonic crystal surface light emitting device according to Modification 2 of Example 1 of an embodiment of the present technology. FIG. 59D is a cross-sectional view of a photonic crystal surface light emitting device according to Modification 3 of Example 1 of an embodiment of the present technology. FIG. 59E is a diagram for explaining a method of determining prism parameters. FIG. 59F is a cross-sectional view of a photonic crystal surface light emitting device according to Example 12 of an embodiment of the present technology. FIG. 59G is a plan view of a metasurface of a photonic crystal surface light emitting device according to Example 12 of an embodiment of the present technology. FIG. 59H is a cross-sectional view showing an emission state of a photonic crystal surface light emitting device according to Example 12 of an embodiment of the present technology. FIG. 59H is a diagram showing an emission light pattern (far-field pattern) of a photonic crystal surface light emitting device according to Example 13 of an embodiment of the present technology. FIG. 59I is a cross-sectional view of a part of the metasurface of a photonic crystal surface light emitting device according to Example 14 of an embodiment of the present technology. FIG. 59I is a cross-sectional view of a part of the metasurface of a photonic crystal surface light emitting device according to Example 15 of an embodiment of the present technology. 10 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 16 of an embodiment of the present technology. FIG. 11 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 17 of an embodiment of the present technology. FIG. 12 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 18 of an embodiment of the present technology. FIG. 13 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 19 of an embodiment of the present technology. FIG. 14 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 20 of an embodiment of the present technology. FIG. 15 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 20.5 of an embodiment of the present technology. FIG. 16 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 22 of an embodiment of the present technology. FIG. 17 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 23 of an embodiment of the present technology. FIG. 18 is a partial cross-sectional view of a metasurface of a photonic crystal surface light-emitting device according to Example 24 of an embodiment of the present technology.85A is a schematic cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 25 of an embodiment of the present technology. FIG. 85B is a diagram showing an emission light pattern (far-field pattern) of a photonic crystal surface light-emitting device according to Example 30 of an embodiment of the present technology. FIG. 85B is a diagram showing an emission light pattern (far-field pattern) of a photonic crystal surface light-emitting device according to Example 30 of an embodiment of the present technology. FIG. 85B is a diagram for explaining a planar configuration of the metasurface of a photonic crystal surface light-emitting device according to Example 30 of an embodiment of the present technology. FIG. 88A is a schematic cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 32 of an embodiment of the present technology. 88B is a schematic cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 32 of an embodiment of the present technology. FIG. 88B is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 33 of an embodiment of the present technology. FIG. 88C is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 34 of an embodiment of the present technology. FIG. 88D is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 35 of an embodiment of the present technology. FIG. 88E is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 36 of an embodiment of the present technology. FIG. 88F is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 37 of an embodiment of the present technology. FIG. 88G is a cross-sectional view showing an emission state of a photonic crystal surface light-emitting device according to Example 38 of an embodiment of the present technology.Fig. 1 is a plan view of a metasurface of a photonic crystal surface light emitting device according to Example 32 of an embodiment of the present technology, and is a diagram showing the azimuth angle of a pillar. Fig. 2 is a diagram showing an example of application of a photonic crystal surface light emitting device according to Example 1 of an embodiment of the present technology to a distance measurement device. Fig. 3 is a block diagram showing an example of a schematic configuration of a vehicle control system. Fig. 4 is an explanatory diagram showing an example of an installation position of a distance measurement device.

[0010] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations will be denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below are representative embodiments of the present technology, and are not intended to narrow the scope of the present technology. Even when this specification describes that the photonic crystal surface light-emitting element and light-emitting device according to the present technology achieve multiple effects, it is sufficient that the photonic crystal surface light-emitting element and light-emitting device according to the present technology achieve at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved.

[0011] The description will be made in the following order: 0. Introduction 1. Photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology 2. Photonic crystal surface light-emitting device according to Example 2 of an embodiment of the present technology 3. Photonic crystal surface light-emitting device according to Example 3 of an embodiment of the present technology 4. Photonic crystal surface light-emitting device according to Example 4 of an embodiment of the present technology 5. Photonic crystal surface light-emitting device according to Example 5 of an embodiment of the present technology 6. Photonic crystal surface light-emitting device according to Example 6 of an embodiment of the present technology 7. Photonic crystal surface light-emitting device according to Example 7 of an embodiment of the present technology 8. Photonic crystal surface light-emitting device according to Example 8 of an embodiment of the present technology 9. Photonic crystal surface light-emitting device according to Example 9 of an embodiment of the present technology 10. Photonic crystal surface light-emitting device according to Example 10 of an embodiment of the present technology 11. Photonic crystal surface light-emitting device according to Example 11 of an embodiment of the present technology 12. Photonic crystal surface light-emitting device according to Example 12 of an embodiment of the present technology 13. Photonic crystal surface light-emitting device according to Example 13 of an embodiment of the present technology 14. Photonic crystal surface light emitting device according to Example 14 of an embodiment of the present technology 15. Photonic crystal surface light emitting device according to Example 15 of an embodiment of the present technology 16. Photonic crystal surface light emitting device according to Example 16 of an embodiment of the present technology 17. Photonic crystal surface light emitting device according to Example 17 of an embodiment of the present technology 18. Photonic crystal surface light emitting device according to Example 18 of an embodiment of the present technology 19. Photonic crystal surface light emitting device according to Example 19 of an embodiment of the present technology 20. Photonic crystal surface light emitting device according to Example 20 of an embodiment of the present technology 20.5. Photonic crystal surface light-emitting device according to Example 20.5 of an embodiment of the present technology 21. Photonic crystal surface light-emitting device according to Example 21 of an embodiment of the present technology 22. Photonic crystal surface light-emitting device according to Example 22 of an embodiment of the present technology 23. Photonic crystal surface light-emitting device according to Example 23 of an embodiment of the present technology 24. Photonic crystal surface light-emitting device according to Example 24 of an embodiment of the present technology 25. Photonic crystal surface light-emitting device according to Example 25 of an embodiment of the present technology 26. Photonic crystal surface light-emitting device according to Example 26 of an embodiment of the present technology 27. Photonic crystal surface light-emitting device according to Example 27 of an embodiment of the present technology 28. Photonic crystal surface light-emitting device according to Example 28 of an embodiment of the present technology 29. Photonic crystal surface light-emitting device according to Example 29 of an embodiment of the present technology 30. Photonic crystal surface light-emitting device according to Example 30 of an embodiment of the present technology 31. Photonic crystal surface light-emitting device according to Example 31 of an embodiment of the present technology 32. Photonic crystal surface light-emitting device according to Example 32 of an embodiment of the present technology 33. Photonic crystal surface light emitting device according to Example 33 of an embodiment of the present technology 34. Photonic crystal surface light emitting device according to Example 34 of an embodiment of the present technology 35. Modification of the present technology 36. Application example to electronic devices 37. Example of application of photonic crystal surface light emitting device to a distance measurement device 38. Example of installation of a distance measurement device on a moving object

[0012] <0. Introduction>

[0013] Photonic crystal surface-emitting lasers (PCSELs), which are representative of photonic crystal surface-emitting devices, are new semiconductor lasers that utilize the large-area resonance at singular points (M points) in the band structure of two-dimensional photonic crystals, and enable control of the beam emission direction and emission of various beam patterns by modulating the size and position of the lattice points. As shown in the following literature [1], [2], and [3], a PCSEL is unique in that it can emit various beam patterns, such as flash patterns and multi-dot patterns, from a single photonic crystal without using external optical elements.

[0014] [1] S. Noda, et al., IEEE J. Sel. Topics Quantum Electronics 23, 4900107 (2017). [2] R. Sakata, S. Noda, et al., Nature Communications 11, 3487 (2020). [3] R. Sakata, S. Noda, et al., Applied Physics Letters -Perspective- 122, 130503 (2023).

[0015] In a photonic crystal surface-emitting laser, a photonic crystal layer is placed near the active layer, and the evanescent component of the light wave confined in the active layer is subjected to the resonance and diffraction effects of the photonic crystal. The photonic crystal has, for example, a square lattice structure, and the lattice constant a is set taking into account the effective refractive index so that it matches the wavelength of the light generated in the active layer. Inside the photonic crystal, due to the existence of a periodic refractive index distribution, the light wave takes on a state represented by a Bloch wave.

[0016] However, with PCSELs, the beam is limited in its emission by the diffraction phenomenon in the photonic crystal, and as described in Patent Document 2 (JP 2018-155628), for example, there is a problem that the beam can only be emitted at the same angle relative to the normal direction. This is also confirmed by the example of Kyoto University's projection pattern in FIG. 1 of the above-mentioned document [3], "Emission of various beam patterns."

[0017] For this reason, conventional PCSELs can only generate point-symmetric beam patterns (emission light patterns), and cannot generate beam patterns (e.g., non-point-symmetric beam patterns) that irradiate only an arbitrary area (e.g., a desired area). In other words, conventional technologies have room for improvement in terms of increasing the degree of freedom in selecting the irradiation area.

[0018] Therefore, after extensive research, the inventors have succeeded in increasing the degree of freedom in selecting the irradiation area by providing an optical element section in the light-emitting element section, which is a new discovery made by the inventors.

[0019] The inventors then developed a photonic crystal surface light emitting device according to the present technology as a photonic crystal surface light emitting device that embodies this new finding. Furthermore, the inventors developed a light emitting device according to the present technology as a light emitting device in which the photonic crystal surface light emitting device according to the present technology is mounted on a mounting substrate.

[0020] Hereinafter, a photonic crystal surface light-emitting device according to an embodiment of the present technology will be described in detail using several examples. In the following, in cross-sectional views such as FIG. 1 , the upper side will be referred to as "up" and the lower side will be referred to as "down" as appropriate.

[0021] 1. Photonic crystal surface light emitting device according to example 1 of an embodiment of the present technology> Fig. 1 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 10 according to example 1 of an embodiment of the present technology. Fig. 2 is a cross-sectional view (part 2) of the photonic crystal surface light emitting device 10 according to example 1 of an embodiment of the present technology. Fig. 3 is a plan view of the photonic crystal surface light emitting device 10 according to example 1 of an embodiment of the present technology. Fig. 4 is a bottom view of the photonic crystal surface light emitting device 10 according to example 1 of an embodiment of the present technology. Fig. 1 is a cross-sectional view taken along line 1-1 in Fig. 3. Fig. 2 is a cross-sectional view taken along line 2-2 in Fig. 3.

[0022] <Configuration of Photonic Crystal Surface Light Emitting Element and Light Emitting Device> As shown in Figures 1 to 4 , a photonic crystal surface light emitting element 10 according to Example 1 of an embodiment of the present technology includes at least one element E (four in this case, e.g., first to fourth elements E1 to E4) including a light emitting element section LE including an active layer 104 and a photonic crystal layer 106 stacked on each other, and an optical element section 200 provided on the emission side of the light emitting element section LE. Hereinafter, the direction in which the active layer 104 and the photonic crystal layer 106 are stacked is also referred to as the "stacking direction." The stacking direction coincides with the normal direction N of the substrate 101. Hereinafter, the normal direction N of the substrate 101 is also referred to as the "substrate normal direction."

[0023] The first element E1 includes a first light-emitting element unit LE1 and a first optical element unit 200A. The second element E2 includes a second light-emitting element unit LE2 and a second optical element unit 200B. The third element E3 includes a third light-emitting element unit LE3 and a third optical element unit 200C. The fourth element E4 includes a fourth light-emitting element unit LE4 and a fourth optical element unit 200D.

[0024] An example of the photonic crystal surface light emitting element 10 is a photonic crystal-surface emitting laser (PCSEL). An example of the photonic crystal surface light emitting element 10 is a rear surface emitting photonic crystal surface emitting laser. An example of the oscillation wavelength λ of the photonic crystal surface light emitting element 10 is in the NIR (Near Infrared Ray) band, for example, 940 nm.

[0025] The photonic crystal surface light emitting device 10 includes, for example, a substrate 101. Light emitting element units LE of the first to fourth elements E1 to E4 (e.g., first to fourth light emitting element units LE1 to LE4) are provided on one surface (front surface) of the substrate 101, and optical element units 200 of the first to fourth elements E1 to E4 (e.g., first to fourth optical element units 200A to 200D) are provided on the other surface (rear surface) of the substrate 101. Each optical element unit 200 is, for example, a prism.

[0026] The first to fourth light-emitting element units LE1 to LE4 are two-dimensionally arranged (e.g., in a matrix) along one surface (one surface perpendicular to the stacking direction) of the substrate 101 (see FIG. 4). The first to fourth optical element units 200A to 200D are two-dimensionally arranged (e.g., in a matrix) on the other surface of the substrate 101 (see FIG. 3). In each element E, the substrate 101 is sandwiched between the light-emitting element unit LE and the optical element unit 200.

[0027] As an example, the photonic crystal surface light emitting element 10 further includes two dummy element elements DE arranged on one surface of the substrate 101 so as to sandwich a light emitting element element array in which four light emitting element elements LE are arranged two-dimensionally (for example, in a matrix arrangement), an anode electrode 111 arranged on each light emitting element element LE, and a cathode wiring 113 arranged on each dummy element element DE. The dummy element elements DE are also called "non-light emitting element portions."

[0028] In the light-emitting element section LE, as an example, the active layer 104 and the photonic crystal layer 106 are arranged close to each other in the stacking direction. The light-emitting section is configured to include the active layer 104 and the photonic crystal layer 106. Here, the active layer 104 is arranged on the substrate 101 side (upper side, for example, the n-side) of the photonic crystal layer 106, but the active layer 104 may also be arranged on the opposite side of the photonic crystal layer 106 from the substrate 101 side (lower side, for example, the p-side). Note that when the active layer 104 is arranged on the n-side of the photonic crystal layer 106, the electrical characteristics are improved compared to when it is arranged on the p-side.

[0029] The light-emitting element section LE has first and second cladding layers 103 and 107 that sandwich a light-emitting section including an active layer 104 and a photonic crystal layer 106. The first cladding layer 103 is disposed on the substrate 101 side (upper side) of the light-emitting section, and the second cladding layer 107 is disposed on the opposite side of the light-emitting section from the substrate 101 side (lower side).

[0030] In the light emitting element section LE, the active layer 104, the photonic crystal layer 106, and the first and second cladding layers 103 and 107 form a resonator.

[0031] The light-emitting element section LE further has a first contact layer 102 arranged on the substrate 101 side (upper side) of the resonator, a reflector 108 arranged on the opposite side (lower side) of the resonator from the substrate 101 side, and a second contact layer 109 arranged on the opposite side (lower side) of the reflector 108 from the resonator side.

[0032] That is, in the light emitting element section LE, a first contact layer 102, a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108 and a second contact layer 109 are arranged in this order on a substrate 101.

[0033] The light-emitting element section LE has a light-emitting mesa LM including at least a part (for example, the entirety) of the resonator. Here, the light-emitting mesa LM is provided to protrude from the first contact layer 102, and is configured to include a first cladding layer 103, an active layer 104, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109. Here, the light-emitting mesa LM is cylindrical, but it may also be in the shape of a truncated cone, an elliptical cylinder, an elliptical truncated cone, a polygonal pillar, a polygonal truncated pyramid, or the like.

[0034] The dummy element portion DE is configured in a similar manner to the light-emitting element portion LE and includes a dummy mesa DM. The dummy mesa DM is also called a "non-light-emitting mesa" or "pedestal portion." Here, the dummy mesa DM protrudes from the first contact layer 102 and includes a first cladding layer 103, an active layer 104, a base material 106BM of the photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109.

[0035] That is, the four light emitting element units LE and the two dummy element units DE share the first contact layer 102 .

[0036] The light emitting mesa LM and the dummy mesa DM are covered with an insulating film 110. For example, the insulating film 110 does not cover the center of the top (second contact layer 109) of the light emitting mesa LM, and an anode electrode 111 (p-side electrode) is provided on this center. For example, the insulating film 110 does not cover a portion of the first contact layer 102 between the light emitting element portion LE and the dummy element portion DE, and a cathode electrode 112 (n-side intermediate electrode) is provided on this portion. A cathode wiring 113 for cathode pull-up is provided along the dummy mesa DM covered with the insulating film 110. One end of the cathode wiring 113 contacts the cathode electrode 112, a middle portion is provided on the side surface of the dummy mesa DM via the insulating film 110, and the other end is provided on the top (second contact layer 109) of the dummy mesa DM via the insulating film 110.

[0037] That is, the photonic crystal surface light emitting element 10 has an intra-cavity structure in which the anode electrode 111, the cathode electrode 112, and the cathode wiring 113 are provided on the same side (bottom side) of the substrate 101. The photonic crystal surface light emitting element 10 has an electrode layout in which the anodes are independent and the cathodes are common to the multiple light emitting element components LE, and each light emitting element component LE can be driven independently.

[0038] As an example, the photonic crystal surface light emitting element 10 is flip-chip mounted (junction-down mounted) on the mounting substrate 15 (see FIGS. 7 and 8). That is, in the photonic crystal surface light emitting element 10, the light emitting element section LE is bonded to the mounting substrate 15 via bumps. In this manner, the photonic crystal surface light emitting element 10 is electrically and mechanically connected to the mounting substrate 15. The light emitting device 1 is configured to include the photonic crystal surface light emitting element 10 and the mounting substrate 15 on which the photonic crystal surface light emitting element 10 is mounted.

[0039] The mounting substrate 15 is, for example, a substrate (drive substrate) having a laser driver (laser drive circuit) or a wiring substrate electrically connected to the laser driver. Here, the mounting substrate 15 is a drive substrate. The laser driver of the mounting substrate 15 has, for example, an nMOS (n-type Metal-Oxide-Semiconductor Field-effect Transistor) as a switching element. In particular, by using an nMOS as the switching element, the switching element can be made smaller, leading to a smaller laser driver and improved design freedom. Note that the laser driver may have a pMOS (p-type Metal-Oxide-Semiconductor Field-effect Transistor) instead of an nMOS.

[0040] (Substrate) The substrate 101 is, for example, a semiconductor substrate containing impurities, a semi-insulating substrate (e.g., a semiconductor substrate containing no impurities), or the like. Here, the substrate 101 is made of GaAs. In order to reduce light absorption, the substrate 101 is preferably made of, for example, lightly doped GaAs (n-GaAs or p-GaAs), SI (Semi-Insulating)-GaAs, or the like. Furthermore, the substrate 101 is preferably transparent to the emission wavelength of the active layer 104.

[0041] (First Contact Layer) The first contact layer 102 is, for example, an Al layer of a first conductivity type (for example, n-type). ｘ０ Ga １－ｘ０ The first contact layer 102 is made of, for example, n-GaAs (0≦x0<1). The first contact layer 102 contains an n-type impurity such as silicon (Si). The first contact layer 102 not only makes an ohmic contact between the first cladding layer 103 and the cathode electrode 112, but also functions as a current diffusion layer that allows current to reach the center of the light emitting element portion LE.

[0042] (First Cladding Layer) The first cladding layer 103 is, for example, an Al layer of a first conductivity type (for example, n-type). ｘ１ Ga １－ｘ１ The first cladding layer 103 is made of As (0≦x1<1). The cladding layer is also called a “spacer layer.” The first cladding layer 103 contains an n-type impurity such as silicon (Si).

[0043] (Active Layer) The active layer 104 has, for example, a quantum well structure including a barrier layer and a well layer made of a GaAs-based compound semiconductor. ｘ２ Ga １－ｘ２ A well layer made of As (0<x2<1) and undoped In ｘ３ Ga １－ｘ３ The active layer 104 has a multiple quantum well structure (MQW structure) in which barrier layers made of As (0<x3<1) are alternately stacked. Instead of the multiple quantum well structure, the active layer 104 may have a single quantum well structure (QW structure), a quantum dot structure, a quantum wire structure, or the like. The emission wavelength of the active layer 104 is, for example, 935 nm. The active layer is also called an "emitting layer."

[0044] (Photonic Crystal Layer) The photonic crystal layer 106 provides a photonic crystal resonance and diffraction effect to the light emitted from the active layer 104 adjacent in the stacking direction.

[0045] The photonic crystal layer 106 includes, for example, a base portion 106b that is part of a plate-shaped base material 106BM (see FIG. 10 ), and a modified refractive index periodic structure 106a (photonic crystal) arranged on the base portion 106b. In the modified refractive index periodic structure 106a, modified refractive index areas are arranged periodically (e.g., in a two-dimensional lattice pattern) along the in-plane direction of the base portion 106b. The modified refractive index periodic structure 106a generates a periodic refractive index distribution in the photonic crystal layer 106. In the photonic crystal layer 106, the period (e.g., the spacing between lattice points, the lattice constant, the hole spacing) of the modified refractive index areas is, for example, the same as or close to the emission wavelength of the active layer 104. The material of the base material 106BM is, for example, Al. ｘ５ Ga １－ｘ５ The modified refractive index periodic structure 106 a is preferably, but not limited to, GaAs (0≦x5<1), for example, GaAs. The modified refractive index region is, for example, an air hole (air or vacuum). Here, the modified refractive index periodic structure 106 a is provided at a position corresponding to the center of the surface of the active layer 104, but may be provided at a position corresponding to the entire surface of the active layer 104.

[0046] Due to the presence of the periodic refractive index distribution described above, light of a specific wavelength (e.g., oscillation wavelength λ) forms a two-dimensional standing wave state in a specific direction within the photonic crystal plane within the photonic crystal layer 106. In the photonic crystal layer 106, diffraction occurs not only in directions parallel to the photonic crystal plane but also in directions perpendicular thereto, allowing a beam with a narrow exit angle to be emitted in a direction intersecting the in-plane direction (e.g., perpendicular to the plane), thereby providing a surface emission output.

[0047] The photonic crystal layer 106 can control the intensity and emission direction of the beam by adjusting the positions and areas of the holes (air holes) and the modulation amounts thereof.

[0048] (Second Cladding Layer) The second cladding layer 107 is, for example, an AlN layer of a second conductivity type (for example, p-type). ｘ６ Ga １－ｘ６The second cladding layer 107 is made of As (0≦x6<1). The cladding layer is also called a “spacer layer.” The second cladding layer 107 contains a p-type impurity such as carbon (C).

[0049] (Reflector) Reflector 108 is provided to reflect light emitted from the light emitting section including active layer 104 and photonic crystal layer 106 to the opposite side (lower side) from substrate 101 toward substrate 101 (upper side) and use it as emitted light (to improve light utilization efficiency). In this way, reflector 108 is provided to improve efficiency and is not essential.

[0050] The reflecting mirror 108 is, for example, a semiconductor multilayer reflecting mirror. A multilayer reflecting mirror is also called a distributed Bragg reflector. More specifically, the reflecting mirror 108 is, for example, a second conductivity type (for example, p-type) semiconductor multilayer reflecting mirror, and has a structure in which a plurality of types (for example, two types) of semiconductor layers having different refractive indices are alternately stacked with an optical thickness of ¼ wavelength of the emission wavelength. Each refractive index layer of the reflecting mirror 108 is made of an AlGaAs-based compound semiconductor of the second conductivity type (for example, p-type). Specifically, the reflecting mirror 108 has a low refractive index layer made of, for example, p-Al ｘ７ Ga １－ｘ７ As (0<x7<1), and the high refractive index layer is, for example, p-Al ｘ８ Ga １－Ｘ８ As (0≦x8<x7).

[0051] (Second Contact Layer) The second contact layer 109 is, for example, an Al layer of a second conductivity type (for example, p-type). ｘ９ Ga １－ｘ９ The second contact layer 109 is made of As (0≦x9<1), for example, p-GaAs. The second contact layer 109 contains a p-type impurity such as carbon (C). The second contact layer 109 is a layer for making ohmic contact between the reflecting mirror 108 and the anode electrode 111.

[0052] (Insulating Film) The insulating film 110 is made of, for example, SiN or SiO ２ In particular, when the insulating film 110 is made of SiN, it contributes to suppressing the penetration of moisture from the outside.

[0053] (Anode Electrode) The anode electrode 111 is, for example, configured to include a non-alloy metal film. Specifically, the anode electrode 111 has a laminated structure in which, for example, a Ti layer and an Au layer are laminated in this order from the second contact layer 109 side. Note that the anode electrode 111 may further have a Pt layer laminated on the Au layer to improve solderability. For example, the anode electrode 111 is electrically connected to the anode terminal 15b of the mounting substrate 15 via a first bump B1 (see FIGS. 7 and 8 ).

[0054] The cathode electrode 112 serving as an intermediate electrode is, for example, made of an alloy. Specifically, the cathode electrode 112 has a layered structure in which, for example, an AuGe layer, a Ni layer, and an Au layer are layered in this order from the first contact layer 102 side.

[0055] (Cathode Wiring) The cathode wiring 113 is made of, for example, Au plating, Ag plating, Al plating, etc. The thickness of the cathode wiring 113 is preferably a thickness that can sufficiently suppress voltage drop. As an example, the cathode wiring 113 is electrically connected to the cathode terminal 15c of the mounting substrate 15 via the second bump B2 (see FIGS. 7 and 8).

[0056] (Bumps) Each of the first and second bumps B1 and B2 is a conductive bump having electrical conductivity, and is made of a metal such as Ag, Au, Cu, or Ni, or a Pb-free solder such as AgSn, AuSn, CuSn, NiSn, or CuNiSn.

[0057] 7 and 8, the mounting substrate 15 (e.g., a laser driver) includes, as an example, a semiconductor substrate 15a (e.g., a p-type semiconductor substrate), nMOSs electrically connected to each light-emitting element unit LE provided on the semiconductor substrate 15a, a gate voltage control unit, and a current source. Each nMOS has a source connected to an anode terminal 15b of the mounting substrate 15, a drain connected to the current source, and a gate voltage (pulse voltage) applied to its gate from the gate voltage control unit. When a gate voltage is applied to each nMOS, it generates a drive pulse that causes the corresponding light-emitting element unit LE to emit or extinguish light, and applies the drive pulse to the light-emitting element unit LE. Examples of the semiconductor substrate 21 include a Si substrate, a Ge substrate, an SOI substrate, and a GOI substrate.

[0058] (Optical element portion) Fig. 5 is a diagram showing an irradiation pattern of photonic crystal surface light emitting device 10 according to Example 1 of an embodiment of the present technology. Fig. 6A is a diagram (corresponding to Fig. 1 ) showing emission directions of first and second elements E1 and E2 of photonic crystal surface light emitting device 10 according to Example 1 of an embodiment of the present technology. Fig. 6B is a diagram (corresponding to Fig. 2 ) showing emission directions of third and fourth elements E3 and E4 of photonic crystal surface light emitting device 10 according to Example 1 of an embodiment of the present technology.

[0059] Here, the first to fourth light-emitting element units LE1 to LE4 emit light in the same light-emitting pattern. That is, each light-emitting element unit LE has substantially the same photonic crystal (modified refractive index periodic structure 106a) in the photonic crystal layer 106. The photonic crystal is designed so that the emitted light pattern ELP is a spot pattern (see FIG. 5 ) in which a plurality of light spots (spot-like non-light) are arranged in a matrix (e.g., a 7×4 matrix arrangement).

[0060] As described above, each optical element portion 200 is, for example, a prism. The material of the prism is, for example, glass, resin, etc. The shape of the prism in plan view is polygonal, for example, rectangular. It is preferable that an anti-reflection film is provided on the light-emitting surface ES of the prism. The anti-reflection film may be, for example, a single-layer dielectric film, or a plurality of dielectric films (for example, SiO ２The insulating film may be a laminate of a silicon dioxide film, a silicon nitride film, a silicon dioxide ...

[0061] Each optical element section 200 controls the chief ray direction PR of the emitted light EL. Specifically, each optical element section 200 tilts the chief ray direction PR of the emitted light EL with respect to the stacking direction (substrate normal direction) of the active layer 104 and the photonic crystal layer 106 (see FIGS. 6A and 6B ).

[0062] Each optical element unit 200 controls the principal ray direction PR of the output light EL so that the output light pattern ELP, which is the pattern (more specifically, the far-field pattern) of the output light EL, is asymmetric with respect to a point C' (see FIG. 5 ), which corresponds to the center C (see FIG. 1 ) of the modified refractive index periodic structure 106a (photonic crystal) of the photonic crystal layer 106. Here, each output light pattern ELP is a spot pattern (matrix spot pattern) in which multiple (e.g., 28) light spots (spot-like light) are arranged in a matrix (e.g., a 7×4 matrix) within one of four divided rectangular areas obtained by dividing a rectangular area in which an irradiation pattern ELP1 can be generated (e.g., a 2×2 matrix) (see FIG. 5 ). Here, the term "spot" refers to a spot with a relatively large diameter.

[0063] Here, the rectangular area in which the irradiation pattern ELP1 can be generated is assumed to be the FOI (Field of Illumination) of a wide-angle camera with a screen aspect ratio (length:width) of 9:16, and the irradiation pattern ELP1 is a pattern in which light spots are uniformly arranged over the entire rectangular area.

[0064] More specifically, as shown in Figures 5, 6A, and 6B, an output light pattern ELP-A of output light EL-A from the first optical element unit 200A, an output light pattern ELP-B of output light EL-B from the second optical element unit 200B, an output light pattern ELP-C of output light EL-C from the third optical element unit 200C, and an output light pattern ELP-D of output light EL-D from the fourth optical element unit 200D are two-dimensionally arranged (e.g., a matrix arrangement) to form a single irradiation pattern ELP1 as a whole. The output light pattern ELP-A of the first optical element unit 200A is located in the upper left of the matrix arrangement in Figure 5. The output light pattern ELP-B of the second optical element unit 200B is located in the upper right of the matrix arrangement in Figure 5. The output light pattern ELP-C of the third optical element unit 200C is located in the lower right of the matrix arrangement in Figure 5. The emitted light pattern ELP-D of the fourth optical element unit 200D is located at the bottom left of the matrix arrangement in FIG.

[0065] The prisms serving as the optical element units 200 tilt the chief ray directions of the light from the corresponding light-emitting element units LE with respect to the stacking direction (the substrate normal direction) (see FIGS. 6A and 6B). The prisms serving as the optical element units 200 control the chief ray directions of the light from the corresponding light-emitting element units LE so that they are non-parallel to each other (see FIGS. 6A and 6B).

[0066] The exit surface ES of the prism serving as each optical element unit 200 is inclined with respect to the stacking direction (the direction normal to the substrate) (see FIGS. 1 and 2). As an example, the exit surface ES of each of the first to fourth optical element units 200A to 200D is inclined so as to gradually decrease in height from the outer periphery of the array toward the array center AC of an optical element unit array (see FIG. 3) in which the first to fourth optical element units 200A to 200D are arranged two-dimensionally (e.g., in a matrix arrangement) (see FIGS. 1 to 3). In FIG. 3, the inclination of the exit surface ES of each optical element unit 200 is represented by a shade of color, with the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0067] Here, the exit surfaces ES of the optical element sections 200 have the same inclination angle (prism angle: apex angle of the prism) with respect to the substrate normal direction, but differ in inclination direction with respect to the substrate normal direction.

[0068] As shown in FIG. 6A , the prism serving as the first optical element unit 200A controls the chief ray direction of light from the corresponding first light-emitting element unit LE1 to set the chief ray direction of the output light EL-A to a chief ray direction PR-A tilted by an angle θ (output angle α) relative to the substrate normal in a direction including a leftward component and a forward component in FIG. 6A with respect to the substrate normal. The chief ray direction PR-A is a direction toward the center of the output light pattern ELP-A (see FIG. 5 ). Here, the tilt directions of the chief ray direction PR-A (horizontal tilt angle, vertical tilt angle) are (−26.6°, +16°). Note that in FIG. 6A , a leftward tilt of the horizontal tilt angle is negative and a rightward tilt is positive, and a vertical tilt angle (a tilt angle perpendicular to the plane of the paper) is positive when tilted toward the plane of the paper and negative when tilted toward the plane of the paper (the same applies below).

[0069] As shown in FIG. 6A , the prism serving as the second optical element unit 200B controls the chief ray direction of light from the corresponding second light-emitting element unit LE2 to set the chief ray direction of output light EL-B to a chief ray direction PR-B that is tilted by an angle θ (output angle α) with respect to the substrate normal in a direction that includes a rightward component in FIG. 6A and a component toward the front of the page. The chief ray direction PR-B is a direction toward the center of the output light pattern ELP-B (see FIG. 5 ). In this example, the tilt directions of the chief ray direction PR-B (horizontal tilt angle, vertical tilt angle) are (+26.6°, +16°).

[0070] As shown in FIG. 6B , the prism serving as the third optical element unit 200C controls the chief ray direction of the light from the corresponding third light-emitting element unit LE3 to set the chief ray direction of the output light EL-C to a chief ray direction PR-C tilted by an angle θ (output angle α) relative to the substrate normal in a direction including a rightward component and a component toward the depth of the page in FIG. 6B . The chief ray direction PR-C is a direction toward the center of the output light pattern ELP-C (see FIG. 5 ). Here, the tilt directions of the chief ray direction PR-B (horizontal tilt angle, vertical tilt angle) are (+26.6°, −16°). Note that in FIG. 6B , a horizontal tilt angle is negative when tilted to the left and positive when tilted to the right, and a vertical tilt angle (a tilt angle perpendicular to the page) is positive when tilted toward the front of the page and negative when tilted toward the depth of the page (the same applies below).

[0071] As shown in FIG. 6B , the prism serving as the fourth optical element unit 200D controls the chief ray direction of light from the corresponding fourth light-emitting element unit LE4 to set the chief ray direction of the output light EL-D to a chief ray direction PR-D that is tilted by an angle θ (output angle α) with respect to the substrate normal in a direction that includes a leftward component in FIG. 6B and a component toward the depth of the page. The chief ray direction PR-D is a direction toward the center of the output light pattern ELP-D (see FIG. 5 ). Here, the tilt directions of the chief ray direction PR-D (horizontal tilt angle, vertical tilt angle) are (−26.6°, −16°).

[0072] As can be seen from the above description, the photonic crystal surface light emitting device 10 can selectively project light onto any (e.g., desired) irradiation area, thereby selectively generating at least one of the four emission light patterns ELP-A, ELP-B, ELP-C, and ELP-D, regardless of the emission constraints of the photonic crystal. That is, it is possible to generate an emission light pattern by emitting light onto the entire rectangular area (an area consisting of four divided rectangular areas arranged in a 2x2 matrix) in which the irradiation pattern ELP1 can be generated. It is also possible to generate an emission light pattern by emitting light onto a portion of the four divided rectangular areas. Therefore, for example, to save power consumption, it is possible to generate an emission light pattern only for the necessary divided rectangular areas of the rectangular area. As described above, the photonic crystal surface light emitting device 10 allows for a high degree of freedom in selecting the irradiation area of ​​the emission light.

[0073] (Prism parameters) Fig. 62 is a diagram for explaining how to find the prism parameters. As shown in Fig. 62, the prism angle θ0 is calculated according to the law of refraction, n0·sinθ 0 = n1 sinθ1, (where n0 is the refractive index of the substrate, n1 is the refractive index of air, θ0 is the angle of incidence of light onto the prism, and θ1 is the angle of refraction of light at the prism), so θ 0 = sin -1 (n1 / n0 sinθ1). The exit angle α of the prism can be calculated as α = θ1 - θ0.

[0074] <Operation of Photonic Crystal Surface Light Emitting Device> The operation of photonic crystal surface light emitting device 10 will be described below with reference to Figures 1, 7, 8, etc. In photonic crystal surface light emitting device 10, when a gate voltage (pulse voltage) is applied to at least one nMOS on mounting substrate 15, a current pulse is generated in the nMOS by a current from the anode side of mounting substrate 15, and this current pulse is applied to the light emitting element unit LE connected to the nMOS. The current pulse applied to the light emitting element unit LE is injected into active layer 104 via anode electrode 111, second contact layer 109, reflecting mirror 108, second cladding layer 107, and photonic crystal layer 106, in this order. At this time, active layer 104 emits light, and the light forms a standing wave in the in-plane direction within photonic crystal layer 106. When the resonance condition is satisfied, light is emitted from photonic crystal layer 106 toward substrate 101 and toward the opposite side from substrate 101. The light emitted toward the substrate 101 side is refracted at the interface between the substrate 101 and the optical element unit 200, propagates within the optical element unit 200, refracts at the interface between the optical element unit 200 and air (exit surface ES), and is emitted as output light EL. The light emitted toward the opposite side from the substrate 101 side is reflected by the reflecting mirror 108 toward the substrate 101 side, refracts at the interface between the substrate 101 and the optical element unit 200, propagates within the optical element unit 200, refracts at the interface between the optical element unit 200 and air (exit surface ES), and is emitted as output light EL (see FIGS. 6A and 6B ). The current that has passed through the active layer 104 flows through the first cladding layer 103, the first contact layer 102, the cathode electrode 112, and the cathode wiring 113, in this order, and is output to the cathode side of the mounting substrate 15.

[0075] <<Method of Manufacturing Photonic Crystal Surface Emitting Device and Light-Emitting Device>> A method of manufacturing the photonic crystal surface emitting device 10 and the light-emitting device 1 will be described below with reference to the flowchart in FIG. 9 and the like. For convenience, the cross-sectional views (manufacturing process diagrams) of each process in FIGS. 10 to 17 show only a portion corresponding to one half of the photonic crystal surface emitting device 10. The overall process begins with a semiconductor manufacturing method using semiconductor manufacturing equipment, in which multiple photonic crystal surface emitting devices 10 are simultaneously produced on a single wafer (hereinafter referred to as "substrate 101" for convenience) that serves as the base material for the substrate 101. Next, the multiple photonic crystal surface emitting devices 10 that are connected together are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped photonic crystal surface emitting devices 10.

[0076] In the first step S1, a stack is produced (see FIG. 10 ). Specifically, a stack is produced by stacking a first contact layer 102, a first cladding layer 103, an active layer 104, and a base material 106BM of a photonic crystal layer 106 in this order on a substrate 101 (e.g., an n-GaAs substrate, an SI-GaAs substrate, etc.) by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). Compound semiconductor raw materials include, for example, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH). ３ ) gas is used, and the source of the donor impurity is, for example, disilane (Si ２ H ６ ) is used, and the raw material of the acceptor impurity is, for example, carbon tetrabromide (CBr ４ ) is used.

[0077] In the next step S2, the photonic crystal layer 106 is formed (see FIG. 11 ). Specifically, a resist pattern for forming the modified refractive index periodic structure 106a of the photonic crystal layer 106 is formed on the stack (on the base material 106BM of the photonic crystal layer 106) by photolithography, and the base material 106BM is etched to a predetermined depth using the resist pattern as a mask, thereby forming the modified refractive index periodic structure 106a on the base portion 106b. At this time, it is preferable to use RIE (Reactive Ion Etching) using, for example, a Cl-based gas. The resist pattern is then removed.

[0078] In the next step S3, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated (see FIG. 12). Specifically, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated in this order by another epitaxial growth on the laminate (see FIG. 11) on which photonic crystal layer 106 has been formed.

[0079] In the next step S4, the light emitting mesa LM and the dummy mesa DM are formed (see FIG. 13). Specifically, a resist pattern for forming the light emitting mesa LM and the dummy mesa DM is formed on the stacked body (see FIG. 12) by photolithography, and the stacked body is etched by dry etching or wet etching using the resist pattern as a mask. The etching depth here is set to, for example, until the first contact layer 102 is exposed. The resist pattern is then removed.

[0080] In the next step S5, the anode electrode 111 and the cathode electrode 112 are formed (see FIG. 14 ). Specifically, the anode electrode 111 is formed on the center of the top of the light-emitting mesa LM (more specifically, the second contact layer 109) by, for example, a lift-off method. The cathode electrode 112 is formed on the region of the first contact layer 102 between the region where the light-emitting mesa LM protrudes and the region where the dummy mesa DM protrudes by, for example, a lift-off method. The electrode materials for the anode electrode 111 and the cathode electrode 112 are formed by, for example, evaporation, sputtering, or the like.

[0081] In the next step S6, the insulating film 110 is formed (see FIG. 15 ). Specifically, first, the insulating film 110 is formed over the entire surface of the stack (see FIG. 14 ) on which the anode electrode 111 and the cathode electrode 112 are formed, for example, by CVD (Chemical Vapor Deposition), sputtering, evaporation, or the like. Next, the insulating film 110 covering the anode electrode 111 and the cathode electrode 112 is removed by photolithography and etching to expose the anode electrode 111 and the cathode electrode 112.

[0082] Alternatively, instead of steps S5 and S6, an insulating film 110 may be formed before the anode electrode 111 and the cathode electrode 112 are formed on the laminate, and contact holes for forming the anode electrode 111 and the cathode electrode 112 may be formed in the insulating film 110, and electrodes corresponding to each contact hole may be formed by, for example, lift-off.

[0083] In the next step S7, the cathode wiring 113 is formed (see FIG. 16 ). Specifically, the cathode wiring 113 is formed by, for example, plating so that one end contacts the cathode electrode 112, the other end covers the top of the dummy mesa DM via the insulating film 110, and the middle part covers the side of the dummy mesa DM via the insulating film 110. Note that, prior to plating, it is preferable to form a seed layer in the area to be plated.

[0084] In the final step S8, a prism is formed as the optical element portion 200 (see FIG. 17 ). Specifically, first, the rear surface of the substrate 101 is ground to a thin film using, for example, a grinder or a CMP (Chemical Mechanical Polisher) device. Next, a film of, for example, a transparent resin material is formed on the rear surface of the substrate 101 by vapor deposition, sputtering, or the like, and a prism structure is formed in the transparent resin material by, for example, grayscale lithography. More specifically, a three-dimensional prism structure is formed on the rear surface of the substrate 101 using positive resist, and then the three-dimensional prism structure is transferred onto the substrate 101 by reactive ion etching or the like.

[0085] Thereafter, the substrate 101 is diced to obtain a plurality of chip-shaped photonic crystal surface light emitting devices 10. Note that, before dicing, it is preferable to remove the portion of the insulating film 110 to be diced. Note that, before dicing, it is preferable to form an anti-reflection film on the light emitting surface of the prism serving as the optical element portion 200.

[0086] The photonic crystal surface light emitting element 10 manufactured as described above is flip-chip mounted on a mounting substrate 15 (see FIGS. 7 and 8 ). Specifically, first, a first bump B1 is attached to the anode terminal 15b of the mounting substrate 15, and a second bump B2 is attached to the cathode terminal 15c. Next, the photonic crystal surface light emitting element 10 and the mounting substrate 15 are aligned so that the anode electrode 111 faces the first bump B1 and the cathode wiring 113 faces the second bump B2. Next, the photonic crystal surface light emitting element 10 and the mounting substrate 15 are thermocompression bonded (bonded by applying pressure while heating) via the first and second bumps B1 and B2. As a result, the photonic crystal surface light emitting element 10 and the mounting substrate 15 are electrically and mechanically connected via the first and second bumps B1 and B2. In this manner, the light emitting device 1 is manufactured.

[0087] Here, each bump is attached to the mounting substrate 15 side, but each bump may be attached to the photonic crystal surface light-emitting element 10 side, or bumps (of the same material or different materials) may be attached to both the mounting substrate 15 side and the photonic crystal surface light-emitting element 10 side.

[0088] <Effects of Photonic Crystal Surface Light Emitting Device and Light Emitting Device> Effects of the photonic crystal surface light emitting device 10 and the light emitting device 1 according to Example 1 of an embodiment of the present technology will be described below.

[0089] The photonic crystal surface light emitting device 10 has at least one (e.g., four) element E including a light emitting element section LE including an active layer 104 and a photonic crystal layer 106 stacked on top of each other, and an optical element section 200 provided on the emission side of the light emitting element section LE.

[0090] In the photonic crystal surface light emitting element 10, light (e.g., multiple light beams) from the light emitting element section LE can be controlled (e.g., refracted) by the optical element section 200 to irradiate any (e.g., desired) area with light (e.g., light whose principal ray direction is inclined with respect to the substrate normal direction).

[0091] As a result, photonic crystal surface light emitting device 10 can provide a photonic crystal surface light emitting device that allows for a high degree of freedom in selecting an irradiation area.

[0092] That is, the photonic crystal surface light emitting device 10 can irradiate light only onto desired areas, i.e., can avoid irradiating unnecessary areas with light, thereby making it possible to improve energy efficiency.

[0093] On the other hand, conventional PCSELs generate an emission light pattern that is point-symmetric with respect to the substrate normal direction (zero-order light), which inevitably generates not only an arbitrary (e.g., desired) illumination area, but also illumination areas that are point-symmetric with the illumination area (unnecessary illumination areas). For this reason, for example, in detecting moving objects or monitoring feature points, unnecessary areas are also illuminated, resulting in low energy efficiency.

[0094] (Comparative Example) Fig. 54 is a cross-sectional view of photonic crystal surface light emitting device 10C according to a comparative example. Fig. 55 is a plan view of photonic crystal surface light emitting device 10C according to a comparative example. Fig. 54 is a cross-sectional view taken along line 54-54 in Fig. 55. Fig. 56 is a diagram showing the irradiation pattern of photonic crystal surface light emitting device 10C according to a comparative example. Fig. 57A is a diagram showing the emission directions of first and second elements of photonic crystal surface light emitting device 10C according to a comparative example. Fig. 57B is a diagram showing the emission directions of third and fourth elements of photonic crystal surface light emitting device 10C according to a comparative example.

[0095] As shown in Figures 54 and 55, the photonic crystal surface light emitting device 10C of the comparative example has the same configuration as the photonic crystal surface light emitting device 10 of Example 1, except that it does not have an optical element section 200.

[0096] As shown in FIG. 56, the irradiation pattern ELP' and the emitted light pattern of the photonic crystal surface light emitting device 10C are point-symmetrical with respect to the center.

[0097] As shown in Figure 57A, in the photonic crystal surface light emitting element 10C, both the chief ray direction PR-A' of the emitted light EL-A' from the first light emitting element element LE1' and the chief ray direction PR-B' of the emitted light EL-B' from the second light emitting element element LE2' coincide with the substrate normal direction.

[0098] As shown in Figure 57B, in the photonic crystal surface light emitting element 10C, both the chief ray direction PR-C' of the emitted light EL-C' from the third light emitting element element LE3' and the chief ray direction PR-D' of the emitted light EL-D' from the fourth light emitting element element LE4' coincide with the substrate normal direction.

[0099] 2. Photonic Crystal Surface Light Emitting Device According to Example 2 of an Embodiment of the Present Technology> Fig. 18 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology. Fig. 19 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology. Fig. 20 is a plan view of the photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology. Fig. 18 is a cross-sectional view taken along line 18-18 of Fig. 20. Fig. 19 is a cross-sectional view taken along line 19-19 of Fig. 20. Fig. 21 is a diagram showing an irradiation pattern of the photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology. Fig. 22A is a diagram showing emission directions of first and second elements of the photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology. Fig. 22B is a diagram showing emission directions of third and fourth elements of the photonic crystal surface light emitting device 20 according to Example 2 of an embodiment of the present technology.

[0100] The photonic crystal surface light emitting device 20 according to the second embodiment has a configuration generally similar to that of the photonic crystal surface light emitting device 10 according to the first embodiment, except that the configuration of the optical element portion array is different.

[0101] In the photonic crystal surface light emitting element 20, the first to fourth light emitting element units LE1 to LE4 emit light in the same light emission pattern. That is, each light emitting element unit LE has substantially the same photonic crystal (modified refractive index periodic structure 106a) in the photonic crystal layer 106. The photonic crystal is designed so that each output light pattern ELP of the irradiation pattern ELP2 is a vertically elongated strip-shaped pattern (see FIG. 21).

[0102] In the photonic crystal surface light emitting device 20, as shown in Figure 21 as an example, each emission light pattern ELP is a vertically elongated stripe pattern that is placed in one of eight vertically elongated rectangular areas obtained by dividing (e.g., equally dividing) a rectangular area in which the irradiation pattern ELP2 can be generated horizontally (in the lateral direction) into eight parts, and a stripe pattern is formed by the eight emission light patterns ELP (vertical stripe patterns).

[0103] Here, the rectangular area in which the irradiation pattern ELP2 can be generated is assumed to be the FOI (Field of Illumination) of a wide-angle camera with a screen aspect ratio (height:width) of 9:16, and the irradiation pattern ELP2 is a stripe pattern in which vertically elongated band-shaped patterns are arranged horizontally across the entire rectangular area.

[0104] As shown in Figures 21 and 22, the vertically elongated band-shaped emission light pattern ELP-A1 of the emission light EL-A1 from the first optical element unit 200A, the vertically elongated band-shaped emission light pattern ELP-B1 of the emission light EL-B1 from the second optical element unit 200B, the vertically elongated band-shaped emission light pattern ELP-C1 of the emission light EL-C1 from the third optical element unit 200C, and the vertically elongated band-shaped emission light pattern ELP-D1 of the emission light EL-D1 from the fourth optical element unit 200D are arranged one-dimensionally in this order horizontally from left to right, and as a whole form the left half of the irradiation pattern ELP2.

[0105] As an example, a vertically elongated band-shaped emission light pattern ELP-A2 of the emission light EL-A2 from the first optical element unit 200A, a vertically elongated band-shaped emission light pattern ELP-B2 of the emission light EL-B2 from the second optical element unit 200B, a vertically elongated band-shaped emission light pattern ELP-C2 of the emission light EL-C2 from the third optical element unit 200C, and a vertically elongated band-shaped emission light pattern ELP-D2 of the emission light EL-D2 from the fourth optical element unit 200D are arranged one-dimensionally in this order horizontally from left to right, and as a whole form the right half of the irradiation pattern ELP2.

[0106] 22A and 22B , the prisms serving as the optical element units 200 tilt the chief ray directions PR of the light from the corresponding light-emitting element units LE with respect to the stacking direction (the direction normal to the substrate). The prisms serving as the optical element units 200 control the chief ray directions PR of the light from the corresponding light-emitting element units LE to be non-parallel to each other.

[0107] The exit surface ES of the prism serving as each optical element unit 200 is inclined with respect to the stacking direction (the substrate normal direction) (see FIGS. 18 to 20). As an example, the exit surface ES of each of the first and second optical element units 200A and 200B is inclined so as to gradually decrease in height from left to right (see FIGS. 18 and 20). As an example, the exit surface ES of each of the third and fourth optical element units 200C and 200D is inclined so as to gradually increase in height from left to right (see FIGS. 19 and 20). In FIG. 20, the inclination of the exit surface ES of each optical element unit 200 is represented by the shade of color, with the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0108] Here, the exit surfaces ES of the first and fourth optical element units 200A and 200D have the same inclination angle (prism angle: prism apex angle) with respect to the substrate normal direction, but are inclined in different directions with respect to the substrate normal direction (more specifically, they are line-symmetric with respect to the substrate normal direction). The exit surfaces ES of the second and third optical element units 200B and 200C have the same inclination angle (prism angle) with respect to the substrate normal direction, but are inclined in different directions with respect to the substrate normal direction (more specifically, they are line-symmetric with respect to the substrate normal direction). The prism angles of the first and fourth optical element units 200A and 200D are larger than the prism angles of the second and third optical element units 200C and 200D.

[0109] As shown in FIG. 22A , the prism serving as the first optical element unit 200A controls the chief ray direction of light from the corresponding first light-emitting element unit LE1, so that the chief ray direction of the output light EL-A, including the output lights EL-A1 and EL-A2, becomes a chief ray direction PR-A tilted at an angle θ1 to the left in FIG. 22A with respect to the substrate normal. The chief ray direction PR-A is a direction toward the center of the output light pattern ELP-C1 (see FIG. 21 ). Here, the inclination directions of the chief ray direction PR-A with respect to the substrate normal (horizontal inclination angle θ1, vertical inclination angle) are (−19.8°, 0°). Note that in FIG. 22A , a leftward tilt of the horizontal inclination angle is negative and a rightward tilt is positive, and a vertical inclination angle (a tilt angle perpendicular to the paper surface) is positive when tilted toward the paper surface and negative when tilted toward the paper surface (the same applies below).

[0110] As shown in FIG. 22A , the prism serving as the second optical element unit 200B controls the chief ray direction of light from the corresponding second light-emitting element unit LE2, so that the chief ray direction of output light EL-B, including output light EL-B1 and EL-B2, becomes chief ray direction PR-B, which is tilted to the left in FIG. 22A by an angle θ2 (<θ1) with respect to the substrate normal direction. The chief ray direction PR-B is a direction toward the center of the output light pattern ELP-D1 (see FIG. 21 ). Here, the tilt directions of the chief ray direction PR-B (horizontal tilt angle θ2, vertical tilt angle) are (−6.6°, 0°).

[0111] As shown in FIG. 22B , the prism serving as the third optical element unit 200C controls the chief ray direction of the light from the corresponding third light-emitting element unit LE3, so that the chief ray direction of the output light EL-C, including the output lights EL-C1 and EL-C2, becomes a chief ray direction PR-C that is tilted to the right in FIG. 22B by an angle θ2 (<θ1) with respect to the substrate normal. The chief ray direction PR-C is a direction toward the center of the output light pattern ELP-A2 (see FIG. 21 ). Here, the inclination directions of the chief ray direction PR-C (horizontal inclination angle θ2, vertical inclination angle) are (+6.6°, 0°). Note that in FIG. 22B , a horizontal inclination angle tilted to the left is negative and a vertical inclination angle tilted to the right is positive, and a vertical inclination angle (a tilt angle perpendicular to the paper surface) tilted toward the paper surface is positive and toward the back of the paper surface is negative (the same applies below).

[0112] As shown in FIG. 22B , the prism serving as the fourth optical element unit 200D controls the chief ray direction of light from the corresponding fourth light-emitting element unit LE4, so that the chief ray direction of output light EL-D, including output light EL-D1 and EL-D2, becomes a chief ray direction PR-D that is tilted by an angle θ1 to the right in FIG. 22B with respect to the substrate normal direction. The chief ray direction PR-D is a direction that passes through the center of the output light pattern ELP-B2 (see FIG. 21 ). Here, the tilt directions of the chief ray direction PR-D (horizontal tilt angle θ1, vertical tilt angle) are (+19.8°, 0°).

[0113] The photonic crystal surface light emitting device 20 provides effects generally similar to those of the photonic crystal surface light emitting device 10 of Example 1, and since the irradiation pattern ELP2 is a stripe pattern, it is suitable for use as a light source for, for example, a LiDAR scanner.

[0114] 23 is a cross-sectional view (part 1) of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology. FIG. 24 is a cross-sectional view (part 2) of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology. FIG. 25 is a plan view of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology. FIG. 23 is a cross-sectional view taken along line 23-23 of FIG. 25. FIG. 24 is a cross-sectional view taken along line 24-24 of FIG. 25. FIG. 26 is a diagram showing an irradiation pattern of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology. FIG. 27A is a diagram showing emission directions of first and second elements of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology. FIG. 27B is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light-emitting device 30 according to Example 3 of an embodiment of the present technology.

[0115] The photonic crystal surface light emitting device 30 according to the third embodiment has a configuration generally similar to that of the photonic crystal surface light emitting device 10 according to the first embodiment, except that the configuration of the optical element portion array is different.

[0116] In the photonic crystal surface light-emitting element 30, the first to fourth light-emitting element units LE1 to LE4 emit light in the same light-emitting pattern. That is, each light-emitting element unit LE has substantially the same photonic crystal (modified refractive index periodic structure 106a) in the photonic crystal layer 106. The photonic crystal is designed so that each output light pattern ELP of the irradiation pattern ELP3 is a pattern in which a plurality of light dots (dot-shaped light) are arranged in a matrix at intervals of one dot in the horizontal and vertical directions (see FIG. 26). Here, "dot" refers to a relatively small diameter.

[0117] In the photonic crystal surface light emitting device 30, as shown in Figure 26 as an example, each emitted light pattern ELP is a dot pattern (matrix dot pattern) in which multiple light dots are arranged in a matrix with one dot intervals in both the horizontal and vertical directions within a rectangular area in which an irradiation pattern ELP3 can be generated.

[0118] As shown in Figures 26 and 27, as an example, an output light pattern ELP-A of output light EL-A1 from the first optical element unit 200A, in which a plurality of light dots are arranged in a matrix, an output light pattern ELP-B of output light EL-B from the second optical element unit 200B, an output light pattern ELP-C of output light EL-C from the third optical element unit 200C, in which a plurality of light dots are arranged in a matrix, and an output light pattern ELP-D of output light EL-D from the fourth optical element unit 200D, in which a plurality of light dots are arranged in a matrix, are arranged (alternately arranged) so as to be shifted by one dot from each other in the horizontal or vertical direction and not overlap, thereby forming an irradiation pattern ELP3 in which a plurality of light dots are arranged at a high density overall.

[0119] Here, the rectangular area in which the irradiation pattern ELP3 can be generated is assumed to be the FOI (Field of Illumination) of a wide-angle camera with a screen aspect ratio (length:width) of 9:16, and the irradiation pattern ELP3 is a dot pattern in which multiple light dots are densely arranged in a matrix in the horizontal and vertical directions across the entire rectangular area.

[0120] 27A and 27B , the prisms serving as the optical element units 200 tilt the chief ray directions PR of the light from the corresponding light-emitting element units LE with respect to the stacking direction (the direction normal to the substrate). The prisms serving as the optical element units 200 control the chief ray directions PR of the light from the corresponding light-emitting element units LE to be non-parallel to each other.

[0121] The exit surface ES of the prism serving as the optical element unit 200 is inclined with respect to the stacking direction (the direction normal to the substrate) (see FIGS. 23 and 24). As an example, the exit surface ES of each of the first to fourth optical element units 200A to 200D is inclined so as to gradually decrease in height from the outer periphery of the array toward the array center AC of an optical element unit array (see FIG. 25) in which the first to fourth optical element units 200A to 200D are arranged two-dimensionally (e.g., in a matrix arrangement) (see FIGS. 23 to 25). In FIG. 25, the inclination of the exit surface ES of each optical element unit 200 is represented by a shade of color, with the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0122] Here, the exit surfaces ES of the optical element sections 200 have the same inclination angle (prism angle: apex angle of the prism) with respect to the substrate normal direction, but differ in inclination direction with respect to the substrate normal direction.

[0123] As shown in Fig. 27A , the prism serving as the first optical element unit 200A controls the chief ray direction of light from the corresponding first light-emitting element unit LE1 to set the chief ray direction of output light EL-A to a chief ray direction PR-A that is tilted by an angle θ with respect to the substrate normal in a direction that includes a leftward component in Fig. 27A and a component toward the front of the page. The chief ray direction PR-A is a direction toward the light dot ELP-C1 of the output light pattern ELP-C, which is located in the center of the irradiation pattern ELP3 (the area surrounded by the dashed-dotted line in Fig. 26 ). Here, the tilt directions (horizontal tilt angle, vertical tilt angle) of the chief ray direction PR-A with respect to the substrate normal are (-3.8°, +4°). However, in FIG. 27A, the horizontal tilt angle is negative when tilted to the left and positive when tilted to the right, and the vertical tilt angle (tilt angle perpendicular to the paper surface) is positive when tilted towards the front of the paper and negative when tilted towards the back of the paper (same below).

[0124] As shown in Fig. 27A , the prism serving as the second optical element unit 200B controls the chief ray direction of light from the corresponding second light-emitting element unit LE2 to set the chief ray direction of output light EL-B to a chief ray direction PR-B that is tilted by an angle θ with respect to the substrate normal in a direction that includes a rightward component in Fig. 27A and a component toward the front of the page. The chief ray direction PR-B is a direction toward the light dot ELP-D1 of the output light pattern ELP-D, which is located in the center of the irradiation pattern ELP3 (the area surrounded by the dashed-dotted line in Fig. 26 ). Here, the tilt directions of the chief ray direction PR-B (horizontal tilt angle, vertical tilt angle) are (+3.8°, +4°).

[0125] As shown in FIG. 27B , the prism serving as the third optical element unit 200C controls the chief ray direction of the light from the corresponding third light-emitting element unit LE3 to set the chief ray direction of the output light EL-C to a chief ray direction PR-C tilted by an angle θ relative to the substrate normal in a direction including a rightward component and a depthward component in FIG. 27B with respect to the substrate normal. The chief ray direction PR-C is directed toward the light dot ELP-A1 of the output light pattern ELP-A, which is located in the center of the irradiation pattern ELP3 (the area surrounded by the dashed-dotted line in FIG. 26 ). Here, the tilt directions of the chief ray direction PR-C (horizontal tilt angle, vertical tilt angle) are (+3.8°, −4°). Note that in FIG. 27B , a leftward tilt of the horizontal tilt angle is negative and a rightward tilt is positive, and a vertical tilt angle (a tilt angle perpendicular to the plane of ...

[0126] As shown in Fig. 27B , the prism serving as the fourth optical element unit 200D controls the chief ray direction of light from the corresponding fourth light-emitting element unit LE4 to set the chief ray direction of output light EL-D to a chief ray direction PR-D that is tilted by an angle θ with respect to the substrate normal in a direction that includes a leftward component in Fig. 27B and a component toward the depth of the page. The chief ray direction PR-D is directed toward the light dot ELP-B1 of the output light pattern ELP-B, which is located in the center of the irradiation pattern ELP3 (the area surrounded by the dashed-dotted line in Fig. 26 ). Here, the tilt directions of the chief ray direction PR-D (horizontal tilt angle, vertical tilt angle) are (-3.8°, -4°).

[0127] The photonic crystal surface light emitting device 30 achieves substantially the same effects as the photonic crystal surface light emitting device 10 according to the first embodiment, and the irradiation pattern ELP3 is a pattern in which light dots are densely arranged, consisting of a plurality of exit light patterns ELP (matrix dot patterns) alternately combined (without overlapping). This contributes to improving spatial resolution (angular resolution) when used in, for example, DToF (Direct Time Of Flight). This makes it possible to obtain HD (High Definition) or 4K image quality. On the other hand, if the irradiation pattern is composed of a single exit light pattern, the spatial resolution cannot be improved, making it difficult to obtain HD (High Definition) or 4K image quality.

[0128] 28 is a cross-sectional view (part 1) of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology. FIG. 29 is a cross-sectional view (part 2) of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology. FIG. 30 is a plan view of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology. FIG. 28 is a cross-sectional view taken along line 28-28 of FIG. 30. FIG. 29 is a cross-sectional view taken along line 29-29 of FIG. 30. FIG. 31 is a diagram showing an irradiation pattern of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology. FIG. 32A is a diagram showing emission directions of first and second elements of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology. FIG. 32B is a diagram showing emission directions of third and fourth elements of a photonic crystal surface light-emitting device 40 according to Example 4 of an embodiment of the present technology.

[0129] The photonic crystal surface light emitting device 40 according to the fourth embodiment has a configuration generally similar to that of the photonic crystal surface light emitting device 10 according to the first embodiment, except that the configuration of the optical element portion array is different.

[0130] In the photonic crystal surface light-emitting element 40, the first to fourth light-emitting element units LE1 to LE4 emit light in the same light-emitting pattern. That is, each light-emitting element unit LE has substantially the same photonic crystal (modified refractive index periodic structure 106a) in the photonic crystal layer 106. The photonic crystal is designed so that each output light pattern ELP of the irradiation pattern ELP4 is a pattern in which a plurality of light dots (dot-shaped light) are arranged in a matrix at intervals of half a dot in the horizontal and vertical directions (see FIG. 31). Here, "dot" means a relatively small diameter.

[0131] In the photonic crystal surface light emitting device 40, as shown in Figure 31 as an example, each emitted light pattern ELP is a dot pattern (matrix dot pattern) in which multiple light dots are arranged in a matrix so that they partially overlap (for example, 1 / 4 dot) in both the horizontal and vertical directions within a rectangular area in which an irradiation pattern ELP4 can be generated.

[0132] Here, it is preferable that the light emitting element units LE are designed so that the wavelengths and / or polarization directions of the light emitted from each light emitting element unit LE are different.

[0133] As shown in Figures 31, 32A and 32B, as an example, an output light pattern ELP-A of output light EL-A from the first optical element unit 200A, in which a plurality of light dots are arranged in a matrix, an output light pattern ELP-B of output light EL-B from the second optical element unit 200B, an output light pattern ELP-C of output light EL-C from the third optical element unit 200C, in which a plurality of light dots are arranged in a matrix, and an output light pattern ELP-D of output light EL-D from the fourth optical element unit 200D, in which a plurality of light dots are arranged in a matrix, are arranged so that they partially overlap each other in the horizontal or vertical direction (for example, by 1 / 4 dot), thereby forming an irradiation pattern ELP4 in which a plurality of light dots are arranged at an ultra-high density overall.

[0134] Here, the rectangular area in which the irradiation pattern ELP4 can be generated is assumed to be the FOI (Field of Illumination) of a wide-angle camera with a screen aspect ratio (height:width) of 9:16, and the irradiation pattern ELP4 is a dot pattern in which multiple light dots are arranged in a matrix at ultra-high density in the horizontal and vertical directions across the entire rectangular area.

[0135] 32A and 32B , the prisms serving as the optical element units 200 tilt the chief ray directions PR of the light from the corresponding light-emitting element units LE with respect to the stacking direction (the direction normal to the substrate). The prisms serving as the optical element units 200 control the chief ray directions PR of the light from the corresponding light-emitting element units LE to be non-parallel to each other.

[0136] The exit surface ES of the prism serving as the optical element unit 200 is inclined with respect to the stacking direction (the direction normal to the substrate) (see FIGS. 28 and 29). As an example, the exit surface ES of each of the first to fourth optical element units 200A to 200D is inclined so as to gradually decrease in height from the outer periphery of the array toward the array center AC of an optical element unit array (see FIG. 30) in which the first to fourth optical element units 200A to 200D are arranged two-dimensionally (e.g., in a matrix arrangement) (see FIGS. 28 to 30). In FIG. 30, the inclination of the exit surface ES of each optical element unit 200 is represented by a shade of color, with the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0137] Here, the exit surfaces ES of the optical element sections 200 have the same inclination angle (prism angle: apex angle of the prism) with respect to the substrate normal direction, but differ in inclination direction with respect to the substrate normal direction.

[0138] As shown in Fig. 32A , the prism serving as the first optical element unit 200A controls the chief ray direction of light from the corresponding first light-emitting element unit LE1 to set the chief ray direction of output light EL-A to a chief ray direction PR-A that is tilted by an angle θ with respect to the substrate normal in a direction that includes a leftward component in Fig. 32A and a component toward the front of the page. The chief ray direction PR-A is a direction toward the light dot ELP-C1 of the output light pattern ELP-C, which is located in the center of the irradiation pattern ELP4 (the area surrounded by the dashed-dotted line in Fig. 31 ). Here, the tilt directions (horizontal tilt angle, vertical tilt angle) of the chief ray direction PR-A with respect to the substrate normal are (-0.4°, +0.4°). However, in Figure 32A, the horizontal tilt angle is negative when tilted to the left and positive when tilted to the right, and the vertical tilt angle (tilt angle perpendicular to the paper surface) is positive when tilted towards the front of the paper and negative when tilted towards the back of the paper (the same applies below).

[0139] As shown in Fig. 32A , the prism serving as the second optical element unit 200B controls the chief ray direction of light from the corresponding second light-emitting element unit LE2 to set the chief ray direction of output light EL-B to a chief ray direction PR-B that is tilted by an angle θ with respect to the substrate normal in a direction that includes a rightward component in Fig. 32A and a component toward the front of the page. The chief ray direction PR-B is a direction toward the light dot ELP-D1 of the output light pattern ELP-D, which is located in the center of the irradiation pattern ELP4 (the area surrounded by the dashed-dotted line in Fig. 31 ). Here, the tilt directions of the chief ray direction PR-B (horizontal tilt angle, vertical tilt angle) are (+0.4°, +0.4°).

[0140] As shown in FIG. 32B , the prism serving as the third optical element unit 200C controls the chief ray direction of the light from the corresponding third light-emitting element unit LE3 to set the chief ray direction of the output light EL-C to a chief ray direction PR-C tilted by an angle θ relative to the substrate normal in a direction including a rightward component and a component toward the depth of the page in FIG. 32B . The chief ray direction PR-C is directed toward the light dot ELP-A1 of the output light pattern ELP-A, which is located in the center of the irradiation pattern ELP4 (the area surrounded by the dashed-dotted line in FIG. 31 ). Here, the tilt directions of the chief ray direction PR-C (horizontal tilt angle, vertical tilt angle) are (+0.4°, −0.4°). Note that in FIG. 32B , a horizontal tilt angle toward the left is negative and a vertical tilt is positive, and a vertical tilt angle (a tilt angle perpendicular to the page) toward the front of the page is positive and toward the depth of the page is negative (the same applies below).

[0141] As shown in FIG. 32B , the prism serving as the fourth optical element unit 200D controls the chief ray direction of light from the corresponding fourth light-emitting element unit LE4 to set the chief ray direction of output light EL-D to a chief ray direction PR-D that is tilted by an angle θ with respect to the substrate normal in a direction that includes a leftward component in FIG. 32B and a component toward the depth of the page. The chief ray direction PR-D is a direction toward the light dot ELP-B1 of the output light pattern ELP-B, which is located in the center of the irradiation pattern ELP4 (the area surrounded by the dashed-dotted line in FIG. 31 ). Here, the tilt directions of the chief ray direction PR-D (horizontal tilt angle, vertical tilt angle) are (−0.4°, −0.4°).

[0142] The photonic crystal surface light emitting device 40 achieves substantially the same effects as the photonic crystal surface light emitting device 10 according to the first embodiment, and the irradiation pattern ELP4 is a pattern in which light dots are arranged at an ultra-high density, where multiple exit light patterns ELP (matrix dot patterns) are combined so that they partially overlap. This significantly improves spatial resolution (angular resolution) when used in, for example, DToF. This makes it possible to obtain high-definition (HD) or 4K image quality. Furthermore, by differentiating the wavelength and / or polarization direction of the light generated by each light emitting element unit LE, adjacent light dots in the exit light pattern can be prevented from substantially overlapping, enabling flood illumination with reduced speckle.

[0143] 5. Photonic crystal surface light emitting device according to example 5 of an embodiment of the present technology> Fig. 33 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 34 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 35 is a plan view of a photonic crystal surface light emitting device 50 according to example 5 of an embodiment of the present technology. Fig. 33 is a cross-sectional view taken along line 33-33 in Fig. 35. Fig. 34 is a cross-sectional view taken along line 34-34 in Fig. 35.

[0144] 33 to 35, the photonic crystal surface light emitting device 50 according to Example 5 has the same configuration as the photonic crystal surface light emitting device 10 according to Example 1, except that the shape of each optical element portion 200 (e.g., prism) in plan view is circular. Note that the shape of each optical element portion 200 (e.g., prism) in plan view may be elliptical.

[0145] In FIG. 35, the inclination of the exit surface ES of each optical element portion 200 is represented by the shade of color, and the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0146] According to the photonic crystal surface light emitting device 50, the same effects as those of the photonic crystal surface light emitting device 10 according to the first embodiment can be obtained.

[0147] 6. Photonic crystal surface light emitting device according to example 6 of an embodiment of the present technology> Fig. 36 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 60 according to example 6 of an embodiment of the present technology. Fig. 37 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 60 according to example 6 of an embodiment of the present technology. Fig. 36 is a plan view of a photonic crystal surface light emitting device 60 according to example 6 of an embodiment of the present technology. Fig. 36 is a cross-sectional view taken along line 36-36 in Fig. 38. Fig. 37 is a cross-sectional view taken along line 37-37 in Fig. 38.

[0148] 36 to 38, the photonic crystal surface light emitting device 60 according to Example 6 has the same configuration as the photonic crystal surface light emitting device 10 according to Example 1, except that the shape of each optical element portion 200 (e.g., prism) in plan view is hexagonal (e.g., regular hexagonal). Note that the shape of each optical element portion 200 (e.g., prism) in plan view may be a polygon other than a hexagon.

[0149] In FIG. 38, the inclination of the exit surface ES of each optical element portion 200 is represented by the shade of color, and the darker the color, the lower the exit surface ES, and the lighter the color, the higher the exit surface ES.

[0150] In the photonic crystal surface light emitting device 60, as an example, an optical element unit pair consisting of first and fourth optical element units 200A, 200D arranged adjacent to each other and an optical element unit pair consisting of second and third optical element units 200C, 200D arranged adjacent to each other are arranged in a direction perpendicular to the arrangement direction of the optical element units in each optical element unit pair to form an optical element unit array. In the photonic crystal surface light emitting device 60, a plurality of (for example, four) light emitting element units LE form a light emitting element unit array corresponding to the optical element unit array.

[0151] According to the photonic crystal surface light emitting device 60, substantially the same effects as those of the photonic crystal surface light emitting device 10 according to the first embodiment can be obtained.

[0152] 7. Photonic Crystal Surface Light Emitting Device According to Example 7 of an Embodiment of the Present Technology> FIG. 39 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 70 according to Example 7 of an embodiment of the present technology. FIG. 40 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 70 according to Example 7 of an embodiment of the present technology. FIG. 41 is a cross-sectional view (part 3) of a photonic crystal surface light emitting device 70 according to Example 7 of an embodiment of the present technology. FIG. 42 is a plan view of a photonic crystal surface light emitting device 70 according to Example 7 of an embodiment of the present technology. FIG. 39 is a cross-sectional view taken along line 39-39 in FIG. 42 . FIG. 40 is a cross-sectional view taken along line 40-40 in FIG. 42 . FIG. 41 is a cross-sectional view taken along line 41-41 in FIG. 42 .

[0153] The photonic crystal surface light emitting device 70 of Example 7 has a configuration similar to that of the photonic crystal surface light emitting device 10 of Example 1, except that, as shown in Figures 39 to 42, it has a plurality of (e.g., seven) elements E, the optical element portions 200 (e.g., prisms) of the plurality of (e.g., seven) elements E are closely packed together in a hexagonal pattern to form an optical element portion array, and the light emitting element portions LE of the plurality of (e.g., seven) elements E form a light emitting element portion array corresponding to the optical element portion array.

[0154] As an example, the photonic crystal surface light emitting device 70 includes a plurality (e.g., seven) of optical element units 200 (e.g., optical element units 200A-200G), each of which has a hexagonal (e.g., regular hexagonal) shape in a plan view. As shown in Fig. 42, the optical element units 200A, 200E, 200B, 200C, 200G, and 200D are arranged in this order around the periphery of the array, and the optical element unit 200F is arranged in the center of the array. Of the plurality (e.g., seven) of optical element units 200, the optical element unit 200F has an exit surface perpendicular to the substrate normal direction, and controls the chief ray direction of light from the corresponding light emitting element unit LE to coincide with the substrate normal direction.

[0155] In FIG. 42, the inclination of the exit surface of each optical element portion 200 is represented by the shade of color, with the darker the color, the lower the exit surface, and the lighter the color, the higher the exit surface.

[0156] According to the photonic crystal surface light emitting device 70, substantially the same effects as those of the photonic crystal surface light emitting device 10 according to the first embodiment can be obtained.

[0157] 8. Photonic crystal surface light emitting device according to example 8 of an embodiment of the present technology> Fig. 43 is a cross-sectional view of a photonic crystal surface light emitting device 80 according to example 8 of an embodiment of the present technology. Fig. 44 is a plan view of a photonic crystal surface light emitting device 80 according to example 8 of an embodiment of the present technology. Fig. 43 is a cross-sectional view taken along line 43-43 of Fig. 44 .

[0158] The photonic crystal surface light emitting device 80 of Example 8 has a configuration similar to that of the photonic crystal surface light emitting device 10 of Example 1, except that, as shown in Figures 43 and 44, a plurality of (e.g., four) elements E are arranged in a one-dimensional manner, a plurality of (e.g., four) optical element sections 200 (e.g., prisms) each having a circular planar shape are arranged in a one-dimensional manner to form an optical element section array, and a plurality of (e.g., four) light emitting element sections LE form a light emitting element section array corresponding to the optical element section array.

[0159] In FIG. 44, the inclination of the exit surface of each optical element portion 200 is represented by the shade of color, with the darker the color, the lower the exit surface, and the lighter the color, the higher the exit surface.

[0160] According to the photonic crystal surface light emitting device 80, substantially the same effects as those of the photonic crystal surface light emitting device 10 according to the first embodiment can be obtained.

[0161] 9. Photonic Crystal Surface Light Emitting Device According to Example 9 of an Embodiment of the Present Technology> Fig. 45 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 90 according to Example 9 of an embodiment of the present technology. Fig. 46 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 90 according to Example 9 of an embodiment of the present technology. Fig. 47 is a plan view of a photonic crystal surface light emitting device 90 according to Example 9 of an embodiment of the present technology. Fig. 45 is a cross-sectional view taken along line 45-45 in Fig. 47 . Fig. 46 is a cross-sectional view taken along line 46-46 in Fig. 47 .

[0162] As shown in Figures 45 to 47, the photonic crystal surface light-emitting device 90 of Example 9 has a configuration similar to that of the photonic crystal surface light-emitting device 10 of Example 1, except that a rim portion RM is provided around the prism serving as the optical element portion 200.

[0163] In the photonic crystal surface light-emitting device 90, the rim portion RM is arranged in a circular (e.g., frame-like) shape to surround an optical element array in which multiple (e.g., four) optical element portions 200 are arranged two-dimensionally (e.g., in a matrix) (see Figure 47).

[0164] The rim portion RM is provided at the outer peripheral edge of each optical element portion 200 so as to protrude slightly above the optical element portion 200 (see Figures 45 and 46). Here, the rim portion RM is provided integrally with (made of the same material as) each optical element portion 200, but it may also be provided separately (made of the same material or a different material).

[0165] According to the photonic crystal surface light emitting device 90, a rim portion RM is provided around the periphery of the prism serving as the optical element portion 200, so that chipping or cracking of the prism edge can be suppressed during mounting on a mounting substrate or during transportation.

[0166] 10. Photonic crystal surface light emitting device according to example 10 of an embodiment of the present technology> Fig. 48 is a cross-sectional view (part 1) of photonic crystal surface light emitting device 100 according to example 10 of an embodiment of the present technology. Fig. 49 is a cross-sectional view (part 2) of photonic crystal surface light emitting device 100 according to example 10 of an embodiment of the present technology. Fig. 50 is a plan view of photonic crystal surface light emitting device 100 according to example 10 of an embodiment of the present technology. Fig. 48 is a cross-sectional view taken along line 48-48 in Fig. 50. Fig. 49 is a cross-sectional view taken along line 49-49 in Fig. 50.

[0167] The photonic crystal surface emitting device 100 of Example 10 has a configuration similar to that of the photonic crystal surface emitting device 90 of Example 9, except that there is a gap G between the prism as the optical element portion 200 and the rim portion RM, as shown in Figures 48 to 50.

[0168] The gap G is in a circumferential shape (for example, a frame shape) along the entire periphery of the optical element unit array in which a plurality of (for example, four) optical element units 200 are arranged two-dimensionally (for example, in a matrix arrangement).

[0169] According to the photonic crystal surface light-emitting device 100, there is a gap G between the prism as the optical element portion 200 and the rim portion RM, so that it is possible to protect the prism by preventing damage such as chipping or cracks that occurs in the rim portion RM from reaching the prism.

[0170] 11. Photonic crystal surface light emitting device according to example 11 of an embodiment of the present technology> Fig. 51 is a cross-sectional view (part 1) of a photonic crystal surface light emitting device 119 according to example 11 of an embodiment of the present technology. Fig. 52 is a cross-sectional view (part 2) of a photonic crystal surface light emitting device 119 according to example 11 of an embodiment of the present technology. Fig. 53 is a plan view of a photonic crystal surface light emitting device 119 according to example 11 of an embodiment of the present technology. Fig. 51 is a cross-sectional view taken along line 51-51 in Fig. 53. Fig. 52 is a cross-sectional view taken along line 52-52 in Fig. 53.

[0171] As shown in Figures 51 to 53, the photonic crystal surface light-emitting element 119 of Example 11 is a surface-emitting type, and has a configuration similar to that of the photonic crystal surface light-emitting element 10 of Example 1, except that an optical element section 200 is provided on the light-emitting mesa LM of each light-emitting element section LE.

[0172] In the photonic crystal surface light emitting device 119 , a reflector 108 (for example, an n-type semiconductor multilayer film reflector) is disposed between the first contact layer 102 and the first cladding layer 103 .

[0173] Here, the anode electrode 111 is provided in a circumferential shape (e.g., ring shape) on the light-emitting mesa LM. For example, two elongated cathode electrodes 112 are provided on the first contact layer 102 so as to sandwich an optical element array in which a plurality of optical element portions 200 are arranged two-dimensionally (e.g., in a matrix).

[0174] The photonic crystal surface light emitting element 119 is mounted on a mounting substrate (drive substrate or wiring substrate) with the junction facing up to form a light emitting device. The anode electrode 111 and the cathode electrode 112 are each electrically connected to the mounting substrate via bonding wires.

[0175] According to the photonic crystal surface light emitting device 119, it is possible to provide a surface-emitting photonic crystal surface emitting laser that can obtain substantially the same effects as the photonic crystal surface light emitting device 10 according to the first embodiment.

[0176] Incidentally, when a dot pattern (emitted light pattern) is generated by emitting a plurality of light beams under light emission control by the photonic crystal layer 106C, as in the photonic crystal surface light emitting device according to Comparative Example 1 shown in Fig. 94, the light forming each dot contains higher-order mode light HML (unwanted light) around fundamental mode light BML (used light), which may degrade the beam quality of the dot pattern. In Fig. 94, for each component of the photonic crystal surface light emitting device according to Comparative Example 1, the letter C is added to the reference numeral of the corresponding component of the photonic crystal surface light emitting device 10 according to Example 1.

[0177] Therefore, after extensive research, the inventors have succeeded in developing a technology that spatially separates useful light from unwanted light and suppresses degradation of the beam quality of the emitted light pattern by generating an emitted light pattern through light emission control using a metasurface included in the optical element section. Furthermore, the inventors have also succeeded in developing a technology that effectively reduces reflection at the interface between the metasurface and air. These technologies are the inventors' new findings. Below, we will explain examples that embody these new findings.

[0178] 12. Photonic crystal surface light emitting device according to example 12 of an embodiment of the present technology> Fig. 63 is a cross-sectional view of a photonic crystal surface light emitting device 120 according to example 12 of an embodiment of the present technology. Fig. 64 is a plan view of a metasurface MS12 of a photonic crystal surface light emitting device 120 according to example 12 of an embodiment of the present technology. Fig. 65 is a cross-sectional view showing a light emitting state of a photonic crystal surface light emitting device 120 according to example 12 of an embodiment of the present technology. Fig. 66 is a diagram showing an emitted light pattern (far-field pattern) of a photonic crystal surface light emitting device 120 according to example 12 of an embodiment of the present technology.

[0179] In the photonic crystal surface light-emitting device 120 of Example 12, as shown in Figure 63, the light-emitting device section LE is provided on the front side (one side, opposite the emission side) of the substrate 101, and the metasurface MS12 included in the optical element section is provided on the back side (other side, emission side) of the substrate 101.

[0180] The metasurface MS12 has a pillar group PG including multiple pillars P arranged two-dimensionally on a reference plane RP (e.g., the back surface of the substrate 101).

[0181] Here, the term "metasurface" can include only the group of pillars in a narrow sense, or can include elements other than the group of pillars in a broad sense. In this specification, the metasurface is described in a broad sense, but when the metasurface is interpreted in a narrow sense, elements other than the group of pillars can be considered as elements of the optical element portion other than the metasurface.

[0182] The metasurface MS12 has a partially discontinuous (intermittent) pillar arrangement (see FIG. 64). This allows the metasurface MS12 to split the light (approximately parallel light) from the light-emitting element section LE into multiple beams (approximately parallel light), as will be described in detail later (see FIG. 65). At this time, the light-emitting element section LE emits the light (approximately parallel light) in the stacking direction (e.g., upward) of the active layer 104 and the photonic crystal layer 106 (vertical emission).

[0183] The chief ray direction of at least one of the multiple beams split by the metasurface 12 is tilted with respect to the stacking direction of the active layer 104 and the photonic crystal layer 106 (see FIG. 65 ). More specifically, the multiple beams split by the metasurface 12 are radially emitted from the metasurface MS12 (see FIG. 65 ).

[0184] The light from the light-emitting element unit LE includes fundamental mode light BML (single mode light) and higher-order mode light HML surrounding the fundamental mode light BML (see Figure 65). The fundamental mode light BML is split into multiple first split light beams SL1 (used light) by the metasurface MS12. The higher-order mode light HML is emitted as second split light beams SL2 (unwanted light) that are spatially separated from the multiple first split light beams SL1 by the metasurface MS12.

[0185] In the photonic crystal surface light emitting device 120 configured as described above, the emitted light pattern (far field pattern) is a dot pattern dotP in which dots SL1-dot (used light) formed by each of the multiple first divided lights SL1 are arranged two-dimensionally (see Figure 66).

[0186] According to the photonic crystal surface light emitting device 120, the metasurface MS12 is formed directly on the substrate 101, so that it is possible to provide multi-point emission, beam diameter reduction, deflection, etc. without requiring additional components.

[0187] 13. Light-emitting device according to example 13 of an embodiment of the present technology FIG. 67 is a cross-sectional view of a light-emitting device 131 according to example 13 of an embodiment of the present technology.

[0188] As shown in FIG. 67, light emitting device 131 includes photonic crystal surface light emitting element 120 according to Example 12 and mounting substrate 500 on which photonic crystal surface light emitting element 120 is mounted.

[0189] In the light emitting device 131 , the photonic crystal surface light emitting element 120 is flip-chip mounted (junction-down mounted) on the mounting substrate 500 .

[0190] Here, the mounting substrate 500 is a drive substrate including a driver (drive circuit), but it may also be a wiring substrate.

[0191] In the light-emitting device 131, the photonic crystal surface light-emitting element 120 has an anode wiring 118. The anode wiring 118 is provided on the light-emitting mesa LM via the insulating film 110, with one end connected to the anode electrode 112 and the other end located on the periphery of the top of the light-emitting mesa LM.

[0192] The photonic crystal surface light emitting element 120 has the cathode electrode 111 electrically connected to the mounting substrate 500 (more specifically, the cathode side of the driver) via the first bump B1, and the other end of the anode wiring 118 electrically connected to the mounting substrate 500 (more specifically, the anode side of the driver) via the second bump B2.

[0193] According to the light emitting device 131, the photonic crystal surface light emitting element 120 is flip-chip mounted on the mounting substrate 500, so that high-speed driving is possible while saving power.

[0194] <14. Photonic crystal surface light-emitting device according to Example 14 of an embodiment of the present technology> Figure 68 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in Figure 63) of the metasurface MS14 of the photonic crystal surface light-emitting device according to Example 14 of an embodiment of the present technology.

[0195] The photonic crystal surface light emitting device of Example 14 has a configuration similar to that of the photonic crystal surface light emitting device 120 of Example 12, except that the metasurface is more specifically embodied, as shown in Figure 68.

[0196] In the metasurface MS14, the pillar group is part of the substrate 101 (e.g., a GaAs substrate). That is, each pillar P of the pillar group is formed by directly processing the back surface of the substrate 101.

[0197] The metasurface MS14 has, for example, a pitch PP of the pillars P of 200 to 400 nm, a height H of the pillars P of 400 to 1500 nm, and a diameter D of the pillars P of 100 to 300 nm.

[0198] Examples of the shape of the pillar P in a plan view include a circle, an ellipse, a triangle, a quadrangle such as a square or a rectangle, and other polygons.

[0199] The pillar P may have a tapered or inversely tapered vertical cross section.

[0200] In the photonic crystal surface light emitting device of Example 14, each pillar P is a part of the substrate 101, so there is no concern about the pillars P peeling off.

[0201] 15. Photonic crystal surface light emitting device according to Example 15 of an embodiment of the present technology> FIG. 69 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS15 of a photonic crystal surface light emitting device according to Example 15 of an embodiment of the present technology.

[0202] 69, the photonic crystal surface light emitting device according to Example 15 has the same configuration as the photonic crystal surface light emitting device according to Example 14, except that the metasurface MS15 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0203] According to the photonic crystal surface light emitting device of Example 15, the pillar group is buried by the buried layer EBL, so that the mechanical strength of the metasurface MS15 can be increased.

[0204] 16. Photonic crystal surface light-emitting device according to Example 16 of an embodiment of the present technology> FIG. 70 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS16 of a photonic crystal surface light-emitting device according to Example 16 of an embodiment of the present technology.

[0205] In the photonic crystal surface emitting device of Example 16, as shown in Figure 70, the metasurface MS16 has a configuration similar to that of the photonic crystal surface emitting device of Example 14, except that it has an anti-reflection coating AR that covers at least a portion (e.g., a part) of the surface of a pillar group including multiple pillars P.

[0206] In the metasurface MS16, an anti-reflection film AR covers the top of the pillar P. The material of the anti-reflection film AR is, for example, TiO ２ , SiN, SiO ２ , SiON, etc. The thickness of the antireflection film AR is preferably, for example, 10 nm to 200 nm.

[0207] According to the photonic crystal surface light emitting device of Example 16, the light transmittance at the interface between the top of each pillar P and air can be improved.

[0208] 17. Photonic crystal surface light emitting device according to Example 17 of an embodiment of the present technology> FIG. 71 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS17 of a photonic crystal surface light emitting device according to Example 17 of an embodiment of the present technology.

[0209] 71, the photonic crystal surface light emitting device according to Example 17 has the same configuration as the photonic crystal surface light emitting device according to Example 16, except that the metasurface MS17 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0210] According to the photonic crystal surface light emitting device of Example 17, the pillar group is buried by the buried layer EBL, so that the mechanical strength of the metasurface MS17 can be increased.

[0211] 18. Photonic crystal surface light-emitting device according to Example 18 of an embodiment of the present technology> FIG. 72 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of the metasurface MS18 of the photonic crystal surface light-emitting device according to Example 18 of an embodiment of the present technology.

[0212] In the photonic crystal surface emitting device of Example 18, as shown in Figure 72, the metasurface MS18 has a configuration similar to that of the photonic crystal surface emitting device of Example 16, except that it has antireflection films AR1 and AR2 that cover at least a portion (e.g., a part) of the surface of a pillar group including multiple pillars P.

[0213] In the metasurface MS18, an antireflection film AR1 covers the tops of the pillars P, and an antireflection film AR2 covers the area between adjacent pillars P (at least a part of the reference plane RP) on the back surface of the substrate 101. The materials for each antireflection film are, for example, TiO ２ , SiN, SiO ２, SiON, etc. The thickness of the antireflection film AR is preferably, for example, 10 nm to 200 nm.

[0214] The photonic crystal surface light emitting device of Example 18 can improve the light transmittance at the interface between the top of each pillar P and air and the transmittance at the interface between the reference plane RP and air.

[0215] 19. Photonic crystal surface light emitting device according to Example 19 of an embodiment of the present technology> FIG. 73 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS19 of a photonic crystal surface light emitting device according to Example 19 of an embodiment of the present technology.

[0216] 73, the photonic crystal surface light emitting device according to Example 19 has the same configuration as the photonic crystal surface light emitting device according to Example 18, except that the metasurface MS19 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0217] According to the photonic crystal surface light emitting device of Example 19, the pillar group is buried by the buried layer EBL, so that the mechanical strength of the metasurface MS19 can be increased.

[0218] <20. Photonic crystal surface light-emitting device according to Example 20 of an embodiment of the present technology> Figure 74 is a partial cross-sectional view (corresponding to the area surrounded by the dotted line in Figure 63) of the metasurface MS20 of the photonic crystal surface light-emitting device according to Example 20 of an embodiment of the present technology.

[0219] The photonic crystal surface emitting device of Example 20 has a configuration similar to that of the photonic crystal surface emitting device of Example 19, except that the metasurface MS20 has an anti-reflection film AR3 arranged on the buried layer EBL, as shown in Figure 74.

[0220] The anti-reflection film AR3 may be made of, for example, TiO ２ , SiN, SiO ２ , SiON, etc.

[0221] The antireflection film AR3 may be composed of a single layer or may have a laminated structure in which a plurality of layers are laminated. When the antireflection film AR3 has a laminated structure of three or more layers, a high refractive index layer (for example, TiO ２ layer) and a low refractive index layer (e.g., SiO ２ It is preferable that the thickness of each layer is about 10 nm to 500 nm.

[0222] According to the photonic crystal surface light emitting device of Example 20, the transmittance at the interface between the buried layer EBL and air can be improved, and the mechanical strength of the metasurface MS20 can be further increased.

[0223] <20.5. Photonic crystal surface light-emitting device according to Example 20.5 of one embodiment of the present technology> Figure 75 is a partial cross-sectional view (corresponding to the area surrounded by the dotted line in Figure 63) of the metasurface MS20.5 of the photonic crystal surface light-emitting device according to Example 20.5 of one embodiment of the present technology.

[0224] The photonic crystal surface emitting device of Example 20.5 has a configuration similar to that of the photonic crystal surface emitting device of Example 14, except that, as shown in Figure 75, an anti-reflection film AR is provided continuously along the surfaces of multiple pillars P and the reference plane RP.

[0225] In the photonic crystal surface light emitting device according to Example 20.5, the antireflection film AR can be formed by, for example, atomic layer deposition (ALD).

[0226] The anti-reflection film AR may be made of, for example, SiN or SiO ２ , SiON, etc. The thickness of the anti-reflection film AR is preferably, for example, about 0 to 200 nm.

[0227] According to the photonic crystal surface emitting device of Example 20.5, the antireflection film AR is continuously provided along the surfaces of the multiple pillars P and the reference plane RP, so that an antireflection effect can be imparted to all interfaces between the metasurface MS20.5 and air.

[0228] 21. Photonic crystal surface light-emitting device according to Example 21 of an embodiment of the present technology> FIG. 76 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS21 of a photonic crystal surface light-emitting device according to Example 21 of an embodiment of the present technology.

[0229] In the photonic crystal surface light-emitting device of Example 21, as shown in Figure 76, the pillar group including multiple pillars P has a configuration similar to that of the photonic crystal surface light-emitting device of Example 14, except that it is a separate member from the substrate 101.

[0230] Here, the material of the pillar P is, for example, a-Si (amorphous silicon), c-Si (crystalline silicon), TiO ２ The pitch of the pillars P is preferably, for example, about 200 to 400 nm. The height of the pillars P is preferably, for example, about 400 to 1500 nm. The diameter of the pillars P is preferably, for example, about 100 to 300 nm.

[0231] In the photonic crystal surface light emitting device of Example 21, the pillar group is a separate member from the substrate 101, so that the pillars P can be formed with higher precision.

[0232] 22. Photonic crystal surface light-emitting device according to Example 22 of an embodiment of the present technology> FIG. 77 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of the metasurface MS22 of the photonic crystal surface light-emitting device according to Example 22 of an embodiment of the present technology.

[0233] 77, the photonic crystal surface light emitting device according to Example 22 has the same configuration as the photonic crystal surface light emitting device according to Example 21, except that the metasurface MS22 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２, SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0234] According to the photonic crystal surface light-emitting device of Example 22, the pillar group is buried by the buried layer EBL, thereby increasing the mechanical strength of the metasurface MS22 and suppressing peeling of the pillar P from the substrate 101.

[0235] 23. Photonic crystal surface light-emitting device according to Example 23 of an embodiment of the present technology> FIG. 78 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of the metasurface MS23 of the photonic crystal surface light-emitting device according to Example 23 of an embodiment of the present technology.

[0236] In the photonic crystal surface emitting device of Example 23, as shown in Figure 78, the metasurface MS23 has a configuration similar to that of the photonic crystal surface emitting device of Example 21, except that it has an anti-reflection coating AR that covers at least a portion (e.g., a part) of the surface of a pillar group including multiple pillars P.

[0237] In the metasurface MS23, an anti-reflection film AR covers the top of the pillar P. The material of the anti-reflection film AR is, for example, TiO ２ , SiN, SiO ２ , SiON, etc. The thickness of the anti-reflection film AR is preferably, for example, about 10 nm to 200 nm.

[0238] According to the photonic crystal surface light emitting device of Example 23, the light transmittance at the interface between the top of each pillar P and air can be improved.

[0239] 24. Photonic crystal surface light-emitting device according to Example 24 of an embodiment of the present technology> FIG. 79 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS24 of a photonic crystal surface light-emitting device according to Example 24 of an embodiment of the present technology.

[0240] 79, the photonic crystal surface light emitting device according to Example 24 has the same configuration as the photonic crystal surface light emitting device according to Example 23, except that the metasurface MS24 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0241] According to the photonic crystal surface light-emitting device of Example 24, the pillar group is buried by the buried layer EBL, thereby increasing the mechanical strength of the metasurface MS24 and suppressing peeling of the pillar P from the substrate 101.

[0242] 25. Photonic crystal surface light-emitting device according to Example 25 of an embodiment of the present technology> FIG. 80 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of the metasurface MS25 of the photonic crystal surface light-emitting device according to Example 25 of an embodiment of the present technology.

[0243] In the photonic crystal surface emitting device of Example 25, as shown in Figure 80, the metasurface MS25 has a configuration similar to that of the photonic crystal surface emitting device of Example 23, except that it has an anti-reflection film AR4 arranged between a pillar group including multiple pillars P and the substrate 101.

[0244] The anti-reflection film AR4 may be made of, for example, TiO ２ , SiN, SiO ２ , SiON, etc. The thickness of the anti-reflection film AR is preferably, for example, about 10 nm to 400 nm.

[0245] The photonic crystal surface light emitting device of Example 25 can improve the transmittance at the interface between the top of each pillar and air and the transmittance at the interface between the reference plane RP and air.

[0246] 26. Photonic Crystal Surface Light Emitting Device According to Example 26 of an Embodiment of the Present Technology> FIG. 81 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS26 of a photonic crystal surface light emitting device according to Example 26 of an embodiment of the present technology.

[0247] 81, the photonic crystal surface light emitting device according to Example 26 has the same configuration as the photonic crystal surface light emitting device according to Example 25, except that the metasurface MS26 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0248] According to the photonic crystal surface light-emitting device of Example 26, the pillar group is buried by the buried layer EBL, thereby increasing the mechanical strength of the metasurface MS26 and suppressing peeling of the pillar P from the antireflection film AR4.

[0249] 27. Photonic crystal surface light-emitting device according to Example 27 of an embodiment of the present technology> FIG. 82 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS27 of a photonic crystal surface light-emitting device according to Example 27 of an embodiment of the present technology.

[0250] In the photonic crystal surface emitting device of Example 27, as shown in Figure 82, the antireflection film arranged between the pillar group including multiple pillars P and the substrate 101 has the same configuration as the photonic crystal surface emitting device of Example 25, except that the thickness T1 of the portion AR4-1 where the pillars P are not arranged is different from the thickness T2 of the portion AR4-2 where the pillars P are arranged.

[0251] T1 is preferably, for example, about 10 nm to 400 nm, and T2 is preferably, for example, about 10 nm to 350 nm.

[0252] Here, T1>T2 is set, but T1<T2 may also be set.

[0253] According to the photonic crystal surface light emitting device of Example 27, the thickness T1 of the portion AR4-1 where the pillar P is not arranged and the thickness T2 of the portion AR4-2 where the pillar P is arranged can each be optimized (preferably).

[0254] 28. Photonic crystal surface light-emitting device according to Example 28 of an embodiment of the present technology> FIG. 83 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS28 of a photonic crystal surface light-emitting device according to Example 28 of an embodiment of the present technology.

[0255] 83, the photonic crystal surface light emitting device according to Example 28 has the same configuration as the photonic crystal surface light emitting device according to Example 27, except that the metasurface MS28 has a buried layer EBL that buries a pillar group including a plurality of pillars P. Examples of materials for the buried layer EBL include TiO ２ , SiN, SiO ２ , SiON, organic materials, etc. The thickness of the buried layer EBL is preferably the height of the pillar P plus α (0 to 3000 nm). The buried layer EBL is also called a "protective layer."

[0256] According to the photonic crystal surface light-emitting device of Example 28, the pillar group is buried by the buried layer EBL, thereby increasing the mechanical strength of the metasurface MS28 and suppressing peeling of the pillar P from the antireflection film including the portions AR4-1 and AR4-2.

[0257] 29. Photonic crystal surface light-emitting device according to Example 29 of an embodiment of the present technology> FIG. 84 is a partial cross-sectional view (corresponding to the area surrounded by the dashed line in FIG. 63 ) of a metasurface MS29 of a photonic crystal surface light-emitting device according to Example 29 of an embodiment of the present technology.

[0258] The photonic crystal surface emitting device of Example 29 has a configuration similar to that of the photonic crystal surface emitting device of Example 28, except that the metasurface MS29 has an antireflection film AR3 arranged on the buried layer EBL, as shown in Figure 84.

[0259] The anti-reflection film AR3 may be made of, for example, TiO ２ , SiN, SiO ２ , SiON, etc.

[0260] The antireflection film AR3 may be composed of a single layer or may have a laminated structure in which a plurality of layers are laminated. When the antireflection film AR3 has a laminated structure of three or more layers, a high refractive index layer (for example, TiO ２ layer) and a low refractive index layer (e.g., SiO ２ ) are preferably laminated alternately. The thickness of each layer is preferably about 10 nm to 500 nm.

[0261] According to the photonic crystal surface light emitting device of Example 29, the transmittance at the interface between the buried layer EBL and air can be improved, and the mechanical strength of the metasurface MS29 can be further increased.

[0262] 85A is a schematic cross-sectional view showing an emission state of photonic crystal surface light emitting device 300 according to Example 30 of an embodiment of the present technology. Fig. 85B is a diagram showing an emission light pattern (far-field pattern) of the photonic crystal surface light emitting device according to Example 30 of an embodiment of the present technology. Fig. 86 is a diagram for explaining the planar configuration of metasurface MS30 (substantially the same as metasurface MS12) of the photonic crystal surface light emitting device according to Example 30 of an embodiment of the present technology.

[0263] In the photonic crystal surface light-emitting device 300 of Example 30, the light from the light-emitting element section LE is divided into a number of radial lights by the metasurface MS30 (see Figure 85A), and a dot pattern dotP (multi-point dot pattern, far-field pattern) including a number of dots SL1-dot can be generated (see Figure 85B).

[0264] In order to generate such a multi-point dot pattern, it is preferable that the pillar group includes a first pillar P1 and at least one second pillar P2 whose center is located within a distance range of 5 times the radius R of the first pillar P1 from the center of the first pillar P1 and whose diameter differs from that of the first pillar P1 by 50 nm or more, as in the metasurface MS30 shown in Figure 86.

[0265] Here, the pitch of each pillar is preferably, for example, about 200 to 400 nm. The height of each pillar is preferably, for example, about 400 to 1500 nm. The diameter of each pillar is preferably, for example, about 100 to 300 nm. The material of each pillar is, for example, a-Sic-Si, TiO ２ The shape of each pillar in plan view may be a circle, an oval, a rectangle, or another polygon.

[0266] 31. Photonic Crystal Plane Light Emitting Device According to Example 30 of an Embodiment of the Present Technology FIG. 87 is a schematic cross-sectional view showing a light emitting state of a photonic crystal plane light emitting device 310 according to Example 31 of an embodiment of the present technology.

[0267] In the photonic crystal surface light-emitting device of Example 31, as shown in Figure 87, the metasurface MS31 is designed so that a phase difference of 1 / 2 of the emission wavelength occurs between a first region A1 corresponding to an area of ​​less than X% including the center of the light-emitting region of the light-emitting element section LE and a second region A2 corresponding to an area of ​​more than X% on the outer periphery of the first region A1 of the light-emitting region of the light-emitting element section LE. This allows interference to occur between the first region A1 and the second region A2 in the metasurface MS31, thereby reducing the beam diameter. The above X% is preferably 30 to 50%, and more preferably 40%.

[0268] Here, the pitch of the pillars P is preferably, for example, about 200 to 400 nm. The height of the pillars P is preferably, for example, about 400 to 1500 nm. The diameter of the pillars P is preferably, for example, about 100 to 300 nm (however, any fixed value). The material of the pillars P is, for example, a-Si, c-Si, TiO ２ The shape of the pillar P in plan view may be a circle, an oval, a rectangle, or another polygon.

[0269] 32. Photonic Crystal Surface Emitting Device According to Example 32 of an Embodiment of the Present Technology> Fig. 88A is a diagram showing an emitted light pattern (far-field pattern) of a photonic crystal surface emitting device according to Example 32 of an embodiment of the present technology. Fig. 88B is a schematic cross-sectional view showing an emission state of a photonic crystal surface emitting device according to Example 32 of an embodiment of the present technology. Fig. 95A is a plan view of a metasurface of a photonic crystal surface emitting device according to Example 32 of an embodiment of the present technology, showing a pillar pitch. Fig. 95B is a plan view of pillars of a metasurface of a photonic crystal surface emitting device according to Example 32 of an embodiment of the present technology, showing an aspect ratio of the pillars. Fig. 96 is a plan view of a metasurface of a photonic crystal surface emitting device according to Example 32 of an embodiment of the present technology, showing an azimuth angle of the pillars.

[0270] In the photonic crystal surface light-emitting device of Example 32, as shown in Figures 88A and 88B, the light-emitting element section LE emits flood light (fundamental mode light BML) toward the metasurface MS32, and the metasurface MS32 is designed to reduce the illuminance unevenness of the emitted flood light FL.

[0271] Specifically, as shown in Figure 95A, the metasurface MS32 has multiple pillars P with anisotropic shapes in a plan view, and generates, for example, flood light. By appropriately arranging (for example, arranging in random orientations at a predetermined pitch PP) multiple pillars P (e.g., rectangular pillars) each with anisotropic shapes in a plan view, it is possible to generate flood light FL with reduced illuminance unevenness. The planar shapes of the pillars P are, for example, rectangles, ellipses, or other shapes with different aspect ratios.

[0272] The aspect ratio of the pillar P in length to width is preferably 1<b / a≦10 (see FIG. 95B).

[0273] As shown in Figure 96, by arranging each pillar P (each rectangular pillar) so that the azimuth angle θ is random, it is possible to make the polarization azimuth angles of adjacent emitted light beams different, thereby reducing the coherence of flood light and achieving a more uniform illuminance distribution.

[0274] Here, the pitch PP of the pillars P is preferably, for example, about 200 to 400 nm. The height of the pillars P is preferably, for example, about 400 to 1500 nm. The diameter of the pillars P is preferably, for example, about 100 to 300 nm (however, any fixed value). The material of the pillars P is, for example, a-Si, c-Si, TiO ２ The shape of the pillar P in plan view may be a circle, an oval, a rectangle, or another polygon.

[0275] <33. Photonic crystal surface light emitting device according to Example 33 of an embodiment of the present technology>

[0276] FIG. 89 is a cross-sectional view showing the light emitting state of a photonic crystal surface light emitting device according to Example 33 of an embodiment of the present technology.

[0277] The photonic crystal surface light-emitting device of Example 33 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 12, except that it is provided with a light-shielding portion 121 that blocks the higher-order mode light HML from the light-emitting device portion LE, as shown in Figure 89.

[0278] Here, the light-shielding portion 121 is arranged in a circular pattern in a planar view on the metasurface MS12 so as to block only the optical path of the higher-order mode light HML. The light-shielding portion 121 preferably has light-absorbing and / or light-reflective properties. The light-shielding portion 121 may contain a metal such as W or Cr. The light-shielding portion 121 may have a single-layer structure or a multilayer structure.

[0279] According to the photonic crystal surface light emitting device of Example 33, the higher-order mode light HML can be blocked, so that the fundamental mode light BML and the higher-order mode light HML can be separated more reliably.

[0280] <34. Photonic crystal surface light emitting device according to Example 34 of an embodiment of the present technology>

[0281] FIG. 90 is a cross-sectional view showing the light emitting state of a photonic crystal surface light emitting device according to Example 34 of an embodiment of the present technology.

[0282] The photonic crystal surface light-emitting device of Example 34 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 12, except that it is provided with a light-shielding portion 121 that blocks the second split light SL2 produced by splitting the higher-order mode light HML from the light-emitting device portion LE by the metasurface MS12, as shown in Figure 90.

[0283] Here, the light-shielding portion 121 is arranged in a circular pattern in a plan view on the metasurface MS12 so as to block only the optical path of the second divided light SL2. The light-shielding portion 121 preferably has light-absorbing and / or light-reflective properties. The light-shielding portion 121 may contain a metal such as W or Cr. The light-shielding portion 121 may have a single-layer structure or a multilayer structure.

[0284] According to the photonic crystal surface light emitting device of Example 34, the second divided light SL2 obtained by dividing the higher-order mode light HML can be blocked, so that the first divided light SL1 and the second divided light SL2 obtained by dividing the fundamental mode light BML can be more reliably separated.

[0285] <35. Modifications of the present technology>

[0286] The present technology is not limited to the examples of the above-described embodiment, and various modifications are possible.

[0287] (Variation 1) For example, as in photonic crystal surface light emitting device 10-M1 according to Variation 1 of Example 1 shown in Fig. 58, a plurality of light emitting element portions LE may have a mesare-less structure. In photonic crystal surface light emitting device 10-M1, as one example, ion implantation regions IIA (insulating regions) are provided between the light emitting element portions LE. As one example, ion implantation regions IIA are provided across first cladding layer 103, active layer 104, photonic crystal layer 106, second cladding layer 107, reflecting mirror 108, and second contact layer 109.

[0288] (Variant 2) For example, as shown in Figures 59A, 59B and 60 (schematic oblique view), a photonic crystal surface light emitting device 10-M2 according to variant 2 of Example 1 has a metaoptics layer 201 in which multiple (e.g., four) optical element sections (e.g., first to fourth optical element sections 201A to 201D), each of which is a metaoptics (e.g., a metasurface), are arranged two-dimensionally (e.g., in a matrix arrangement).

[0289] The first and second optical element units 201A and 201B are arranged side by side along a predetermined direction, which is the alignment direction of the first and second light-emitting element units LE1 and LE2, to form a first optical element unit pair, and the third and fourth optical element units 201C and 201D are arranged side by side along the predetermined direction, which is the alignment direction of the third and fourth light-emitting element units LE3 and LE4, to form a second optical element unit pair.

[0290] The metaoptics as each optical element portion has a group of cylindrical pillars (see Figure 60) arranged along the first direction, each of which is made up of a plurality of cylindrical pillars with a diameter of several hundred nanometers, the diameter of which gradually increases or decreases from the cylindrical pillar at one end to the cylindrical pillar at the other end in the first direction.

[0291] The meta-optics layer 201 has a protective film for protecting the cylindrical pillars, and an anti-reflection film 202 is provided on the protective film.

[0292] Each metaoptic in the metaoptics layer 201 is designed to tilt the principal ray direction of light from the corresponding light-emitting element portion LE with respect to the substrate normal direction (see FIGS. 59A and 59B).

[0293] 61, a photonic crystal surface light emitting device 10-M3 according to a third modification of the first embodiment may have a single light emitting element portion LE and a prism as a single optical element portion 200 corresponding to the light emitting element portion LE. Note that instead of the prism as the single optical element portion 200, a metaoptics layer having a single metaoptics may be provided.

[0294] (Variant 4) For example, as shown in Figure 91, as in the metasurface MS-M4 of a photonic crystal surface light-emitting device according to variant 4 of one embodiment, an anti-reflection film (e.g., anti-reflection film AR2) may be provided only on the portion of the reference plane RP where pillars P are not provided.

[0295] (Variant 5) For example, as shown in Figure 92, in the case of a metasurface MS-M5 of a photonic crystal surface light-emitting device according to variant 5 of one embodiment, when the pillar P is separate from the substrate 101, an anti-reflection film AR2 may be provided on the portion of the reference plane RP where the pillar P is not provided.

[0296] (Variant 6) For example, as shown in Figure 93, in the case of a metasurface MS-M6 of a photonic crystal surface light-emitting device according to variant 6 of one embodiment, when the pillars P are separate from the substrate 101, an anti-reflection film (e.g., anti-reflection film AR4) may be provided only between the substrate 101 and the multiple pillars P.

[0297] For example, the irradiation pattern constituted by at least one emitted light pattern may be a combination of at least two types of emitted light patterns selected from a spot pattern, a dot pattern, a stripe pattern, a line pattern, and an area pattern.

[0298] For example, the plurality of light-emitting element units LE may emit light in different light-emitting patterns.

[0299] For example, the irradiation pattern may be one in which a plurality of emitted light patterns are arranged in a matrix other than 2×2.

[0300] For example, in each of the above-mentioned embodiments and variant examples, a photonic crystal surface-emitting laser has been used as an example of a photonic crystal surface-emitting element of a light-emitting device according to the present technology, but the present technology can also be applied to, for example, a photonic crystal light-emitting diode (resonant or non-resonant type).

[0301] For example, in each of the above-described embodiments and modified examples, a semiconductor multilayer film reflector is used as the reflector, but this is not limited thereto. For example, a dielectric multilayer film reflector or a hybrid mirror including at least two of a semiconductor multilayer film reflector, a dielectric multilayer film reflector, and a metal reflector may also be used.

[0302] For example, in each of the above-described embodiments and modified examples, the photonic crystal surface light-emitting element is made of a material that is lattice-matched to GaAs (GaAs-based compound semiconductor), but this is not limited thereto, and for example, a material that is lattice-matched to InP (InP-based compound semiconductor) or a material that is lattice-matched to GaN (GaN-based compound semiconductor) may also be used.

[0303] For example, the conductivity types of the layers on both sides of the active layer 104 of the photonic crystal surface light emitting device according to each of the above-described embodiments and modifications may be reversed. In this case, reference numeral 112 is the anode electrode, reference numeral 113 is the anode wiring, and reference numeral 111 is the cathode electrode.

[0304] At least one of the first and second contact layers 102 and 109 may not be provided.

[0305] One of the first and second cladding layers 103 and 107 may not be provided. In this case, the semiconductor multilayer film reflecting mirror serving as the reflecting mirror 108 may also serve as the one of the cladding layers.

[0306] The reflecting mirror 108 may not be provided.

[0307] The dummy element portion DE does not necessarily have to be provided.

[0308] For example, in each of the above embodiments and modifications, a MOSFET is used as the switching element of the laser driver, but other field effect transistors such as a junction FET may also be used, or a bipolar transistor may also be used.

[0309] For example, the photonic crystal surface light emitting device according to the present technology may have a multi-junction structure in which two or more active layers 104 are stacked. In this case, it is preferable that a tunnel junction layer is disposed between the active layers 104 adjacent to each other in the stacking direction.

[0310] Parts of the configurations of the photonic crystal surface light emitting device of each of the above-described embodiments and modifications may be combined within a range that does not contradict each other.

[0311] In each of the above embodiments and modifications, the material, conductivity type, thickness, width, value, shape, size, etc. of each layer constituting the photonic crystal surface light emitting device and the mounting substrate can be changed as appropriate within the range in which the device functions as a photonic crystal surface light emitting device.

[0312] 13. Application Examples to Electronic Devices The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, a robot, or a low-power device (for example, a smartphone, a smartwatch, a tablet, a mouse, a laptop computer, or the like), or as a communication device.

[0313] The light emitting device according to the present technology can also be applied as a light source for devices that form or display images using laser light (for example, laser printers, laser copiers, projectors, head-mounted displays, head-up displays, etc.).

[0314] 14. Example of Application of Photonic Crystal Surface Light Emitting Device to Distance Measuring Device An example of application of the photonic crystal surface light emitting device 10 according to the first embodiment will be described below.

[0315] 97 shows an example of a schematic configuration of a distance measurement device 1000 (distance measuring device) including a photonic crystal surface light emitting device 10, as an example of an electronic device according to the present technology. The distance measurement device 1000 measures the distance to a subject S by a TOF (Time Of Flight) method. The distance measurement device 1000 includes the photonic crystal surface light emitting device 10. The distance measurement device 1000 includes, for example, the photonic crystal surface light emitting device 10, a light receiving device 125, a lens 130, a signal processing unit 145, a control unit 155, a display unit 165, and a storage unit 170.

[0316] The light receiving device 125 receives light emitted from the photonic crystal surface light emitting device 10 and reflected by the subject S (object). That is, the light receiving device 125 detects the light reflected by the subject S. The lens 130 is a lens, such as a condenser lens, that collects the light reflected by the subject S and guides it to the light receiving device 125.

[0317] The signal processing unit 145 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 125 and the reference signal input from the control unit 155. The control unit 155 is configured to include, for example, a time-to-digital converter (TDC). The reference signal may be a signal input from the control unit 155, or may be an output signal from a detection unit that directly detects the output of the photonic crystal surface light emitting device 10. The control unit 155 is, for example, a processor that controls the photonic crystal surface light emitting device 10, the light receiving device 125, the signal processing unit 145, the display unit 165, and the storage unit 170. The control unit 155 is a circuit that measures the distance to the subject S based on the signal generated by the signal processing unit 145. The control unit 155 generates a video signal for displaying information about the distance to the subject S and outputs it to the display unit 165. The display unit 165 displays the information about the distance to the subject S based on the video signal input from the control unit 155. The control unit 155 stores the information about the distance to the subject S in the storage unit 170.

[0318] In this application example, instead of the photonic crystal surface light emitting device 10, any of the photonic crystal surface light emitting devices 20, 30, 40, 50, 60, 70, 80, 90, 100, 119, 120, 10-M1, 10-M2, 10-M3, light emitting device 1, and 131 can also be applied to the distance measurement device 1000.

[0319] 15. Example of Mounting Distance Measuring Device on a Moving Body FIG. 98 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0320] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 98, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0321] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0322] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0323] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the above-described distance measurement device 1000. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc. based on the acquired distance data.

[0324] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0325] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0326] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0327] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0328] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying information to vehicle occupants or the outside of the vehicle. In the example of Fig. 98, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0329] FIG. 99 is a diagram showing an example of the installation position of the distance measurement device 12031.

[0330] In FIG. 99, a vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as a distance measurement device 12031.

[0331] Distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of vehicle 12100. Distance measuring device 12101 provided on the front nose and distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire data ahead of vehicle 12100. Distance measuring devices 12102 and 12103 provided on the side mirrors mainly acquire data on the sides of vehicle 12100. Distance measuring device 12104 provided on the rear bumper or back door mainly acquires data behind vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0332] 99 shows an example of the detection ranges of the distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of the distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of the distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of the distance measuring device 12104 provided on the rear bumper or back door.

[0333] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0334] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0335] The above describes an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the distance measurement device 12031 of the above-described configuration.

[0336] The present technology can also be configured as follows. (1) A photonic crystal surface light-emitting device comprising at least one element including: a light-emitting device section including an active layer and a photonic crystal layer stacked on each other; and an optical element section provided on the emission side of the light-emitting device section. (2) The photonic crystal surface light-emitting device according to (1), in which the optical element section controls the chief ray direction of the emitted light. (3) The photonic crystal surface light-emitting device according to (2), in which the optical element section tilts the chief ray direction with respect to the stacking direction of the active layer and the photonic crystal layer. (4) The photonic crystal surface light-emitting device according to (2) or (3), in which the optical element section controls the chief ray direction so that an output light pattern, which is a pattern of the output light, is asymmetric with respect to a point of the output light pattern corresponding to the center of the photonic crystal in the photonic crystal layer. (5) The photonic crystal surface light-emitting device according to any one of (1) to (4), in which the optical element section is a prism. (6) The photonic crystal surface emitter according to any one of (1) to (5), wherein the emission surface of the optical element section is inclined with respect to the stacking direction of the active layer and the photonic crystal layer. (7) The photonic crystal surface emitter according to any one of (1) to (4), wherein the optical element section is metaoptics. (8) The photonic crystal surface emitter according to any one of (1) to (7), comprising a plurality of the elements arranged along a plane perpendicular to the stacking direction of the active layer and the photonic crystal layer. (9) The photonic crystal surface emitter according to (8), wherein the light emitting element sections of the plurality of elements emit light with the same emission pattern, and each of the optical element sections of the plurality of elements tilts the chief ray direction of light from the corresponding light emitting element section with respect to the stacking direction. (10) The photonic crystal surface emitter according to (8) or (9), wherein each of the optical element sections of the plurality of elements controls the chief ray directions of light from the corresponding light emitting element section to be non-parallel to each other. (11) The photonic crystal surface light-emitting device according to any one of (8) to (10), wherein the emission surfaces of the optical element portions of at least two of the plurality of elements are inclined with respect to the stacking direction, and the inclination directions of the emission surfaces of the optical element portions of the at least two elements are different.(12) The photonic crystal surface light emitting device according to any one of (8) to (11), wherein the emission light patterns of the plurality of elements are arranged two-dimensionally to form an irradiation pattern. (13) The photonic crystal surface light emitting device according to (12), wherein at least one of the emission light patterns of the plurality of elements is a pattern in which spot-like or dot-like light is arranged two-dimensionally. (14) The photonic crystal surface light emitting device according to (13), wherein adjacent light beams partially overlap. (15) The photonic crystal surface light emitting device according to any one of (8) to (14), wherein the emission light patterns of the plurality of elements are arranged one-dimensionally to form an irradiation pattern. (16) The photonic crystal surface light emitting device according to (15), wherein each of the emission light patterns of the plurality of elements is a band-like pattern whose longitudinal direction is a direction orthogonal to the arrangement direction of the emission light patterns of the plurality of elements. (17) The photonic crystal surface light emitting device according to any one of (1) to (16), wherein the shape of the optical element portion in a planar view is polygonal. (18) The photonic crystal surface emitter according to any one of (1) to (16), wherein the planar shape of the optical element portion is circular or elliptical. (19) The photonic crystal surface emitter according to any one of (1) to (18), wherein the element includes a rim portion provided around the optical element portion. (20) The photonic crystal surface emitter according to claim 18, wherein a gap is present between the optical element portion and the rim portion. (21) The photonic crystal surface emitter according to any one of (1) to (20), wherein the light emitting element portion emits a plurality of beams of light toward the optical element portion. (22) The photonic crystal surface emitter according to (1), wherein the optical element portion splits the light from the light emitting element portion into a plurality of beams of light. (23) The photonic crystal surface emitter according to (22), wherein the chief ray direction of at least one beam of light among the plurality of beams of light is inclined with respect to the stacking direction of the active layer and the photonic crystal layer. (24) The photonic crystal surface light emitting device according to (22) or (23), wherein the plurality of light beams are radially emitted from the optical element portion. (25) The photonic crystal surface light emitting device according to any one of (22) to (24), wherein the light emitting element portion emits the light beams in a stacking direction of the active layer and the photonic crystal layer.(26) The photonic crystal surface emitter according to any one of (22) to (25), wherein the light from the light-emitting element section includes fundamental mode light and higher-order mode light surrounding the fundamental mode light, the fundamental mode light is split into a plurality of first split light beams by the optical element section, and the higher-order mode light is emitted from the optical element section as second split light beams spatially separated from the plurality of first split light beams. (27) The photonic crystal surface emitter according to (26), wherein a light-shielding section is provided to block the second split light beams. (28) The photonic crystal surface emitter according to any one of (22) to (27), wherein the light from the light-emitting element section includes fundamental mode light and higher-order mode light surrounding the fundamental mode light, and a light-shielding section is provided to block the higher-order mode light. (29) The photonic crystal surface emitter according to any one of (22) to (28), wherein the optical element section includes a metasurface. (30) The photonic crystal surface emitter according to (29), wherein the metasurface has a pillar group including a plurality of pillars arranged two-dimensionally on a reference plane. (31) The photonic crystal surface emitter according to (29) or (30), wherein a far-field pattern of light emitted from the optical element section is a multi-point dot pattern. (32) The photonic crystal surface emitter according to (30) or (31), wherein the pillar group includes: a first pillar; and at least one second pillar whose center is located within a distance range from the center of the first pillar by no more than five times the radius of the first pillar and whose diameter differs from that of the first pillar by 50 nm or more. (33) The photonic crystal surface emitter according to any one of (30) to (32), wherein the light-emitting element section is provided on one surface of a substrate, and the optical element section is provided on the other surface of the substrate. (34) The photonic crystal surface emitter according to (33), wherein the pillar group is a part of the substrate. (35) The photonic crystal surface emitter according to (33), wherein the pillar group is a separate member from the substrate. (36) The photonic crystal surface emitter according to (35), wherein the optical element section has an antireflection film disposed between the pillar group and the substrate. (37) The photonic crystal surface emitter according to (36), wherein the antireflection film has a thickness different between a portion where the pillars are disposed and a portion where the pillars are not disposed.(38) The photonic crystal surface emitter according to any one of (30) to (37), wherein the optical element section has an antireflection film covering the pillars and / or the reference plane. (39) The photonic crystal surface emitter according to (38), wherein the antireflection film is provided along the pillars and the reference plane. (40) The photonic crystal surface emitter according to (38) or (39), wherein the antireflection film covers the tops of the pillars. (41) The photonic crystal surface emitter according to any one of (38) to (40), wherein the antireflection film covers portions of the reference plane where no pillars are provided. (42) The photonic crystal surface emitter according to any one of (30) to (41), wherein the optical element section has a burying layer that buryes the group of pillars. (43) The photonic crystal surface emitter according to (42), wherein the optical element section has an antireflection layer disposed on the burying layer. (44) The photonic crystal surface emitter according to any one of (29) to (43), wherein the metasurface is designed so that a phase difference of ½ of the emission wavelength occurs between a first region corresponding to 40% or less of an area including the center of the light-emitting region of the light-emitting element section and a second region corresponding to 40% or more of an area of ​​the light-emitting region on the outer periphery of the first region. (45) The photonic crystal surface emitter according to any one of (29) to (44), wherein the light-emitting element section emits light toward the optical element section, and the metasurface is designed to reduce unevenness in illuminance of the light. (46) The photonic crystal surface emitter according to any one of (29) to (45), wherein the light-emitting element section emits light toward the optical element section, and the metasurface has a plurality of pillars each having an anisotropic shape in a planar view and arranged to reduce unevenness in illuminance of the light. (47) A light emitting device comprising: a photonic crystal surface light emitting element including at least one element having: a light emitting element section including an active layer and a photonic crystal layer stacked on each other; and an optical element section provided on the emission side of the light emitting element section; and a mounting substrate on which the photonic crystal surface light emitting element is mounted.(48) A light-emitting device comprising: a photonic crystal surface light-emitting element including at least one element having: a light-emitting element section including an active layer and a photonic crystal layer stacked on each other, and an optical element section provided on the emission side of the light-emitting element section; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted. (49) An electronic device comprising: a photonic crystal surface light-emitting element including at least one element having: a light-emitting element section including an active layer and a photonic crystal layer stacked on each other, and an optical element section provided on the emission side of the light-emitting element section. (50) An electronic device comprising: a light-emitting device comprising: a photonic crystal surface light-emitting element including at least one element having: a light-emitting element section including an active layer and a photonic crystal layer stacked on each other, and an optical element section provided on the emission side of the light-emitting element section; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted.

[0337] 1, 131: Light-emitting device 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 119, 120, 10-M1, 10-M2, 10-M3: Photonic crystal surface light-emitting device 101: Substrate 104: Active layer 106: Photonic crystal layer MS12, MS14, MS15, MS16, MS17, MS18, MS19, MS20, MS20.5, MS21, MS22, MS23, MS24, MS25, MS26, MS27, MS28, MS29, MS30, MS31, MS32, MS-M4, MS-M5, MS-M6 106a: Modified refractive index periodic structure (photonic crystal) C: Center of photonic crystal 200, 200A, 200B, 200C, 200D, 200E, 200F, 200G, 201A, 201B, 201C, 201D: Optical element section E, E1, E2, E3, E4: Elements ES, ES-A, ES-B, ES-C, ES-D: Emission surface LE, LE1, LE2, LE3, L4: Light-emitting element section PR, PR1, PR2, PR3, PR4: Chief ray direction ELP, ELP-A, ELP-B, ELP-C, ELP-D: Emitted light pattern ELP1, ELP2, ELP3, ELP4: Irradiation pattern RM: Rim section G: Gap P: Pillar PG: Pillar group SL1: First divided light SL2: Second divided light BML: Fundamental mode light HML: Higher order mode light EBL: Buried layer AR, AR1, AR2, AR3, AR4, AR4-1, AR4-2: Anti-reflection coating RP: Reference plane

Claims

1. A photonic crystal surface light-emitting device comprising at least one element including: a light-emitting element section including an active layer and a photonic crystal layer stacked on top of each other; and an optical element section provided on the emission side of the light-emitting element section.

2. The photonic crystal surface light emitting device according to claim 1, wherein the optical element portion controls the direction of the chief ray of the emitted light.

3. The photonic crystal surface light emitting device according to claim 2, wherein the optical element portion tilts the direction of the principal light with respect to the stacking direction of the active layer and the photonic crystal layer.

4. The photonic crystal surface light emitting device according to claim 2, wherein the optical element section controls the direction of the chief ray so that the emitted light pattern is asymmetric with respect to a point of the emitted light pattern corresponding to the center of the photonic crystal of the photonic crystal layer.

5. The photonic crystal surface light emitting device according to claim 1, wherein the optical element portion is a prism.

6. The photonic crystal surface light emitting device according to claim 5, wherein the light emitting surface of the optical element portion is inclined with respect to the lamination direction of the active layer and the photonic crystal layer.

7. The photonic crystal surface light emitting device according to claim 1, wherein the optical element portion is a metaoptic.

8. The photonic crystal surface light emitting device according to claim 1, comprising a plurality of said elements arranged along a plane perpendicular to the stacking direction of said active layer and said photonic crystal layer.

9. A photonic crystal surface light-emitting device according to claim 8, wherein the light-emitting element portions of the plurality of elements emit light in the same light-emitting pattern, and at least one of the optical element portions of the plurality of elements tilts the chief ray direction of light from the corresponding light-emitting element portion with respect to the stacking direction.

10. The photonic crystal surface light emitting device according to claim 8, wherein each of the optical element portions of the plurality of elements controls the direction of the chief rays of light from the corresponding light emitting element portion to be non-parallel to each other.

11. A photonic crystal surface light-emitting device according to claim 8, wherein the emission surfaces of the optical element portions of at least two of the plurality of elements are inclined with respect to the stacking direction, and the inclination directions of the emission surfaces of the optical element portions of the at least two elements are different.

12. The photonic crystal surface light emitting device according to claim 8, wherein the emission light patterns of the plurality of elements are arranged two-dimensionally to form an irradiation pattern.

13. The photonic crystal surface light emitting device according to claim 12, wherein at least one of the light emission patterns of the plurality of elements is a pattern in which spot-like or dot-like light is arranged two-dimensionally.

14. The photonic crystal surface light emitting device according to claim 13, wherein adjacent light beams partially overlap each other.

15. The photonic crystal surface light emitting device according to claim 8, wherein the emitted light patterns of the plurality of elements are arranged one-dimensionally to form an irradiation pattern.

16. The photonic crystal surface light emitting device according to claim 15, wherein at least one of the emission light patterns of the plurality of elements is a band-shaped pattern having a longitudinal direction perpendicular to the arrangement direction of the emission light patterns of the plurality of elements.

17. The photonic crystal surface light emitting device according to claim 1, wherein the planar shape of the optical element portion is polygonal.

18. The photonic crystal surface light-emitting device according to claim 1, wherein the planar shape of the optical element portion is circular or elliptical.

19. The photonic crystal surface light-emitting device according to claim 1, wherein the element includes a rim portion provided around the optical element portion.

20. The photonic crystal surface light emitting device according to claim 19, wherein there is a gap between the optical element portion and the rim portion.

21. The photonic crystal surface light emitting device according to claim 1, wherein the light emitting element portion emits a plurality of light beams toward the optical element portion.

22. The photonic crystal surface light emitting device according to claim 1, wherein the optical element portion splits the light from the light emitting element portion into a plurality of beams.

23. The photonic crystal surface light emitting device according to claim 22, wherein the direction of the chief ray of at least one of the plurality of light beams is inclined with respect to the stacking direction of the active layer and the photonic crystal layer.

24. The photonic crystal surface light emitting device according to claim 22, wherein the plurality of light beams are emitted radially from the optical element portion.

25. The photonic crystal surface light emitting device according to claim 22, wherein the light emitting element section emits the light in the stacking direction of the active layer and the photonic crystal layer.

26. A photonic crystal surface light-emitting device as described in claim 22, wherein light from the light-emitting element section includes fundamental mode light and higher-order mode light surrounding the fundamental mode light, the fundamental mode light is split into a plurality of first split light beams in the optical element section, and the higher-order mode light is emitted from the optical element section as second split light beams spatially separated from the plurality of first split light beams.

27. The photonic crystal surface light emitting device according to claim 26, further comprising a light blocking portion for blocking the second divided light.

28. A photonic crystal surface light-emitting device according to claim 22, wherein the light from the light-emitting element section includes fundamental mode light and higher-order mode light around the fundamental mode light, and a light-shielding section is provided to block the higher-order mode light.

29. The photonic crystal surface light-emitting device according to claim 22, wherein the optical element portion includes a metasurface.

30. The photonic crystal surface light-emitting element according to claim 29, wherein the metasurface has a group of pillars including a plurality of pillars arranged two-dimensionally on a reference plane.

31. The photonic crystal surface light emitting device according to claim 30, wherein the far-field pattern of light emitted from said optical element portion is a multi-point dot pattern.

32. The photonic crystal surface light-emitting element according to claim 30, wherein the pillar group includes: a first pillar; and at least one second pillar whose center is located within a distance range of 5 times the radius of the first pillar from the center of the first pillar and whose diameter differs from that of the first pillar by 50 nm or more.

33. The photonic crystal surface light-emitting device according to claim 30, wherein the light-emitting element section is provided on one surface of a substrate, and the optical element section is provided on the other surface of the substrate.

34. The photonic crystal surface light-emitting device according to claim 33, wherein the group of pillars is part of the substrate.

35. The photonic crystal surface light-emitting device according to claim 33, wherein the group of pillars is a separate member from the substrate.

36. The photonic crystal surface light-emitting device according to claim 35, wherein the optical element portion has an anti-reflection film disposed between the group of pillars and the substrate.

37. The photonic crystal surface light-emitting device according to claim 36, wherein the antireflection film has a thickness different between the portion where the pillars are arranged and the portion where the pillars are not arranged.

38. The photonic crystal surface light-emitting device according to claim 30, wherein the optical element portion has an anti-reflection film covering the pillar and / or the reference surface.

39. The photonic crystal surface light-emitting device according to claim 38, wherein the antireflection film is provided along the pillars and the reference plane.

40. The photonic crystal surface light-emitting device according to claim 38, wherein the anti-reflection film covers the tops of the pillars.

41. The photonic crystal surface light-emitting device according to claim 38, wherein the antireflection film covers a portion of the reference surface where the pillars are not provided.

42. The photonic crystal surface light-emitting device according to claim 30, wherein the optical element portion has a burying layer that buries the group of pillars.

43. The photonic crystal surface light-emitting device according to claim 42, wherein the optical element portion has an antireflection layer disposed on the burying layer.

44. A photonic crystal surface light-emitting device as described in claim 30, wherein the metasurface is designed so that a phase difference of 1 / 2 of the emission wavelength occurs between a first region corresponding to an area of ​​40% or less including the center of the light-emitting region of the light-emitting element section, and a second region corresponding to an area of ​​40% or more of the light-emitting region on the outer periphery of the first region.

45. The photonic crystal surface light-emitting element described in claim 30, wherein the light-emitting element portion emits light toward the optical element portion, and the metasurface is designed to reduce unevenness in the illuminance of the light.

46. ​​A photonic crystal surface light-emitting device as described in claim 30, wherein the light-emitting element portion emits light toward the optical element portion, and the metasurface has a plurality of pillars, each of which has an anisotropic planar shape and is arranged to reduce unevenness in the illuminance of the light.

47. A light emitting device comprising: a photonic crystal surface light emitting element including at least one element having: a light emitting element section including an active layer and a photonic crystal layer stacked on each other; and an optical element section provided on the emission side of the light emitting element section; and a mounting substrate on which the photonic crystal surface light emitting element is mounted.

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