Photodetector

Abstract

To provide a technique advantageous for efficient utilization of incident light.SOLUTION: A photodetector comprising: a wavefront control element which controls a wavefront of incident light; a photoelectric conversion element which converts received incident light into an electric signal; and a waveguide part which is provided between the wavefront control element and the photoelectric conversion element in a stacking direction, has a plurality of refraction regions having mutually different refractive indexes, and leads the incident light from the wavefront control element to the photoelectric conversion element.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present disclosure relates to light detection devices. [Background technology]

[0002] A light detection device equipped with a photoelectric conversion element can be used for various purposes, for example, as an image sensor for acquiring an image of a subject, or a distance image sensor for acquiring distance information (depth information) to an object.

[0003] Patent Document 1 discloses a polarization imaging system for acquiring a polarization image of a subject. Patent Document 2 discloses a solid-state imaging device employing a metasurface structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-51868 A [Patent Document 2] JP 2023-24079 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, by using a wavefront control element such as a metasurface structure to separate incident light into multiple light components and receiving each light component at a separate pixel of the photoelectric conversion element, it is possible to obtain received light data for each of the multiple light components.

[0006] On the other hand, it is not necessarily easy to perform separation and reception of such multiple light components with high accuracy using only a wave-front control element. If separation and direction of multiple light components in incident light is performed only by a wave-front control element, the design load of the wave-front control element increases, and it may be possible to realistically design only a wave-front control element with an insufficient function for separating and / or directing multiple light components. In an apparatus equipped with such a wave-front control element, the utilization efficiency of the incident light decreases.

[0007] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a technique that is advantageous for efficient use of incident light. [Means for solving the problem]

[0008] One aspect of the present disclosure relates to an optical detection device including a wave-front control element that controls a wavefront of incident light, a photoelectric conversion element that converts received incident light into an electrical signal, and a waveguide portion provided between the wave-front control element and the photoelectric conversion element in the stacking direction, the waveguide portion having a plurality of refractive indexes different from each other, and guiding the incident light from the wave-front control element to the photoelectric conversion element.

[0009] The wave-front control element may include a metasurface optical element.

[0010] The metasurface optical element emits at least a first light component and a second light component in incident light in different directions from each other, the photoelectric conversion element includes a first light pixel intended to receive the first light component and a second light pixel intended to receive the second light component, the multiple refractive index regions include a first refractive index region and a second refractive index region having a lower refractive index than the first refractive index region, and the waveguide portion has a multiple number of unit structure portions including the first refractive index region and the second refractive index region, and each unit structure portion may be assigned to a first light pixel and a second light pixel located adjacent to each other.

[0011] Each unit structure has a first light guiding region intended to emit a first light component from the metasurface optical element toward a first optical pixel, and a second light guiding region intended to emit a second light component from the metasurface optical element toward a second optical pixel, and each of the first light guiding region and the second light guiding region includes a first refraction region and a second refraction region surrounding the first refraction region in a planar direction perpendicular to the stacking direction, and the second refraction region may be located between the first refraction regions of the first light guiding region and the second light guiding region positioned adjacent to each other.

[0012] The first refractive region of the first light guiding region and the first refractive region of the second light guiding region may have asymmetric planar shapes in a planar direction.

[0013] Each unit structural part has a first light guiding region and a second light guiding region positioned adjacent to each other in a planar direction perpendicular to the stacking direction, and each of the first light guiding region and the second light guiding region includes a first refraction region and a second refraction region partially surrounding the first refraction region in the planar direction, and the second refraction region may be positioned partially between the first refraction regions of the first light guiding region and the second light guiding region positioned adjacent to each other.

[0014] The first refractive region of the first light guiding region and the first refractive region of the second light guiding region may have asymmetric planar shapes in a planar direction.

[0015] One or more of the refractive regions among the plurality of refractive regions may have a shape that changes in the stacking direction in a cross section along the stacking direction.

[0016] The metasurface optical element emits at least a first light component and a second light component in incident light in directions different from each other, the photoelectric conversion element includes a first light pixel intended to receive the first light component and a second light pixel intended to receive the second light component, the waveguide portion has a plurality of unit structure portions assigned to the first light pixel and the second pixel located adjacent to each other, and in a planar direction perpendicular to the stacking direction, the central positions of at least some of the plurality of unit structure portions may be offset from the central positions of the assigned first light pixel and second pixel depending on the image height of the assigned first light pixel and second pixel.

[0017] The offset amount of the central position of each of the plurality of unit feature parts from the central positions of the first light pixel and the second pixel to which it is assigned may vary continuously according to the image height of the first light pixel and the second pixel to which it is assigned.

[0018] The offset amount of the central position of each of the plurality of unit feature parts from the central positions of the first light pixel and the second pixel to which it is assigned may vary discretely depending on the image height of the first light pixel and the second pixel to which it is assigned.

[0019] The light detection device may include an on-chip lens that outputs the incident light toward the wave-front control element.

[0020] The light detection device may include a polarizer provided between the wave-front control element and the photoelectric conversion element.

[0021] The light detection device may include metal wiring provided between the wave-front control element and the photoelectric conversion element.

[0022] The light detection device may include a wavelength selection filter that selectively transmits light in a specific wavelength range of the incident light.

[0023] The photoelectric conversion element may output an electrical signal as an image signal.

[0024] The metasurface optical element may emit at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in different directions, and the photoelectric conversion element may include a first optical pixel intended to receive the first wavelength range component and a second optical pixel intended to receive the second wavelength range component.

[0025] The metasurface optical element may emit at least a first polarization in the incident light and a second polarization having a vibration direction different from the first polarization in different directions, and the photoelectric conversion element may include a first optical pixel intended to receive the first polarization and a second optical pixel intended to receive the second polarization.

[0026] The photoelectric conversion element may output an electrical signal as a sensing signal.

[0027] The metasurface optical element may emit at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in different directions, and the photoelectric conversion element may include a first optical pixel intended to receive the first wavelength range component and a second optical pixel intended to receive the second wavelength range component.

[0028] The incident light is light from an object, and the photoelectric conversion element may output an electrical signal as a distance image signal including depth information of the object.

[0029] The distance image signal may include depth information based on the ToF method. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of an image sensor. [Figure 2A] FIG. 2A is a diagram showing an XZ cross section of an example of an image sensor according to the first basic structure example. [Figure 2B] FIG. 2B is a plan view illustrating an example of a spot diameter of incident light (first light component and second light component) on the light receiving surface of a photoelectric conversion element of the image sensor in FIG. 2A. [Figure 3A] FIG. 3A is a diagram showing an XZ cross section of an example of an image sensor according to the second basic structure example. [Figure 3B] FIG. 3B is a diagram showing a YZ cross section of the image sensor shown in FIG. 3A. [Figure 3C] FIG. 3C is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 3A and 3B. [Figure 3D] FIG. 3D is a plan view illustrating the spot diameter of incident light (in this example, the first light component and the second light component) on the light receiving surface of the photoelectric conversion element of the image sensor shown in FIGS. 3A and 3B. [Figure 4A] FIG. 4A is a diagram showing an XZ cross section of an example of an image sensor according to the third basic structure example. [Figure 4B] FIG. 4B is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIG. 4A. [Figure 4C] 4C is a plan view illustrating an example of a spot diameter of incident light (first light component and second light component) on the light receiving surface of a photoelectric conversion element of the image sensor shown in FIG. 4A. [Figure 4D] FIG. 4D is a diagram showing the XZ cross section of the image sensor shown in FIGS. 4A to 4C, and illustrates a case where the first light component is obliquely (non-perpendicularly) incident on the wave-front control element. [Figure 4E] FIG. 4E is a plan view illustrating a spot diameter of incident light L (a first light component obliquely incident on the image sensor) on the light receiving surface of a photoelectric conversion element of the image sensor shown in FIG. 4D. [Figure 5A] FIG. 5A is a diagram showing an XZ cross section of the image sensor shown in FIG. 2A that does not have an aperture structure, and illustrates a case where the first light component is obliquely (non-perpendicularly) incident on the wave-front control element. [Figure 5B] FIG. 5B is a plan view illustrating a spot diameter of incident light L (a first light component obliquely incident on the image sensor) on the light receiving surface of a photoelectric conversion element of the image sensor shown in FIG. 5A. [Figure 6A]FIG. 6A is a plan view of one light receiving pixel of a photoelectric conversion element, and is a diagram for explaining robustness with respect to the incident angle of incident light L. FIG. [Figure 6B] FIG. 6B is a plan view of one light receiving pixel of a photoelectric conversion element, and is a diagram for explaining robustness with respect to the incident angle of incident light L. FIG. [Figure 7A] FIG. 7A is a plan view of one light receiving pixel of a photoelectric conversion element, and is a diagram for explaining robustness with respect to the incident angle of incident light L. FIG. [Figure 7B] FIG. 7B is a plan view of one light receiving pixel of a photoelectric conversion element, and is a diagram for explaining robustness with respect to the incident angle of incident light L. FIG. [Figure 8A] FIG. 8A is a diagram illustrating an XZ cross section of an example of the image sensor according to the first embodiment. [Figure 8B] FIG. 8B is a diagram showing a YZ cross section of the image sensor shown in FIG. 8A. [Figure 8C] FIG. 8C is a diagram showing an XY cross section of the metasurface optical element (wavefront control element) of the image sensor of FIGS. 8A and 8B. [Figure 8D] FIG. 8D is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 8A and 8B. [Figure 9A] FIG. 9A is a diagram illustrating an XZ cross section of an example of an image sensor according to the second embodiment. [Figure 9B] FIG. 9B is a diagram showing a YZ cross section of the image sensor shown in FIG. 9A. [Figure 9C] FIG. 9C is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 9A and 9B. [Figure 10A] FIG. 10A is a diagram illustrating an XZ cross section of an example of an image sensor according to the third embodiment. [Figure 10B] FIG. 10B is a diagram showing a YZ cross section of the image sensor shown in FIG. 10A. [Figure 10C] FIG. 10C is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 10A and 10B. [Figure 11A]FIG. 11A is a diagram illustrating an XZ cross section of an example of an image sensor according to the fourth embodiment. [Figure 11B] FIG. 11B is a diagram showing a YZ cross section of the image sensor shown in FIG. 11A. [Figure 11C] FIG. 11C is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 11A and 11B. [Figure 12A] FIG. 12A is a diagram illustrating an XZ cross section of an example of an image sensor according to the fifth embodiment. [Figure 12B] FIG. 12B is a diagram showing a YZ cross section of the image sensor shown in FIG. 12A. [Figure 12C] FIG. 12C is a diagram showing an XY cross section of an aperture structure (unit structure) of the image sensor shown in FIGS. 12A and 12B. [Figure 13A] FIG. 13A is a diagram showing an XZ cross section of an example of an opening structure according to the sixth embodiment. [Figure 13B] FIG. 13B is a diagram showing an XZ cross section of another example of the opening structure according to the sixth embodiment. [Figure 14A] FIG. 14A is a diagram showing an XY cross section of an example of an opening structure (unit structure) according to the seventh embodiment. [Figure 14B] FIG. 14B is a diagram showing an XY cross section of another example of the aperture structure (unit structure) according to the seventh embodiment. [Figure 14C] FIG. 14C is a diagram showing an XY cross section of another example of an aperture structure (unit structure) according to the seventh embodiment. [Figure 15A] FIG. 15A is a diagram showing an XZ cross section of an example of an image sensor according to the eighth embodiment. [Figure 15B] FIG. 15B is a diagram showing a YZ cross section of the image sensor shown in FIG. 15A. [Figure 15C] FIG. 15C is a diagram showing an XY cross section of the aperture structure of the image sensor shown in FIGS. 15A and 15B. [Figure 16A] FIG. 16A is a diagram showing an XZ cross section of an example of an image sensor according to the ninth embodiment. [Figure 16B]FIG. 16B is a diagram showing a YZ cross section of the image sensor shown in FIG. 16A. [Figure 16C] FIG. 16C is a plan view of the image sensor of FIGS. 16A and 16B. [Figure 17A] FIG. 17A is a diagram showing an XZ cross section of an example of an image sensor according to the tenth embodiment. [Figure 17B] FIG. 17B is a diagram showing a YZ cross section of the image sensor shown in FIG. 17A. [Figure 17C] FIG. 17C is a plan view of the image sensor of FIGS. 17A and 17B. [Figure 18A] FIG. 18A is a diagram showing an XZ cross section of an example of an image sensor according to the eleventh embodiment. [Figure 18B] FIG. 18B is a diagram showing a YZ cross section of the image sensor shown in FIG. 18A. [Figure 18C] FIG. 18C is a diagram showing an XY cross section of the wire grid polarizer (particularly, a unit polarizer) shown in FIGS. 18A and 18B. [Figure 19A] FIG. 19A is a diagram showing an XZ cross section of another example of the image sensor according to the eleventh embodiment. [Figure 19B] FIG. 19B is a diagram showing a YZ cross section of the image sensor shown in FIG. 19A. [Figure 19C] FIG. 19C is a diagram showing an XY cross section of the photonic crystal polarizer (particularly, the unit polarizer) shown in FIGS. 19A and 19B. [Figure 20A] FIG. 20A is a diagram showing an XZ cross section of an example of an image sensor according to the twelfth embodiment. [Figure 20B] FIG. 20B is a diagram showing a YZ cross section of the image sensor shown in FIG. 20A. [Figure 21A] FIG. 21A is a diagram showing an XZ cross section of an example of an image sensor according to the thirteenth embodiment. [Figure 21B] FIG. 21B is a diagram showing a YZ cross section of the image sensor shown in FIG. 21A. [Figure 21C] FIG. 21C is a diagram showing an XY cross section of the wavelength selective filter shown in FIGS. 21A and 21B. [Figure 22] FIG. 22 is a diagram showing an XZ cross section of an example of an image sensor according to the fourteenth embodiment. [Diagram 23] FIG. 23 is a diagram showing an XZ cross section of an example of an image sensor according to the fifteenth embodiment. [Figure 24] FIG. 24 is a diagram showing an XZ cross section of an example of an image sensor according to the sixteenth embodiment. [Diagram 25] FIG. 25 is a diagram showing an XZ cross section of an example of an image sensor according to the seventeenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Exemplary embodiments of the present disclosure will now be described with reference to the drawings.

[0032] In the following, unless otherwise specified, a case will be described in which the disclosed technology is applied to an image sensor (solid-state image sensor) that can be applied to an imaging camera system, etc. However, the application of the disclosed technology is not limited, and the disclosed technology may be applied to other light detection devices (e.g., sensors, etc.) that can be used for purposes other than imaging.

[0033] Each element in the drawings is shown diagrammatically or conceptually. Therefore, the characteristics of each element in the drawings, such as the size and shape, may differ from the characteristics of the corresponding element in reality. The size ratio between elements in the drawings may also differ from the size ratio between corresponding elements in an actual device. Furthermore, the size and shape of each element and the size ratio between elements do not necessarily match between drawings, and one or more specific elements may be exaggerated in each drawing.

[0034] In the following description, the X, Y, and Z directions are perpendicular to each other. As an example, the X direction may correspond to the horizontal direction, the Y direction may correspond to the vertical direction (height direction), and the Z direction may correspond to the depth direction. Furthermore, the XY plane / section is a surface extending in the X and Y directions, the XZ plane / section is a surface extending in the X and Z directions, and the YZ plane / section is a surface extending in the Y and Z directions.

[0035] Fig. 1 is a schematic diagram showing a configuration example of an image sensor 1. In Fig. 1, a light transmission control section 10 and a photoelectric conversion element 11 are shown as viewed obliquely, and an optical system OP is shown as viewed from the side.

[0036] The image sensor 1 can typically be configured by a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor, but can be configured by any imaging device.

[0037] The image sensor 1 receives light from an external subject (target) and outputs information about the light as an electrical signal.

[0038] The image sensor 1 shown in Fig. 1 includes an optical system OP, a light transmission control unit 10, and a photoelectric conversion element 11. The optical system OP includes a lens that collects incident light L from a subject. The incident light L that passes through the optical system OP may include front incident light La that travels in a direction along the optical axis (optical axis direction) and oblique incident light Lb that travels in a direction oblique to the optical axis. In the example shown in Fig. 1, the Z direction coincides with the optical axis direction.

[0039] The photoelectric conversion element 11 includes a plurality of light receiving pixels PX that receive incident light L. In the example shown in FIG. 1, the plurality of light receiving pixels PX are two-dimensionally arranged in the X and Y directions, and the photoelectric conversion element 11 has a rectangular light receiving surface with sides extending in the X and Y directions as a whole. When the traveling direction of the chief ray of the incident light L incident on the image sensor 1 coincides with the optical axis direction, the light receiving pixel PX located at the center (0% of the image height) of the photoelectric conversion element 11 receives the front incident light La. On the other hand, the light receiving pixel PX located away from the center of the photoelectric conversion element 11 (for example, the light receiving pixel PX located at the end of the photoelectric conversion element 11 (for example, 100% of the image height)) receives the oblique incident light Lb.

[0040] The photoelectric conversion element 11 is an element that converts received incident light into an electrical signal. Each light receiving pixel PX of the photoelectric conversion element 11 can typically be configured with a photodiode (e.g., a Si (silicon) semiconductor material) that converts light into an electric current using a semiconductor pn junction. Since the absorption rate (sensitivity) of the incident light of each light receiving pixel PX can change depending on the wavelength of the incident light L, the light absorption coefficient of each light receiving pixel PX is not necessarily large.

[0041] The light transmission control unit 10 is disposed in the optical path between the optical system OP and the photoelectric conversion element 11, and is provided so as to cover a plurality of light receiving pixels PX (light receiving surfaces) of the photoelectric conversion element 11. The light transmission control unit 10 has a function of guiding a plurality of light components in the incident light L to the corresponding light receiving pixels PX, and can have various configurations as described below.

[0042] For example, a portion of the optical transfer control unit 10 that covers the light-receiving pixel PX located at the center of the photoelectric conversion element 11 focuses the frontal incident light La on the light-receiving pixel PX located at the center of the photoelectric conversion element 11. On the other hand, a portion of the optical transfer control unit 10 that covers the light-receiving pixel PX located at the end of the photoelectric conversion element 11 focuses the obliquely incident light Lb on the light-receiving pixel PX located at the end of the photoelectric conversion element 11. In this way, each portion of the optical transfer control unit 10 guides a desired light component contained in the incident light L incident at various angles to the corresponding light-receiving pixel PX.

[0043] The above-mentioned image sensor 1 (for example, the light transmission control section 10) can have various configurations. A typical structural example of the image sensor 1 will be described below.

[0044] [First basic structure example] Fig. 2A is a diagram showing an XZ cross section of an example of the image sensor 1 according to the first basic structure example. Fig. 2B is a plan view showing an example of a spot diameter of incident light (first light component L1 and second light component L2) on the light receiving surface of the photoelectric conversion element 11 of the image sensor 1 in Fig. 2A.

[0045] Fig. 2A shows a portion (particularly, a unit structure) of image sensor 1, and the unit structure shown in Fig. 2A is repeatedly provided in each of the X direction and the Y direction in image sensor 1. Similarly, Fig. 2B shows a portion (particularly, a unit structure) of photoelectric conversion element 11, and the unit structure shown in Fig. 2B is repeatedly provided in each of the X direction and the Y direction in photoelectric conversion element 11.

[0046] 2A and 2B exemplarily show a case where incident light L including a first light component L1 and a second light component L2 is perpendicularly incident on the image sensor 1 (particularly the wave-front control element 20).

[0047] 2A includes a wave-front control element 20, a waveguide 21, and a photoelectric conversion element 11, which are stacked in the Z direction. The wave-front control element 20 and the waveguide 21 are provided as a light transmission control section 10.

[0048] The wave-front control element 20 is an element that exerts a function of controlling the wavefront of the incident light L based on optical characteristics such as diffraction and refraction, and can be configured by, for example, a lens, a diffraction grating, or a metasurface optical element, but is not limited to these optical elements. In the example shown in Fig. 2A, the wave-front control element 20 separates a plurality of light components (at least a first light component L1 and a second light component L2) from the incident light L and outputs them in directions different from each other.

[0049] The photoelectric conversion element 11 includes a first photopixel PX1 intended to receive a first light component L1, and a second photopixel PX2 intended to receive a second light component L2.

[0050] The waveguide 21 provided between the wave-front control element 20 and the photoelectric conversion element 11 in the stacking direction (Z direction) transmits the light components L1 and L2 of the incident light L from the wave-front control element 20 to the photoelectric conversion element 11.

[0051] The waveguide 21 of this example is configured by the first refractive region 31 having a single composition (i.e., a single refractive index). Therefore, the light components L1 and L2 of the incident light L from the wave-front control element 20 basically travel linearly within the waveguide 21 without being affected by refraction, diffraction, or the like, and are incident on the light receiving pixels PX1 and PX2 of the photoelectric conversion element 11.

[0052] Therefore, in the image sensor 1 of this example, basically, optical separation, collection, and pupil correction of the light components in the incident light L are performed only by the wave-front control element 20. Therefore, the wave-front control element 20 of this example is required to have a structure capable of appropriately realizing such optical separation, collection, and pupil correction.

[0053] However, it is not necessarily easy to design a wave-front control element 20 that can appropriately exhibit such various functions. As a result, for example, the light-collecting function of the entire image sensor 1 is weakened, and the spot diameter of the incident light (in this example, the first light component L1 and the second light component L2) on each of the light-receiving pixels PX1 and PX2 may become large (see FIG. 2B).

[0054] [Second basic structure example] In this basic structure example, elements that are the same as or correspond to those in the first basic structure example described above are given the same reference numerals, and detailed description thereof will be omitted.

[0055] Fig. 3A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the second basic structure example. Fig. 3B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 3A. Fig. 3C is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 3A and 3B. Fig. 3D is a plan view illustrating a spot diameter of incident light (in this example, the first light component L1 and the second light component L2) on the light receiving surface of the photoelectric conversion element 11 of the image sensor 1 shown in Figs. 3A and 3B.

[0056] In FIG. 3C, the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 3A is indicated by the reference symbol "IIIA", and the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 3B is indicated by the reference symbol "IIIB".

[0057] Figures 3A to 3D show unit structures. In the image sensor 1 of this example, the unit structures shown in Figures 3A to 3D are repeatedly provided in each of the X direction and the Y direction. Figures 3A to 3D also show, by way of example, a case in which incident light L including a first light component L1 and a second light component L2 is perpendicularly incident on the image sensor 1 (particularly the wave-front control element 20).

[0058] The image sensor 1 shown in FIGS. 3A to 3D has a similar configuration to the image sensor 1 shown in FIGS. 2A and 2B described above, but the waveguide section 21 has an aperture structure section 22.

[0059] The opening structure 22 has a plurality of refractive regions (in this example, a first refractive region 31 and a second refractive region 32) having different refractive indices, and has an opening structure in which a region having a relatively high refractive index is partially or entirely surrounded by a region having a relatively low refractive index.

[0060] 3C includes a first refraction region 31 constituting a central region in the XY cross section, and a second refraction region 32 surrounding the entire central region (first refraction region 31) in the XY cross section. The central region (first refraction region 31) of the unitary structure of the opening structure 22 can be made of a dielectric material, and the second refraction region 32 is made of a material exhibiting a lower refractive index than the first refraction region 31. In this way, the unitary structure of the opening structure 22 includes a central region (first refraction region 31) exhibiting a relatively high refractive index, and a peripheral region (second refraction region 32) exhibiting a relatively low refractive index.

[0061] 3A to 3D, the first refraction region 31 constitutes not only the central region of the aperture structure 22 but also the portion of the waveguide 21 other than the aperture structure 22. Therefore, the portion of the waveguide 21 other than the peripheral region (second refraction region 32) of the aperture structure 22 is constituted by the first refraction region 31. However, the waveguide 21 shown in FIGS. 3A to 3D is merely an example, and the portion of the waveguide 21 other than the aperture structure 22 does not have to be constituted by the first refraction region 31, and may be constituted by, for example, any other composition.

[0062] In this example, only one aperture structure of the aperture structure section 22 is provided for each unit structure, and one aperture structure of the aperture structure section 22 is assigned to a plurality of light receiving pixels PX constituting the unit structure. In the example shown in Fig. 3A to Fig. 3D, two light receiving pixels PX1 and PX2 adjacent to each other in the X direction constitute a unit structure, so that one aperture structure of the aperture structure section 22 is provided for each two-pixel region corresponding to the two light receiving pixels PX1 and PX2. That is, as shown in Fig. 3C, in the two-pixel region covering the two light receiving pixels PX1 and PX2 (unit pixel group) of the aperture structure section 22, the central region is constituted by the first refraction region 31, and the peripheral region is constituted by the second refraction region 32.

[0063] In the aperture structure 22 having the above-mentioned configuration, the traveling speed of light is relatively slow in the central region (first refraction region 31) exhibiting a high refractive index, and is relatively fast in the peripheral region (second refraction region 32) exhibiting a low refractive index. Therefore, the aperture structure 22 exerts an optical function of collecting light from the wavefront control element 20 on a desired light receiving pixel PX of the photoelectric conversion element 11 by aperture diffraction caused by the refractive index difference between the central region and the peripheral region. In this way, the image sensor 1 of this example having the aperture structure 22 exerts a high light collecting effect, and the spot diameter of the incident light (first light component L1 and second light component L2) on the light receiving surface of the photoelectric conversion element 11 becomes small (see FIG. 3D).

[0064] The smaller light spot diameter on each light receiving pixel PX improves robustness against CRA (Chief Ray Angle), thereby improving the sensor sensitivity of the photoelectric conversion element 11 and the uniformity of the light utilization efficiency of the image sensor 1 as a whole.

[0065] The CRA referred to here is represented by the angle that the principal ray makes with respect to the optical axis of the image sensor 1, and is an index indicating the angle of incidence of the incident light L with respect to the image sensor 1. In general, the higher the CRA, the larger the angle of incidence of the incident light L with respect to the image sensor 1, and the more likely it is that light leakage (crosstalk) to adjacent pixels will occur. In contrast, according to the image sensor 1 of this example, crosstalk is unlikely to occur even in the case of a high CRA due to the light collecting effect and spot diameter reduction effect brought about by the aperture structure 22.

[0066] As described above, according to the image sensor 1 of this example, the functions of separating, collecting, and correcting the pupil of a desired light component in the incident light L are realized not only by the wave-front control element 20 but also by the aperture structure 22. Therefore, the image sensor 1 of this example is advantageous in realizing high performance of various functions while reducing the design load of the wave-front control element 20, compared to the case where these various functions are realized only by the wave-front control element 20 as in the first basic structure example described above.

[0067] 3A to 3D are merely examples, and the image sensor 1 may have other configurations. Therefore, the shapes of the elements constituting the image sensor 1 (for example, the aperture structure of the aperture structure portion 22) are not limited.

[0068] In the example shown in FIGS. 3A to 3D, the aperture structure 22 is provided adjacent to the wave-front control element 20 in the Z direction, but the aperture structure 22 may be provided at a position spaced apart from the wave-front control element 20 in the Z direction.

[0069] The wave-front control element of the imaging device of the above-mentioned Patent Document 1 does not have a pupil correction function. Also, since the imaging device of Patent Document 1 does not have the above-mentioned aperture structure 22, the function of separating and focusing the light components in the incident light must be performed only by the wave-front control element. Therefore, in the imaging device of Patent Document 1, the design load of the wave-front control element is high, and it is assumed that the function of separating and focusing the light components in the incident light is insufficient with the wave-front control element actually designed.

[0070] Similarly, in the solid-state imaging device of the above-mentioned Patent Document 2, the functions of separating and focusing the light components in the incident light must be performed solely by the metasurface structure. Therefore, in the solid-state imaging device of Patent Document 2, the design load of the metasurface structure is high, and it is expected that the metasurface structure actually designed will only perform an insufficient function.

[0071] [Third basic structure example] In this basic structure example, elements that are the same as or correspond to those in the first and second basic structure examples described above are given the same reference numerals, and detailed explanations thereof will be omitted.

[0072] Fig. 4A is a diagram showing an XZ cross section of an example of an image sensor 1 according to a third basic structure example. Fig. 4B is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Fig. 4A. Fig. 4C is a plan view illustrating a spot diameter of incident light (first light component L1 and second light component L2) on the light receiving surface of the photoelectric conversion element 11 of the image sensor 1 shown in Fig. 4A.

[0073] In FIG. 4B, the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 4A is indicated by the symbol "IVA."

[0074] 4A to 4C has a similar configuration to the image sensor 1 shown in the above-mentioned FIGS. 3A to 3D, but each unit structure of the aperture structure 22 (see FIG. 4B) has a first light guiding region R1 and a second light guiding region R2. The first light guiding region R1 and the second light guiding region R2 are located adjacent to each other in the XY plane direction (particularly the X direction) perpendicular to the stacking direction (the Z direction).

[0075] The first light guiding region R1 is intended to emit a first light component L1 from the wavefront control element 20 toward a first light pixel PX1, and the second light guiding region R2 is intended to emit a second light component L2 from the wavefront control element 20 toward a second light pixel PX2.

[0076] Each of the first light guiding region R1 and the second light guiding region R2 includes a first refraction region 31 constituting a central region, and a second refraction region 32 surrounding the first refraction region 31 in a planar direction perpendicular to the stacking direction (Z direction). In this example, a boundary region 32a, which is a part of the second refraction region 32, is located between the first refraction regions 31 of the first light guiding region R1 and the second light guiding region R2 that are adjacent to each other. The boundary region 32a completely separates the first refraction regions 31 of the first light guiding region R1 and the second light guiding region R2 from each other in the opening structure 22.

[0077] In this manner, in this example, "an aperture structure in which a region having a relatively high refractive index is surrounded by a region having a relatively low refractive index" is provided for each pixel region, and one aperture structure of the aperture structure portion 22 is assigned to each light receiving pixel PX. That is, as shown in Fig. 4B, in one pixel region of the aperture structure portion 22 covering one light receiving pixel PX, the central region is constituted by the first refractive region 31, and the peripheral region is constituted by the second refractive region 32 (including the boundary region 32a).

[0078] According to the image sensor 1 of this example, the width in the X direction of the first refraction region 31 in the aperture structure 22 (i.e., the aperture width) is narrower than the width in the X direction of the first refraction region 31 in the third basic structure example described above (see FIG. 3C). Therefore, according to the image sensor 1 of this example, the light collecting effect on the light receiving surface of the photoelectric conversion element 11 is improved, and the spot diameter of the incident light (the first light component L1 and the second light component L2) on the light receiving surface is smaller than the examples shown in FIGS. 3A to 3D (see FIGS. 3D and 4C). As a result, the robustness against CRA is improved, and the uniformity of the sensor sensitivity and the light utilization efficiency of the photoelectric conversion element 11 is improved.

[0079] Fig. 4D is a diagram showing the XZ cross section of the image sensor 1 shown in Fig. 4A to Fig. 4C, and illustrates a case where the first light component L1 is obliquely (non-perpendicularly) incident on the wave-front control element 20. Fig. 4E is a plan view illustrating a spot diameter of the incident light L (the first light component L1 obliquely incident on the image sensor 1) on the light receiving surface of the photoelectric conversion element 11 of the image sensor 1 shown in Fig. 4D.

[0080] Fig. 5A is a diagram showing the XZ cross section of the image sensor 1 shown in Fig. 2A that does not have the aperture structure 22, and illustrates a case where the first light component L1 is obliquely (non-perpendicularly) incident on the wave-front control element 20. Fig. 5B is a plan view illustrating a spot diameter of the incident light L (the first light component L1 obliquely incident on the image sensor 1) on the light receiving surface of the photoelectric conversion element 11 of the image sensor 1 shown in Fig. 5A.

[0081] According to the image sensor 1 shown in FIG. 4D, Fresnel reflection occurs in the boundary region 32a between the first light guiding region R1 and the second light guiding region R2, so that light leakage between adjacent light receiving pixels PX1 and PX2 can be reduced. In this manner, in the image sensor 1 shown in FIG. 4D, the spot diameter on the photoelectric conversion element 11 is reduced and the spot position is corrected by the aperture structure 22, so that the first light component L1 is accurately incident on the intended light receiving pixel PX1 and is unlikely to be incident on the adjacent light receiving pixel PX2. On the other hand, in the image sensor 1 shown in FIG. 5A, the spot diameter is not reduced and the spot position is not corrected by the aperture structure 22, so that the first light component L1 may also be incident on the light receiving pixel PX2 adjacent to the intended light receiving pixel PX1 (see FIG. 5B).

[0082] By providing the aperture structure of the aperture structure portion 22 for each pixel region in this manner, the light collecting effect and the spot diameter reducing effect on the photoelectric conversion element 11 can be further improved.

[0083] 4A, in the image sensor 1 of this example, the aperture structure 22 is provided away from the wave-front control element 20 in the Z direction. This allows the desired light components L1 and L2 in the incident light L to enter the aperture structure 22 in a state where the effect of separation by the wave-front control element 20 is promoted. Therefore, each of the light components L1 and L2 efficiently enters the corresponding light guiding regions R1 and R2, and the light collecting effect and the spot diameter reduction effect on the photoelectric conversion element 11 can be enhanced.

[0084] In addition, when the aperture structure 22 is disposed near the wave-front control element 20, the first light component L1 and the second light component L2 may be incident on the aperture structure 22 before separation by the wave-front control element 20 is sufficiently promoted. In this case, not only the first light component L1 but also a relatively large amount of the second light component L2 is incident on the first light guiding region R1 of the aperture structure 22, and similarly, not only the second light component L2 but also a relatively large amount of the first light component L1 is incident on the second light guiding region R2. Therefore, from the viewpoint of suppressing crosstalk between the first light pixel PX1 and the second light pixel PX2, it is preferable to provide a sufficient Z-direction distance between the wave-front control element 20 and the aperture structure 22.

[0085] [Fourth basic structure example] In this basic structure example, elements that are the same as or correspond to those in the above-mentioned first to third basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0086] 6A to 7B are plan views of one light receiving pixel PX of the photoelectric conversion element 11, and are diagrams for explaining robustness against the incident angle of incident light L. Figs. 6A and 7A show an example of a light receiving spot Sp on the light receiving pixel PX when a light component (e.g., the first light component L1) in the incident light L received by the light receiving pixel PX is incident in a perpendicular direction to the photoelectric conversion element 11. Figs. 6B and 7B show an example of a light receiving spot Sp on the light receiving pixel PX when a light component (e.g., the first light component L1) in the incident light L received by the light receiving pixel PX is incident in an oblique direction to the photoelectric conversion element 11.

[0087] 6A and 6B show a non-offset structure in which the center positions of the unit structures of the aperture structure 22 are located on the same vertical line extending along the Z direction as the center positions of the unit structures (first photopixel PX1 and second photopixel PX2) of the corresponding light-receiving pixels PX. On the other hand, Figs. 7A and 7B show a case in which the arrangement of the unit structures of the aperture structure 22 is devised according to the image height. That is, the example shown in Figs. 7A and 7B shows an offset structure in which the center positions of the unit structures of the aperture structure 22 are offset in the image height direction from the center positions of the unit structures of the corresponding light-receiving pixels PX.

[0088] In general, the relative incidence angle of the incident light L (light component) to the photoelectric conversion element 11 can change depending on the arrangement position (image height) of the corresponding light receiving pixel PX. For example, when a light component incident on a light receiving pixel PX located close to the optical axis has an incidence angle close to the vertical direction, a light component incident on a light receiving pixel PX located away from the optical axis may have an incidence angle in an oblique direction that is relatively large with respect to the optical axis direction.

[0089] On the other hand, the incident position of the incident light L (corresponding light component) on the light receiving pixel PX can change depending on the relative incident angle of the incident light L with respect to the photoelectric conversion element 11 (see FIGS. 6A to 7B).

[0090] 6A and 6B, when a light component received by a light receiving pixel PX is incident on the photoelectric conversion element 11 in a vertical direction, the light component is incident on the center of the corresponding light receiving pixel PX and received therein (see FIG. 6A). On the other hand, in the example shown in FIG. 6A and 6B, when a light component received by a light receiving pixel PX is incident on the photoelectric conversion element 11 in an oblique direction, the spot position on the light receiving surface shifts laterally, and the light component is incident on a position close to one end of the corresponding light receiving pixel PX and received therein (see FIG. 6B).

[0091] 7A and 7B, when the light component received by the light receiving pixel PX is incident on the photoelectric conversion element 11 in a perpendicular direction, the light component is incident on a position close to one end of the corresponding light receiving pixel PX and received therein (see FIG. 7A). In this case, when the light component received by the light receiving pixel PX is incident on the photoelectric conversion element 11 in an oblique direction, the spot position on the light receiving surface shifts laterally, but even if the degree of the lateral shift is relatively large, the light component is still incident on the corresponding light receiving pixel PX and received therein (see FIG. 7B).

[0092] Therefore, the robust range Rb, which is the permissible shift amount of the light receiving spot Sp on the light receiving pixel PX caused by the desired light component being obliquely incident on the photoelectric conversion element 11, is larger in the example shown in Figures 7A and 7B than in the example shown in Figures 6A and 6B. That is, it can be said that the case where the arrangement of the unit structures of the aperture structure 22 is designed according to the image height (see Figures 7A and 7b) is more robust with respect to the incidence angle (CRA) of the incident light L than the case where such design is not performed (see Figures 6A and 6B). Therefore, according to the image sensor 1 including the aperture structure 22 (see Figures 7A and 7b) having an arrangement designed according to the image height, crosstalk between adjacent pixels can be effectively reduced even in a high CRA region.

[0093] As described above, by providing an aperture structure 22 in the waveguide 21 (see Figures 3A to 4E and 6A to 7B), the desired light components in the incident light L can be effectively received by the corresponding light receiving pixel PX, and the incident light L can be efficiently utilized.

[0094] The above-mentioned basic structure examples merely show schematic configurations of typical examples of the disclosed technology, and may be modified as appropriate, or may be combined with other basic structure examples. For example, the above-mentioned fourth basic structure example (see, in particular, Figures 7A and 7B) may be combined with the above-mentioned second basic structure example (see, Figures 3A to 3D) and third basic structure example (see, Figures 4A to 4E).

[0095] Various embodiments that are application forms and development forms of the above-mentioned basic structure example will be described below. In each of the following embodiments, an image sensor 1 having a metasurface optical element as the wave-front control element 20 will be described. However, the technology of each of the following embodiments can also be applied to an image sensor 1 having a wave-front control element 20 other than a metasurface optical element.

[0096] [First embodiment] In this embodiment, elements that are the same as or correspond to those in the above-mentioned first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0097] Fig. 8A is a diagram showing an XZ cross section of an example of the image sensor 1 according to the first embodiment. Fig. 8B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 8A. Fig. 8C is a diagram showing an XY cross section of the metasurface optical element 40 (wavefront control element 20) of the image sensor 1 of Figs. 8A and 8B. Fig. 8D is a diagram showing an XY cross section of the aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 8A and 8B.

[0098] 8C and 8D, the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 8A is indicated by the reference symbol "VIIIA", and the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 8B is indicated by the reference symbol "VIIIB".

[0099] The image sensor 1 shown in FIGS. 8A to 8D has a configuration similar to that of the image sensor 1 shown in FIGS. 3A to 3D described above, but has a metasurface optical element 40 as the wave-front control element 20.

[0100] The metasurface optical element 40 has meta-atoms 41, which are numerous (plural) microscopic structures arranged two-dimensionally in the X and Y directions, and structural peripheral parts 42 occupying the areas between the meta-atoms 41. The meta-atoms 41 are arranged based on a certain rule for achieving the desired optical properties of the metasurface optical element 40, and impart meta-physical properties to electromagnetic waves in general. These meta-atoms 41 have the arrangement, shape, and other properties required for achieving the desired optical functions, such as light separation, light collection, and pupil correction, required in the image sensor 1.

[0101] The multiple meta-atoms 41 that form the metasurface optical element 40 are arranged in an XY plane that extends approximately parallel to the light receiving surface of the photoelectric conversion element 11, and have a refractive index greater than that of the peripheral portion 42 of the structure.

[0102] The meta-atoms 41 can have any configuration. Typically, they are made of a dielectric material, but they may also be made of metal or resin. There is no limit to the materials that can be used to make each meta-atom 41. Examples of materials that can be used to make the meta-atoms 41 include amorphous silicon (α-Si), polycrystalline silicon (Poly-Si), germanium, titanium oxide (TiO 2 ), niobium oxide, tantalum oxide, aluminum oxide, hafnium oxide, silicon nitride (SiN, Si 3 N 4 Each meta-atom 41 may be made of any of silicon oxide, silicon nitride oxide, silicon carbide, silicon oxide carbide, silicon nitride carbide, zirconium oxide, gallium nitride (GaN), gallium arsenide (GaAs), and indium phosphide (InP).

[0103] The shape of each meta-atom 41 is not limited, and may be, for example, a prism, a cylinder, a polygon, or a topologically higher-order shape. The manufacturing method of each meta-atom 41 is not limited, and may be, for example, by processing a substrate material or providing a laminate on a substrate, thereby forming the meta-atom 41.

[0104] The structural periphery 42 may also have any configuration, for example it may be provided as a space or may be made of a solid material such as silicon dioxide.

[0105] The metasurface optical element 40 of this embodiment separates two or more light components in the incident light L containing a plurality of separable light components, and outputs them in different directions, and spatially separates the two or more light components so that they are incident on the corresponding light receiving pixels PX, respectively. The metasurface optical element 40 of the example shown in Figures 8A to 8D separates and outputs the first light component L1 and the second light component L2 in the incident light L so that the first light component L1 and the second light component L2 are received by the first light pixel PX1 and the second light pixel PX2, respectively.

[0106] 8A to 8D show an example in which the incident light L is incident perpendicularly to the metasurface optical element 40, but the metasurface optical element 40 also exhibits a similar function when the incident light L is incident obliquely to the metasurface optical element 40. In addition, the example shown in Figures 8A to 8D shows an example in which the metasurface optical element 40 separates two light components (a first light component L1 and a second light component L2) from the incident light L, but the metasurface optical element 40 may separate three or more light components from the incident light L and emit them.

[0107] As in this embodiment, the aperture structure 22 of the waveguide 21 can be suitably combined with the metasurface optical element 40. That is, by combining the light modulation function of the metasurface optical element 40 with the light diffraction function of the aperture structure 22, it is possible to appropriately separate multiple desired light components in the incident light L and efficiently receive the light by the corresponding light receiving pixels PX.

[0108] The image sensor 1 of this embodiment, in which the aperture structure 22 and the metasurface optical element 40 are combined in this manner, can also perform the functions of light separation, light collection, pupil correction, and photoelectric conversion, similar to the image sensor 1 of Figures 3A to 3D described above, and can efficiently utilize the incident light L.

[0109] [Second embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first embodiment and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0110] Fig. 9A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the second embodiment. Fig. 9B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 9A. Fig. 9C is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 9A and 9B.

[0111] In FIG. 9C, the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 9A is indicated by the reference symbol "IXA", and the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 9B is indicated by the reference symbol "IXB".

[0112] 9A to 9C has a configuration similar to that of the image sensor 1 shown in the above-mentioned FIGS. 4A to 4E, but has a metasurface optical element 40 as the wavefront control element 20. The metasurface optical element 40 emits at least a first light component L1 and a second light component L2 in the incident light L in directions different from each other.

[0113] Each unit structure part of the opening structure 22 (see Figure 9C) has a first light guiding region R1 and a second light guiding region R2, and each of the light guiding regions R1, R2 has a first refraction region 31 that constitutes a central region and a second refraction region 32 that surrounds the first refraction region 31.

[0114] The first refraction region 31 of the first light guiding region R1 and the second light guiding region R2 of each unit structure are completely separated from each other by the boundary region 32a, and in this embodiment in particular, have a cross-sectional shape (XY cross-sectional shape) that is line-symmetrical with respect to the boundary region 32a. Thus, in this embodiment, a common opening structure in which the first refraction region 31 is surrounded by the second refraction region 32 is provided for each light receiving pixel PX, and a unique opening structure is assigned to each light receiving pixel PX.

[0115] According to the image sensor 1 of this embodiment, as with the image sensor 1 shown in Figs. 4A to 4E described above, it is possible to effectively collect light on the photoelectric conversion element 11 and correct the light collecting position. As a result, the spot diameter of the incident light (the first light component L1 and the second light component L2) on the light receiving surface of the photoelectric conversion element 11 is reduced, and it is possible to reduce the leakage of light to the light receiving pixel PX adjacent to the target light receiving pixel PX. As a result, the robustness against CRA is improved, and the uniformity of the sensor sensitivity and light utilization efficiency of the photoelectric conversion element 11 is improved.

[0116] 9A to 9C, each of the first light guiding region R1 and the second light guiding region R2 has a rectangular (square) planar shape, and the first refraction region 31 of each of the light guiding regions R1 and R2 also has a rectangular (square) planar shape. However, the planar shapes of each of the light guiding regions R1 and R2 and each of the first refraction regions 31 are not limited, and may have a planar shape other than a rectangular shape (for example, a polygonal shape or a circular shape).

[0117] [Third embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first and second embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0118] Fig. 10A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the third embodiment. Fig. 10B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 10A. Fig. 10C is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 10A and 10B.

[0119] 10C, the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 10A is indicated by the symbol "XA", and the cross-sectional line showing the cross-section of the image sensor 1 in FIG. 10B is indicated by the symbol "XB".

[0120] The image sensor 1 shown in FIGS. 10A to 10C has a similar configuration to the image sensor 1 shown in FIGS. 9A to 9C described above, but the planar shape of the first refraction region 31 is different between the first light guiding region R1 and the second light guiding region R2.

[0121] In the example shown in FIGS. 10A to 10C, the first light guiding region R1, the second light guiding region R2, and the first refraction region 31 of each of the first light guiding region R1 and the second light guiding region R2 have a rectangular cross-sectional shape (XY cross-sectional shape).

[0122] However, in each unit structure of the opening structure 22, the boundary region 32a located between the first refraction region 31 of the first light guiding region R1 and the second light guiding region R2 protrudes more toward the second light guiding region R2 than toward the first light guiding region R1. Therefore, the first refraction region 31 of the first light guiding region R1 and the first refraction region 31 of the second light guiding region R2 have an asymmetric (non-axisymmetric) planar shape in a plane (XY cross section; particularly, X direction) perpendicular to the stacking direction (Z direction).

[0123] In the example shown in FIG. 10A to FIG. 10C, the center of the XY cross section of the entire first light guiding region R1 coincides with the center of the XY cross section of the first refraction region 31 of the first light guiding region R1. Meanwhile, the center of the XY cross section of the entire second light guiding region R2 does not coincide with the center of the XY cross section of the first refraction region 31 of the second light guiding region R2. The centers of the XY cross sections of the first light guiding region R1 and the second light guiding region R2 are located on the same straight line extending along the Z direction as the centers (pixel centers Cp) of the corresponding light receiving pixels PX1 and PX2. Therefore, when the incident light L is incident on the metasurface optical element 40 in the vertical direction, even if the spot center of the first light component L1 coincides with the center of the first light pixel PX1, the spot center Cs of the second light component L2 may not coincide with the center of the second light pixel PX2.

[0124] In this manner, by adjusting the central position of the first refraction region 31 of the first light guiding region R1 and / or the second light guiding region R2 of the opening structure 22, it is possible to more effectively adjust the spot position of the incident light L (light components L1, L2) on the light receiving pixel PX.

[0125] [Fourth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to third embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0126] Fig. 11A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the fourth embodiment. Fig. 11B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 11A. Fig. 11C is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 11A and 11B.

[0127] 11C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 11A is indicated by reference symbol "XIA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 11B is indicated by reference symbol "XIB".

[0128] 11A to 11C has a similar configuration to the image sensor 1 shown in FIGS. 9A to 9C described above, but the first refraction regions 31 of the first light guiding region R1 and the second light guiding region R2 are not completely separated from each other. That is, each of the first light guiding region R1 and the second light guiding region R2 includes the first refraction region 31 and the second refraction region 32 that partially surrounds the first refraction region 31 in the XY plane direction. The second refraction region 32 (i.e., the boundary protruding region 32b) is partially located between the first refraction regions 31 of the first light guiding region R1 and the second light guiding region R2 of each unit structure of the opening structure 22.

[0129] That is, at the boundary between the first light guiding region R1 and the second light guiding region R2, instead of the boundary region 32a (see FIG. 9C) that completely separates the first refraction regions 31, two boundary protrusion regions 32b (second refraction regions 32) that protrude in the opposing directions (Y direction) are provided. These boundary protrusion regions 32b are provided apart from each other in the opposing directions (Y direction), and a slit region 31a (first refraction region 31) is provided between the boundary protrusion regions 32b. Therefore, the first refraction region 31 is partially separated by the boundary protrusion region 32b between the first light guiding region R1 and the second light guiding region R2, but is connected to each other via the slit region 31a.

[0130] Each boundary protrusion region 32b in the example shown in FIG. 11C has a triangular XY cross-sectional shape, and the size in the X direction in which the first light guiding region R1 and the second light guiding region R2 are arranged gradually decreases in the direction toward the boundary protrusion region 32b provided at the opposing position (Y direction).

[0131] According to the image sensor 1 of the present embodiment, in which the first refraction region 31 has a slit structure between the first light guiding region R1 and the second light guiding region R2, the spot diameter of the incident light (the first light component L1 and the second light component L2) on the light receiving surface can be reduced. In particular, the image sensor 1 of the present embodiment can also move the spot position (spot center position) of the incident light L on the light receiving surface closer to the center of each light receiving pixel PX.

[0132] [Fifth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to fourth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0133] Fig. 12A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the fifth embodiment. Fig. 12B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 12A. Fig. 12C is a diagram showing an XY cross section of an aperture structure 22 (unit structure) of the image sensor 1 shown in Figs. 12A and 12B.

[0134] 12C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 12A is indicated by reference symbol "XIIA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 12B is indicated by reference symbol "XIIB".

[0135] The image sensor 1 shown in Figures 12A to 12C has a configuration similar to that of the image sensor 1 shown in Figures 11A to 11C described above, but the first refraction region 31 has an asymmetric planar shape between the first light guiding region R1 and the second light guiding region R2 of the unit structure portion of the opening structure portion 22.

[0136] That is, each of the two boundary protrusion regions 32b that partially separate the first refraction region 31 between the first light guiding region R1 and the second light guiding region R2 has an asymmetric (non-line symmetric) planar shape with respect to the X direction. Therefore, the first refraction regions 31 of the first light guiding region R1 and the second light guiding region R2 of the unit structure portion of the opening structure 22 also have an asymmetric planar shape in the XY cross section (particularly in the X direction).

[0137] In the image sensor 1 of this embodiment, the first refraction region 31 has a slit region 31a between the first light guiding region R1 and the second light guiding region R2, and the spot diameter of the incident light (the first light component L1 and the second light component L2) on the light receiving surface can be reduced.

[0138] Particularly in this embodiment, the spot position of the incident light L on the light receiving surface of the photoelectric conversion element 11 varies depending on the shapes and sizes of the first refraction region 31 (slit region 31a) and the second refraction region 32 (boundary protrusion region 32b). Therefore, by adjusting the shapes and sizes of the first refraction region 31 (slit region 31a) and the second refraction region 32 (boundary protrusion region 32b), it is possible to perform pupil correction for adjusting the spot position of the incident light (first light component L1 and second light component L2) on the light receiving surface.

[0139] In particular, by making the first refraction region 31 and the boundary protrusion region 32b asymmetric between the first light guiding region R1 and the second light guiding region R2, it is possible to make the spot positions different between the first light pixel PX1 and the second light pixel PX2. For example, as shown in Fig. 12A, it is also possible to adjust the spot position of the first light component L1 to the pixel center of the first light pixel PX1, while adjusting the spot position (spot center Cs) of the second light component L2 to an offset position deviated from the pixel center Cp of the second light pixel PX2.

[0140] Although the boundary protrusion region 32b in the example shown in FIG. 12C has a triangular XY cross-sectional shape, the boundary protrusion region 32b may have any other shape (cross-sectional shape).

[0141] [Sixth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to fifth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0142] Fig. 13A is a diagram showing an XZ cross section of an example of the opening structure 22 according to the sixth embodiment, and Fig. 13B is a diagram showing an XZ cross section of another example of the opening structure 22 according to the sixth embodiment.

[0143] The configuration of the opening structure 22 of the waveguide 21 is not limited, and the first refraction region 31 and the second refraction region 32 of the opening structure 22 can have any shape (for example, any XZ cross-sectional shape). That is, the shapes of the multiple refraction regions (the first refraction region 31 and the second refraction region 32) included in the opening structure 22 may or may not change in the stacking direction (Z direction) in a cross section (for example, an XZ cross section) along the stacking direction.

[0144] For example, as shown in Fig. 13A, the first refraction region 31 of the unit structure of the aperture structure 22 may have a step-shaped XZ cross section, or may have an XY cross section whose area increases stepwise from the metasurface optical element 40 side toward the photoelectric conversion element 11 side. Alternatively, as shown in Fig. 13B, the first refraction region 31 of the unit structure of the aperture structure 22 may have an XY cross section whose area increases continuously (successively) from the metasurface optical element 40 side toward the photoelectric conversion element 11 side.

[0145] The XZ cross section of the first refraction region 31 in Fig. 13B corresponds to a case where the height of each step is very small (infinitely small) in the XZ cross section of the step-shaped first refraction region 31 as shown in Fig. 13A. In the example shown in Fig. 13B, the first refraction region 31 of the opening structure 22 has a semicircular XZ cross section, but the first refraction region 31 may have an XZ cross section of any other shape.

[0146] In this way, when the shapes of the refractive regions 31, 32 of the aperture structure 22 change in the stacking direction (Z direction) in a cross section in the stacking direction (for example, an XZ cross section and / or a YZ cross section), it is possible to give the aperture structure 22 optical properties as a lens. Therefore, by adjusting the cross-sectional shapes of the refractive regions 31, 32 in the aperture structure 22, it is possible to adjust the spot position and / or spot diameter of the incident light (first light component L1 and second light component L2) on the photoelectric conversion element 11.

[0147] As described above, according to this embodiment, it is possible to provide an image sensor 1 having excellent light-collecting performance and pupil correction performance.

[0148] [Seventh embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to sixth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0149] Fig. 14A is a diagram showing an XY cross section of an example of the opening structure 22 (unit structure) according to the seventh embodiment. Fig. 14B is a diagram showing an XY cross section of another example of the opening structure 22 (unit structure) according to the seventh embodiment. Fig. 14C is a diagram showing an XY cross section of another example of the opening structure 22 (unit structure) according to the seventh embodiment.

[0150] The first refractive region 31 that constitutes the central region of the unit structure of the opening structure 22 may have any shape and may have a non-rectangular cross-section (XY cross-section) in a planar direction perpendicular to the stacking direction (Z direction).

[0151] The first refractive region 31 may have, for example, a polygonal XY cross section (an octagon in the example shown in FIG. 14A) or an XY cross section with rounded corners as shown in FIG. 14B.

[0152] Furthermore, the first refraction region 31 constituting the central region of the unit structure of the opening structure 22 does not necessarily have to be entirely surrounded by the second refraction region 32. For example, as shown in Fig. 14C, four corners of the unit structure of the opening structure 22 may be constituted by the first refraction region 31, and the first refraction regions 31 may be connected to each other between unit structures adjacent to each other in the X direction and / or Y direction.

[0153] In this way, the shape of the planar cross section (XY cross section) of the first refractive region 31 is not limited, and may be determined appropriately based on the manufacturing characteristics (e.g., ease of manufacturing) and other characteristics required for the image sensor 1 (e.g., the aperture structure portion 22).

[0154] [Eighth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to seventh embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0155] Fig. 15A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the eighth embodiment. Fig. 15B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 15A. Fig. 15C is a diagram showing an XY cross section of the aperture structure 22 of the image sensor 1 shown in Figs. 15A and 15B.

[0156] 15C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 15A is indicated by reference symbol "XVA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 15B is indicated by reference symbol "XVB".

[0157] 15A to 15C has a similar configuration to the image sensor 1 shown in Fig. 8A to 8D described above, but the aperture center point Pm, which is the center point of the unit structure of the aperture structure 22, does not coincide with the two-pixel center point Pw, which is the center point of the corresponding unit pixel group Pu. That is, the aperture center point Pm of the unit structure of the aperture structure 22 and the two-pixel center point Pw of the corresponding unit pixel group Pu are not located on a common straight line extending along the Z direction.

[0158] In this way, in a plane (XY plane) perpendicular to the stacking direction, the center positions (aperture center points Pm) of at least some of the unit structures of the aperture structure 22 are offset from the center position (two-pixel center point Pw) of the corresponding unit pixel group Pu in accordance with the image height of the unit pixel group Pu. Here, it is preferable that the offset direction of the aperture center point Pm from the two-pixel center point Pw coincides with the direction of the image height of the assigned unit pixel group Pu.

[0159] 15A to 15C, the center in the X direction of the unit pixel group Pu (first optical pixel PX1 and second optical pixel PX2) assigned to the unit structure of the aperture structure 22 is represented as a "two-pixel center Cw", and the two-pixel center point Pw is located on the two-pixel center Cw. Furthermore, the center in the X direction of the unit structure of the aperture structure 22 is represented as an "aperture center Cm", and the aperture center point Pm is located on the aperture center Cm.

[0160] The distance (shift amount) in the X direction between the center of the unit structure part of the aperture structure 22 (see aperture center Cm) and the center of the assigned unit pixel group Pu (two-pixel center Cw) is represented as the “offset amount OS”. Even if this offset amount OS is “zero (0)” for the unit structure part of the aperture structure 22 and the unit pixel group Pu at the 0% image height (optical axis position), it increases as the image height increases.

[0161] There is no limitation on the way of changing the offset amount OS. The offset amount of the center position (aperture center point Pm) of each unit structure part of the aperture structure 22 from the center position (two-pixel center point Pw) of the assigned unit pixel group Pu may be changed continuously (monotonically) or discretely (stepwise) according to the image height of the unit pixel group Pu. The offset amount OS of each unit structure part of the aperture structure 22 may be determined based on other criteria.

[0162] By setting the offset amount OS of each unit structure of the aperture structure 22 according to the image height of the unit pixel group Pu allocated in this manner, the incident light L can be effectively made incident on the light receiving surface of the target light receiving pixel PX. By such pupil correction, the desired light components (the first light component L1 and the second light component L2) can be made incident with high efficiency even on the light receiving pixel PX located near the end of the image sensor 1, and the light receiving performance of the entire light receiving pixel PX can be made uniform.

[0163] Note that the aperture center point Pm of the unit structure portion of the aperture structure 22 assigned to only some of the light receiving pixels PX of the photoelectric conversion element 11 may be offset with respect to the two-pixel center point Pw of the corresponding unit pixel group Pu.

[0164] Generally, in the range close to the optical axis of the image sensor 1, the incident angle θ of the incident light L is close to 0°, so the desired light components L1, L2 can be made to be incident on the corresponding light receiving pixels PX1, PX2 with high accuracy without offsetting the aperture center point Pm with respect to the two-pixel center point Pw. On the other hand, since the incident angle θ of the incident light L gradually increases as the light receiving pixel PX moves away from the optical axis, it can be effective to offset the aperture center point Pm with respect to the two-pixel center point Pw in order to make the desired light components L1, L2 incident on the corresponding light receiving pixels PX1, PX2.

[0165] Therefore, for light receiving pixels PX located within a certain distance range from the optical axis, it is not necessary to offset the aperture center point Pm from the two-pixel center point Pw in the unit structure part of the corresponding aperture structure 22. On the other hand, for light receiving pixels PX located beyond a certain distance from the optical axis, the aperture center point Pm may be offset from the two-pixel center point Pw in the unit structure part of the corresponding aperture structure 22. Even in this case, the desired light components L1, L2 can be efficiently incident on the corresponding light receiving pixels PX1, PX2 throughout the entire photoelectric conversion element 11, and uniformity of the light receiving performance of the entire light receiving pixels PX can be promoted.

[0166] [Ninth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to eighth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0167] Fig. 16A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the ninth embodiment, Fig. 16B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 16A, and Fig. 16C is a plan view of the image sensor 1 of Figs. 16A and 16B.

[0168] In FIG. 16C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 16A is indicated by reference symbol "XVIA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 16B is indicated by reference symbol "XVIB".

[0169] 16A to 16C has a similar configuration to the image sensor 1 shown in the above-described FIGS. 8A to 8D, but is provided with an on-chip lens 50. The on-chip lens 50 includes a plurality of microlenses, and emits incident light L (including a first light component L1 and a second light component L2) toward the metasurface optical element 40 (wavefront control element 20).

[0170] 16A to 16C is laminated on the metasurface optical element 40 and is provided on the opposite side to the photoelectric conversion element 11 via the metasurface optical element 40. In particular, in this embodiment, one microlens is assigned to each light receiving pixel PX (i.e., one light receiving pixel PX) of the photoelectric conversion element 11, and one microlens is arranged in one pixel region of the on-chip lens 50.

[0171] There are no limitations on the specific configuration and material (composition) of the on-chip lens 50. The material (composition) of the on-chip lens 50 is, for example, a dielectric material such as Si, α-Si, or SiO 2 , SiN, Si 3 N 4 , SiC, TiO 2 , GaN, GaAs, and InP can be appropriately selected.

[0172] In the image sensor 1 of this embodiment, the incident light L is incident on the metasurface optical element 40 after being subjected to pupil correction by the on-chip lens 50 provided on the incident side of the metasurface optical element 40 (wavefront control element 20).

[0173] Therefore, even if the angle of incidence of the incident light L on the image sensor 1 (particularly the on-chip lens 50) is large, the on-chip lens 50 allows the angle of incidence of the incident light L on the metasurface optical element 40 to approach 0 degrees.

[0174] As a result, even if the incident light L is obliquely incident on the image sensor 1 (particularly the on-chip lens 50), the focusing positions (focused spots) of the light components L1 and L2 on the photoelectric conversion element 11 are brought closer to the desired positions (e.g., central positions) of the corresponding light receiving pixels PX1 and PX2. As a result, it is possible to reduce light leakage (crosstalk) between the adjacent light receiving pixels PX1 and PX2.

[0175] [Tenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to ninth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0176] Fig. 17A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the tenth embodiment. Fig. 17B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 17A. Fig. 17C is a plan view of the image sensor 1 shown in Figs. 17A and 17B.

[0177] In FIG. 17C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 17A is indicated by reference symbol "XVIIA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 17B is indicated by reference symbol "XVIIB".

[0178] The image sensor 1 of this embodiment has a similar configuration to the image sensor 1 of the above-described ninth embodiment, but one microlens of the on-chip lens 50 corresponds to two or more light receiving pixels PX. That is, light components in the incident light L that has passed through each microlens of the on-chip lens 50 are incident on the two or more associated light receiving pixels PX.

[0179] In the on-chip lens 50 shown in FIGS. 17A to 17C, each microlens 59 is arranged so as to correspond to a unit pixel group (that is, two light receiving pixels PX (one first light pixel PX1 and one second light pixel PX2)).

[0180] In the image sensor 1 of this embodiment, the incident light L is also incident on the metasurface optical element 40 after being subjected to pupil correction by the on-chip lens 50 provided on the incident side of the metasurface optical element 40 (wavefront control element 20). As a result, even if the incident light L is incident on the image sensor 1 at an angle, the focusing positions of the light components L1 and L2 on the photoelectric conversion element 11 are brought closer to the desired positions of the corresponding light receiving pixels PX1 and PX2, and light leakage (crosstalk) between adjacent light receiving pixels PX1 and PX2 can be reduced.

[0181] [Eleventh embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to tenth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0182] Fig. 18A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the eleventh embodiment. Fig. 18B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 18A. Fig. 18C is a diagram showing an XY cross section of the wire grid polarizer 56 (particularly, unit polarizer 55n) shown in Figs. 18A and 18B.

[0183] Fig. 19A is a diagram showing an XZ cross section of another example of image sensor 1 according to the eleventh embodiment. Fig. 19B is a diagram showing a YZ cross section of image sensor 1 shown in Fig. 19A. Fig. 19C is a diagram showing an XY cross section of photonic crystal polarizer 57 (particularly unit polarizer 55n) shown in Figs. 19A and 19B.

[0184] In Fig. 18C, the cross-sectional line showing the cross-section of the image sensor 1 in Fig. 18A is indicated by the reference symbol "XVIIIA," and the cross-sectional line showing the cross-section of the image sensor 1 in Fig. 18B is indicated by the reference symbol "XVIIIB." In Fig. 19C, the cross-sectional line showing the cross-section of the image sensor 1 in Fig. 19A is indicated by the reference symbol "XIXA," and the cross-sectional line showing the cross-section of the image sensor 1 in Fig. 19B is indicated by the reference symbol "XIXB."

[0185] 8A to 8D, but further includes a polarizer 55 provided between the metasurface optical element 40 (wavefront control element 20) and the photoelectric conversion element 11. The polarizer 55 (wire grid polarizer 56, photonic crystal polarizer 57) shown in Fig. 18A to 19C is provided in the waveguide 21, particularly between the aperture structure 22 and the photoelectric conversion element 11 (particularly at a position close to the light receiving surface of the photoelectric conversion element 11).

[0186] The metasurface optical element 40 of this embodiment separates at least a first polarized light Lp1 (first light component L1) and a second polarized light Lp2 (second light component L2) in the incident light L and outputs them in directions different from each other. In Figures 18A to 18C, the arrows indicated by the symbols "Lp1" and "Lp2" indicate the vibration directions of the first polarized light Lp1 and the second polarized light Lp2, respectively, and the vibration directions of the first polarized light Lp1 and the second polarized light Lp2 are perpendicular to each other.

[0187] 18A to 18C, a wire grid polarizer 56 is provided as the polarizer 55. In the example shown in Figures 19A to 19C, a photonic crystal polarizer 57 is provided as the polarizer 55.

[0188] The polarizer 55 includes a plurality of unit polarizers 55n associated with the plurality of light-receiving pixels PX, respectively. Each of the plurality of unit polarizers 55n selectively passes polarized light corresponding to the associated light-receiving pixel PX.

[0189] The first wire grid polarizer region 56-1, which is the pixel region on the left side of the unit polarizer 55n in Fig. 18C, is positioned so as to cover the corresponding first optical pixel PX1 and selectively transmits only the first polarized light Lp1 (first optical component L1) to be incident on the corresponding first optical pixel PX1. On the other hand, the second wire grid polarizer region 56-2, which is the pixel region on the right side of the unit polarizer 55n in Fig. 18C, is positioned so as to cover the corresponding second light receiving pixel PX2 and selectively transmits only the second polarized light Lp2 (second optical component L2) to be incident on the corresponding second light receiving pixel PX2.

[0190] Similarly, first photonic crystal polarizer region 57-1, which is a pixel region on the left side of unit polarizer 55n in Fig. 19C, is positioned so as to cover corresponding first optical pixel PX1 and selectively transmits only first polarized light Lp1 to be incident on corresponding first optical pixel PX1. Meanwhile, second photonic crystal polarizer region 57-2, which is a pixel region on the right side of unit polarizer 55n in Fig. 19C, is positioned so as to cover corresponding second light receiving pixel PX2 and selectively transmits only second polarized light Lp2 to be incident on corresponding second light receiving pixel PX2.

[0191] There are no limitations on the specific configuration and material (composition) of wire grid polarizer 56 shown in Figures 18A to 18C. Similarly, there are no limitations on the specific configuration and material (composition) of photonic crystal polarizer 57 shown in Figures 19A to 19C.

[0192] The wire grid polarizer 56 may have a structure in which metal and dielectric materials are periodically arranged in a one-dimensional direction in a region (one pixel region) corresponding to each light receiving pixel PX. In this case, the material (composition) of the metal portion of the wire grid polarizer 56 may be appropriately selected from, for example, Au, Ag, Cu, Al, AlCu, and W. The material (composition) of the dielectric portion of the wire grid polarizer 56 may be, for example, Si, α-Si, SiO2 , SiN, Si 3 N 4 , SiC, TiO 2 , GaN, GaAs, and InP can be appropriately selected.

[0193] Each pixel region of the wire grid polarizer 56 including the periodic metal-dielectric array structure transmits only the polarized light component in the same direction as the periodic direction of the metal-dielectric.

[0194] Photonic crystal polarizer 57 can have a structure in which a plurality of dielectric layers having different refractive indices are periodically arranged in a one-dimensional direction (Z direction) in a region (one pixel region) corresponding to each light receiving pixel PX. In this case, the material (composition) of the dielectric of photonic crystal polarizer 57 can be, for example, Si, α-Si, SiO 2 , SiN, Si 3 N 4 , SiC, TiO 2 , GaN, GaAs, InP, Ta 2 O 3 and Nb 2 O 5 It is possible to appropriately select from among the above.

[0195] Each pixel region of photonic crystal polarizer 57 including a periodic arrangement structure of a plurality of dielectric materials having different refractive indices transmits only the polarized light component perpendicular to the concave and convex lines.

[0196] In the image sensor 1 of this embodiment, polarized light from the metasurface optical element 40 is incident on the polarizer 55 (wire grid polarizer 56, photonic crystal polarizer 57), and only the polarized light that is transmitted through the polarizer 55 is incident on each light receiving pixel PX of the photoelectric conversion element 11. Each pixel region of the polarizer 55 basically does not allow the transmission of polarized light that is not originally intended to be received by the associated light receiving pixel PX, and transmits only polarized light that is originally intended.

[0197] As a result, only the corresponding desired linearly polarized light component can be more reliably incident on each light receiving pixel PX of the photoelectric conversion element 11, and the purity of the polarized light received by each light receiving pixel PX is increased.

[0198] [Twelfth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to eleventh embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0199] Fig. 20A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the twelfth embodiment, and Fig. 20B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 20A.

[0200] 8A to 8D, a metal wiring 60 is provided between the metasurface optical element 40 (wavefront control element 20) and the photoelectric conversion element 11. The metal wiring 60 shown in FIGS. 20A and 20B is provided in the waveguide 21, and in particular, is provided between the aperture structure 22 and the photoelectric conversion element 11.

[0201] The metal wiring 60 is made of a metal material, and in addition to its inherent wiring function of conducting electricity, it has a light blocking function of not transmitting light by reflecting and / or absorbing light.

[0202] It is possible to reduce light leakage (crosstalk) between adjacent light receiving pixels PX by arranging at least a part of such metal wiring 60 in accordance with the boundary between the light receiving pixels PX of the photoelectric conversion element 11. In other words, by arranging the metal wiring 60 in a position that covers the boundary between the light receiving pixels PX, the metal wiring 60 can block the progression of light to an adjacent light receiving pixel PX that is not originally intended.

[0203] [Thirteenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to twelfth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0204] Fig. 21A is a diagram showing an XZ cross section of an example of an image sensor 1 according to the thirteenth embodiment. Fig. 21B is a diagram showing a YZ cross section of the image sensor 1 shown in Fig. 21A. Fig. 21C is a diagram showing an XY cross section of the wavelength selection filter 63 shown in Figs. 21A and 21B.

[0205] In FIG. 21C, the cross-sectional line showing the cross-section of image sensor 1 in FIG. 21A is indicated by reference symbol "XXIA", and the cross-sectional line showing the cross-section of image sensor 1 in FIG. 21B is indicated by reference symbol "XXIB".

[0206] The image sensor 1 of this embodiment has a configuration similar to that of the image sensor 1 shown in FIGS. 8A to 8D described above, but further includes a wavelength selection filter 63 that selectively transmits light in a desired specific wavelength range out of the incident light L.

[0207] The wavelength selection filter 63 is disposed so as to cover the entire light receiving surface (light receiving pixel PX) of the photoelectric conversion element 11, and light received by the light receiving surface is light that is incident on the photoelectric conversion element 11 after passing through the wavelength selection filter 63. Therefore, the entirety of each unit pixel group Pu (first photopixel PX1 and second photopixel PX2) to which the unit structure portion of the aperture structure 22 is assigned is covered by the wavelength selection filter 63.

[0208] The wavelength selection filter 63 shown in FIGS. 21A to 21C is provided so as to cover the metasurface optical element 40 on the side opposite to the photoelectric conversion element 11 with respect to the metasurface optical element 40.

[0209] 21A to 21C, the position of the wavelength-selecting filter 63 in the stacking direction (Z direction) is not limited to the examples shown in Fig. 21A to 21C, and may be any position upstream of the photoelectric conversion element 11 (particularly the light receiving surface) based on the traveling direction of the incident light L. Therefore, the wavelength-selecting filter 63 may be disposed between the metasurface optical element 40 (wavefront control element 20) and the aperture structure 22, or the wavelength-selecting filter 63 may be disposed between the aperture structure 22 and the photoelectric conversion element 11.

[0210] The wavelength range of light that can be transmitted through the wavelength selection filter 63 is typically included in the visible light wavelength range, but may be included in a wavelength range shorter than visible light (ultraviolet wavelength range) or may be included in a wavelength range longer than visible light (for example, infrared wavelength range). The wavelength selection filter 63 shown in Figures 21A to 21C is configured with a color filter that transmits light included in the visible light wavelength range (for example, RGB light).

[0211] Of the incident light L incident on the wavelength-selecting filter 63 , the light components that cannot be transmitted through the wavelength-selecting filter 63 (non-transmitted light) are reflected by the surface of the wavelength-selecting filter 63 or absorbed by the wavelength-selecting filter 63 .

[0212] The wavelength-selecting filter 63 may have a single composition throughout and selectively transmit light in a common wavelength range throughout. Alternatively, the wavelength-selecting filter 63 may have multiple types of regions having different compositions from each other and selectively transmit light in different wavelength ranges in each of the multiple types of regions. Such multiple types of regions of the wavelength-selecting filter 63 are typically provided to correspond to each of the multiple light-receiving pixels PX of the photoelectric conversion element 11.

[0213] The wavelength-selective filter 63 is typically made of a dielectric material or an absorptive material, but may be made of any other material or combination of materials.

[0214] In this embodiment, the wavelength transmission characteristics of the wavelength selection filter 63 are determined so that the transmission wavelength range of the wavelength selection filter 63 corresponds to the wavelength range of the light components intended to be received by the photoelectric conversion element 11 (each light receiving pixel PX). In this case, light components not intended to be received by the photoelectric conversion element 11 cannot or are difficult to transmit through the wavelength selection filter 63, and as a result, they are not or are difficult to receive by the photoelectric conversion element 11. Therefore, it is possible to more reliably receive light in the desired wavelength range at each light receiving pixel PX of the photoelectric conversion element 11.

[0215] [Fourteenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to thirteenth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0216] Fig. 22 is a diagram showing an XZ cross section of an example of an image sensor 1 according to the fourteenth embodiment. The image sensor 1 shown in Fig. 22 is configured as a spectroscopic imaging device (for example, an RGB image sensor) 1A.

[0217] The image sensor 1 of this embodiment is configured as a 2D imaging device in which an electrical signal output from the photoelectric conversion element 11 is used as an image signal. The image sensor 1 acquires and outputs a captured image, particularly of unpolarized light (i.e., light including multiple types of light components that vibrate in various directions).

[0218] The metasurface optical element 40 (wavefront control element 20) of this embodiment functions as a color filter provided in a general imaging device, and separates a plurality of light components having different wavelength ranges in the incident light L and outputs them in different directions. More specifically, the metasurface optical element 40 outputs at least a first wavelength range component in the incident light L and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in different directions. Meanwhile, the photoelectric conversion element 11 includes a first optical pixel intended to receive the first wavelength range component and a second optical pixel intended to receive the second wavelength range component.

[0219] 22, the metasurface optical element 40 separates the first to third imaging light components Lv1, Lv2, and Lv3 (the first to third light components L1, L2, and L3) in the incident light L, and emits them toward the first to third optical pixels PX1, PX2, and PX3, respectively. Here, the first to third imaging light components Lv1, Lv2, and Lv3 are typically light whose main wavelength ranges are the R (red), G (green), and B (blue) wavelength ranges, respectively, but may be light in other wavelength ranges.

[0220] In the example shown in FIG. 22, the first to third imaging light components Lv1, Lv2, and Lv3 are incident on three light receiving pixels PX adjacent to each other in the X direction, but may be incident on three light receiving pixels PX adjacent to each other in the Y direction.

[0221] Even when the image sensor 1 is used as a 2D imaging device as described above, the image sensor 1 is provided with the aperture structure 22, so that the spot diameters on the corresponding light receiving pixels PX of the multiple light components Lv1, Lv2, and Lv3 in the incident light L can be reduced. As a result, the image sensor 1 exhibits excellent robustness and good uniformity of sensor sensitivity, and can acquire and output high-quality captured images with reduced crosstalk (color mixing).

[0222] [Fifteenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to fourteenth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0223] Fig. 23 is a diagram showing an XZ cross section of an example of an image sensor 1 according to the fifteenth embodiment. The image sensor 1 shown in Fig. 23 is configured as a polarization imaging device (polarization image sensor) 1B.

[0224] The image sensor 1 of this embodiment is also configured as a 2D imaging device (image capture device) in which the electrical signal output from the photoelectric conversion element 11 is used as an image signal, and in particular, selectively receives polarized light (i.e., light vibrating in a specific direction) to obtain and output a captured image.

[0225] The metasurface optical element 40 (wavefront control element 20) of this embodiment functions as a polarizer that is equipped in a typical polarization imaging device, separating multiple light components with different vibration directions in the incident light L and emitting them in different directions.

[0226] 23 separates at least a first polarized light Lp1 and a second polarized light Lp2 having a vibration direction different from that of the first polarized light Lp1 in the incident light L and outputs them in directions different from each other. The photoelectric conversion element 11 includes a first optical pixel PX1 intended to receive the first polarized light Lp1 and a second optical pixel PX2 intended to receive the second polarized light Lp2.

[0227] Such an image sensor 1 can have a configuration similar to that of the image sensor 1 shown in Figures 18A to 18D described above, but the polarizer 55 (wire grid polarizer 56, photonic crystal polarizer 57) is not provided in the example shown in Figure 23. That is, the desired polarized light Lp1, Lp2 can be separated from the incident light L and guided to a specific light receiving pixel PX by only the metasurface optical element 40 (wavefront control element 20).

[0228] Although FIG. 23 illustrates only two types of polarized light (first polarized light Lp1 and second polarized light Lp2) separated from the incident light L, the metasurface optical element 40 can also separate three or more types of polarized light from the incident light L. The metasurface optical element 40 may have a structure in which a unit pixel region is a four-pixel region capable of transmitting each of four types of polarized light oscillating in four directions (0°, 45°, 90°, and 135°), and a plurality of such unit pixel regions are arranged in each of the X direction and the Y direction. According to an image sensor 1 (see FIG. 23) including such a metasurface optical element 40, images of four types of polarized light oscillating in each of the four directions can be obtained in one shot, enabling imaging with high real-time performance.

[0229] Even when the image sensor 1 is used as a 2D polarization imaging device as described above, the image sensor 1 is provided with the aperture structure 22, thereby making it possible to reduce the spot diameters on the corresponding light-receiving pixels PX1, PX2 of the polarized light Lp1, Lp2 separated from the incident light L. As a result, the image sensor 1 exhibits excellent robustness and good uniformity of sensor sensitivity, and is capable of acquiring and outputting high-quality polarization-captured images with reduced crosstalk.

[0230] [Sixteenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to fifteenth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0231] Fig. 24 is a diagram showing an XZ cross section of an example of the image sensor 1 according to the sixteenth embodiment. The image sensor 1 shown in Fig. 24 is configured as a spectroscopic sensing device 1C.

[0232] The image sensor 1 of this embodiment is configured as a 2D sensing device, and in particular receives and detects unpolarized light separated from incident light L from a sensing target.

[0233] The metasurface optical element 40 of this embodiment exerts a function (spectroscopic function) as a spectroscope (such as a diffraction grating) provided in a general sensing device, and separates a plurality of types of light components having different wavelength ranges in the incident light L and emits them in different directions. That is, the metasurface optical element 40 emits at least a first wavelength range component and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in the incident light L in different directions. The photoelectric conversion element 11 includes a first optical pixel intended to receive the first wavelength range component and a second optical pixel intended to receive the second wavelength range component.

[0234] The spectroscopic sensing device 1C shown in Figure 24 is common to the spectroscopic imaging device 1A shown in Figure 22 described above in terms of device configuration and operation, but differs from the spectroscopic imaging device 1A of Figure 22 in that the light reception results are used for sensing purposes, whereas the light reception results are used for image generation purposes.

[0235] That is, the metasurface optical element 40 of the example shown in Figure 24 separates the incident light L into first to third imaging light components Lv1, Lv2, and Lv3 (e.g., RGB light) and emits them toward the first to third optical pixels PX1, PX2, and PX3, respectively.

[0236] Even when the image sensor 1 is used as a 2D sensing device as described above, the image sensor 1 is provided with the aperture structure 22, thereby making it possible to reduce the spot diameters on the light receiving pixels PX corresponding to the multiple light components Lv1, Lv2, and Lv3 in the incident light L. As a result, the image sensor 1 exhibits excellent robustness, good sensor sensitivity, and uniform light utilization efficiency, enabling highly accurate sensing.

[0237] [Seventeenth embodiment] In this embodiment, elements that are the same as or correspond to those in the above-described first to sixteenth embodiments and first to fourth basic structure examples are given the same reference numerals, and detailed description thereof will be omitted.

[0238] Fig. 25 is a diagram showing an XZ cross section of an example of an image sensor 1 according to the seventeenth embodiment. The image sensor 1 shown in Fig. 25 is configured as a sensing device 1D.

[0239] The image sensor 1 of this embodiment is configured as a 3D sensing device (three-dimensional sensing device; for example, a ToF (Time of Flight) sensor), and receives and detects incident light L that is light from a sensing target.

[0240] The metasurface optical element 40 (wavefront control element 20) of this embodiment exerts a function (light-collecting function) as a lens (such as an on-chip lens) that a general 3D sensing device has, and can collect incident light L on each light-receiving pixel PX of the photoelectric conversion element 11. That is, the traveling direction of the incident light L from the sensing target is adjusted by the metasurface optical element 40, and the incident light L is effectively guided to the light-receiving pixel PX that corresponds to the incident position on the metasurface optical element 40.

[0241] The photoelectric conversion element 11 of the image sensor 1 used as a 3D sensing device outputs an electrical signal indicating received light data of the incident light L as a distance image signal including depth information of the object. The "depth information" referred to here is information indicating the unevenness of the object, and by analyzing the distance image signal, it is possible to obtain information regarding the unevenness of the object's surface (the surface irradiated with the incident light L).

[0242] Such a distance image signal may include depth information of the object based on any method, and may include depth information based on the ToF method as an example. The ToF method is a method for detecting the distance to the object based on the flight time of light. Typically, the time from when light is emitted toward the object until the reflected light of the light from the object reaches the 3D sensing device (particularly the photoelectric conversion element 11) is measured, and the distance between the object and the 3D sensing device is obtained based on the measured time.

[0243] Therefore, the calculation unit (not shown) receives an electrical signal (output signal) from the photoelectric conversion element 11, obtains the "flight time from emission to reception of incident light L" based on the output signal, and obtains the "distance between the target and the image sensor 1" based on the flight time. Note that the light emitting device (not shown) that emits the incident light L may be included in the image sensor 1, or may be provided separately from the image sensor 1. The calculation unit may obtain information on the light emission timing of the light emitting device from the light emitting device or another device (for example, a device that controls the light emitting device).

[0244] 24 has a configuration similar to that of the image sensor 1 of each of the above-mentioned embodiments, and a metasurface optical element 40, a waveguide 21 (including an aperture structure 22), and a photoelectric conversion element 11 are arranged to be stacked in the Z direction. When incident light L from an object enters the image sensor 1, the light is collected by the metasurface optical element 40, and then the light collection degree is further improved by the aperture structure 22, and the incident light L is then received by the corresponding light receiving pixel PX.

[0245] Even when the image sensor 1 is used as a 3D sensing device as described above, the image sensor 1 is provided with the aperture structure 22, so that the spot diameters on the corresponding light receiving pixels PX of the multiple light components Lv1, Lv2, and Lv3 in the incident light L can be reduced. As a result, the image sensor 1 exhibits excellent robustness, good sensor sensitivity, and uniform light utilization efficiency, enabling highly accurate sensing.

[0246] It should be noted that the embodiments and modifications disclosed in this specification are merely illustrative and should not be construed as limiting in all respects. The above-mentioned embodiments and modifications can be omitted, substituted, and modified in various forms without departing from the scope and spirit of the appended claims. For example, the above-mentioned embodiments and modifications may be combined in whole or in part, and embodiments other than those described above may be combined with the above-mentioned embodiments or modifications. In addition, the effects of the present disclosure described in this specification are merely illustrative, and other effects may be obtained.

[0247] The technical category embodying the above technical idea is not limited. For example, the above technical idea may be embodied by a computer program for causing a computer to execute one or more procedures (steps) included in a method for manufacturing or using the above device. The above technical idea may also be embodied by a non-transitory recording medium readable by a computer on which such a computer program is recorded.

[0248] [Note] The present disclosure may also have the following configuration.

[0249] [Item 1] A wavefront control element for controlling a wavefront of incident light; a photoelectric conversion element that converts the received incident light into an electrical signal; A waveguide section that is provided between the wave-front control element and the photoelectric conversion element in the stacking direction, has a plurality of refractive indexes different from each other, and guides the incident light from the wave-front control element to the photoelectric conversion element; A light detection device comprising:

[0250] [Item 2] The wavefront control element has a metasurface optical element. Item 2. The optical detection device according to item 1.

[0251] [Item 3] The metasurface optical element outputs at least a first light component and a second light component in the incident light in directions different from each other, the photoelectric conversion element includes a first photopixel intended to receive the first light component and a second photopixel intended to receive the second light component; the plurality of refractive regions include a first refractive region and a second refractive region having a lower refractive index than the first refractive region; the waveguide portion has a plurality of unit structures each including the first refraction region and the second refraction region, Each unit structure is assigned to the first photopixel and the second photopixel that are adjacent to each other. Item 3. The optical detection device according to item 2.

[0252] [Item 4] Each unit structure has a first light guiding region intended to emit the first light component from the metasurface optical element toward the first optical pixel, and a second light guiding region intended to emit the second light component from the metasurface optical element toward the second optical pixel, Each of the first light guiding region and the second light guiding region includes the first refraction region and a second refraction region surrounding the first refraction region in a planar direction perpendicular to the stacking direction, and the second refraction region is located between the first refraction regions of the first light guiding region and the second light guiding region that are adjacent to each other. Item 4. The optical detection device according to item 3.

[0253] [Item 5] The first refraction region of the first light guiding region and the first refraction region of the second light guiding region have asymmetric planar shapes in the planar direction. 5. The optical detection device according to item 4.

[0254] [Item 6] Each unit structure has the first light guiding region and the second light guiding region positioned adjacent to each other in the planar direction perpendicular to the stacking direction, Each of the first light guiding region and the second light guiding region includes the first refraction region and the second refraction region that partially surrounds the first refraction region in the planar direction, and the second refraction region is partially located between the first refraction regions of the first light guiding region and the second light guiding region that are adjacent to each other. 6. The photodetector according to any one of items 3 to 5.

[0255] [Item 7] The first refraction region of the first light guiding region and the first refraction region of the second light guiding region have asymmetric planar shapes in the planar direction. Item 7. The optical detection device according to item 6.

[0256] [Item 8] One or more of the refractive regions among the plurality of refractive regions changes in shape in the stacking direction in a cross section along the stacking direction. 8. The photodetector according to any one of items 3 to 7.

[0257] [Item 9] The metasurface optical element outputs at least a first light component and a second light component in the incident light in directions different from each other, the photoelectric conversion element includes a first photopixel intended to receive the first light component and a second photopixel intended to receive the second light component; the waveguide portion includes a plurality of unit structures each assigned to the first pixel and the second pixel adjacent to each other; in a planar direction perpendicular to the stacking direction, central positions of at least a portion of the plurality of unit feature portions are offset from central positions of the first light pixel and the second pixel to which they are assigned, in accordance with image heights of the first light pixel and the second pixel to which they are assigned. 9. The photodetector according to any one of items 2 to 8.

[0258] [Item 10] an offset amount of each of the central positions of the plurality of unit feature portions from the central positions of the first light pixel and the second pixel to which the unit feature portions are assigned continuously changes according to an image height of the first light pixel and the second pixel to which the unit feature portions are assigned. 10. The optical detection device according to item 9.

[0259] [Item 11] an offset amount of each of the central positions of the plurality of unit feature portions from central positions of the first light pixel and the second pixel to which the unit feature portions are assigned varies discretely in accordance with an image height of the first light pixel and the second pixel to which the unit feature portions are assigned. Item 11. The optical detection device according to item 9 or 10.

[0260] [Item 12] an on-chip lens that outputs the incident light toward the wave-front control element; 12. The photodetector according to any one of items 2 to 11.

[0261] [Item 13] A polarizer is provided between the wave-front control element and the photoelectric conversion element. 13. The photodetector according to any one of items 2 to 12.

[0262] [Item 14] metal wiring provided between the wave-front control element and the photoelectric conversion element; 14. The photodetector according to any one of items 2 to 13.

[0263] [Item 15] A wavelength selection filter that selectively transmits light of a specific wavelength range from the incident light. 15. The photodetector according to any one of items 2 to 14.

[0264] [Item 16] The photoelectric conversion element outputs an electrical signal as an image signal. 16. The photodetector according to any one of items 2 to 15.

[0265] [Item 17] The metasurface optical element outputs at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in different directions from each other, The photoelectric conversion element includes a first photopixel intended to receive the first wavelength range component and a second photopixel intended to receive the second wavelength range component. Item 17. The optical detection device according to item 16.

[0266] [Item 18] The metasurface optical element outputs at least a first polarized light in the incident light and a second polarized light having a vibration direction different from that of the first polarized light in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive the first polarized light and a second photopixel intended to receive the second polarized light, Item 18. The optical detection device according to item 16 or 17.

[0267] [Item 19] The photoelectric conversion element outputs an electrical signal as a sensing signal. 19. The photodetector according to any one of items 2 to 18.

[0268] [Item 20] The metasurface optical element outputs at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in different directions from each other, The photoelectric conversion element includes a first photopixel intended to receive the first wavelength range component and a second photopixel intended to receive the second wavelength range component. 20. The optical detection device according to item 19.

[0269] [Item 21] the incident light is light from an object, The photoelectric conversion element outputs an electrical signal as a distance image signal including depth information of the object. 21. The photodetector according to any one of items 2 to 20.

[0270] [Item 22] The distance image signal includes the depth information based on a ToF method. 22. The optical detection device according to item 21. [Explanation of symbols]

[0271] 1 image sensor, 1A spectral imaging device, 1B polarization imaging device, 1C spectral sensing device, 1D sensing device, 10 light transmission control section, 11 photoelectric conversion element, 20 wavefront control element, 21 wave guide section, 22 aperture structure section, 31 first refraction region, 31a slit region, 32 second refraction region, 32a boundary region, 32b boundary protrusion region, 40 metasurface optical element, 41 meta atom, 42 structure peripheral section, 50 on-chip lens, 55 polarizer, 55n unit polarizer, 56 wire grid polarizer, 56-1 first wire grid polarizer region, 56-2 second wire grid polarizer region, 57 photonic crystal polarizer, 57-1 first photonic crystal polarizer region, 57-2 second photonic crystal polarizer region, 60 metal wiring, 63 wavelength selection filter, Cm aperture center, Cp Pixel center, Cs Spot center, Cw 2 pixel center, L Incident light, L1 First light component, L2 Second light component, L3 Third light component, Lp1 First polarization, Lp2 Second polarization, Lv1 First shooting light component, Lv2 Second shooting light component, Lv3 Third shooting light component, La Frontal incident light, Lb Inclined incident light, OP Optical system, OS Offset amount, Pm Aperture center point, Pu Unit pixel group, Pw 2 pixel center point, PX Light receiving pixel, PX1 First light pixel, PX2 Second light pixel, PX3 Third light pixel, R1 First light guiding area, R2 Second light guiding area, Rb Robust range, Sp Light receiving spot, θ Incident angle

Claims

1. A wavefront control element for controlling a wavefront of incident light; A photoelectric conversion element that converts the received incident light into an electrical signal; a waveguide section provided between the wave-front control element and the photoelectric conversion element in the stacking direction, the waveguide section having a plurality of refractive indexes different from each other, and guiding the incident light from the wave-front control element to the photoelectric conversion element; A light detection device comprising:

2. The wavefront control element has a metasurface optical element.

2. The optical detection device according to claim 1.

3. The metasurface optical element outputs at least a first light component and a second light component in the incident light in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive a first light component and a second photopixel intended to receive a second light component; The plurality of refractive regions includes a first refractive region and a second refractive region having a lower refractive index than the first refractive region; the waveguide portion has a plurality of unit structures each including a first refraction region and a second refraction region; Each unit structure is assigned to a first light pixel and a second light pixel that are adjacent to each other.

3. The optical detection device according to claim 2.

4. Each unit structure has a first light guiding region intended to emit a first light component from the metasurface optical element toward a first optical pixel, and a second light guiding region intended to emit a second light component from the metasurface optical element toward a second optical pixel; Each of the first light guiding region and the second light guiding region includes a first refraction region and a second refraction region surrounding the first refraction region in a planar direction perpendicular to the stacking direction, and the second refraction region is located between the first refraction regions of the first light guiding region and the second light guiding region located adjacent to each other.

4. The optical detection device according to claim 3.

5. The first refraction region of the first light guiding region and the first refraction region of the second light guiding region have asymmetric planar shapes in a planar direction; 5. The optical detection device according to claim 4.

6. Each unit structure has a first light guiding region and a second light guiding region positioned adjacent to each other in a planar direction perpendicular to the stacking direction, Each of the first light guiding region and the second light guiding region includes a first refractive region and a second refractive region that partially surrounds the first refractive region in a planar direction, and the second refractive region is partially located between the first refractive regions of the first light guiding region and the second light guiding region that are adjacent to each other.

4. The optical detection device according to claim 3.

7. The first refraction region of the first light guiding region and the first refraction region of the second light guiding region have asymmetric planar shapes in a planar direction; 7. The optical detection device according to claim 6.

8. One or more of the refractive regions among the plurality of refractive regions changes in shape in the stacking direction in a cross section along the stacking direction.

4. The optical detection device according to claim 3.

9. The metasurface optical element outputs at least a first light component and a second light component in the incident light in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive a first light component and a second photopixel intended to receive a second light component; the waveguide portion has a plurality of unit structures each assigned to a first light pixel and a second light pixel adjacent to each other; in a planar direction perpendicular to the stacking direction, central positions of at least a portion of the plurality of unit feature portions are offset from central positions of the first light pixel and the second pixel to be assigned in accordance with image heights of the first light pixel and the second pixel to be assigned; 3. The optical detection device according to claim 2.

10. an offset amount of each of the central positions of the plurality of unit feature portions from the central positions of the first light pixel and the second pixel to which the unit feature portions are assigned continuously changes in accordance with an image height of the first light pixel and the second pixel to which the unit feature portions are assigned.

10. The optical detection device according to claim 9.

11. an offset amount of each of the central positions of the plurality of unit feature portions from the central positions of the first light pixel and the second pixel to which the unit feature portions are assigned varies discretely in accordance with an image height of the first light pixel and the second pixel to which the unit feature portions are assigned.

10. The optical detection device according to claim 9.

12. An on-chip lens that outputs incident light toward a wavefront control element.

3. The optical detection device according to claim 2.

13. A polarizer is provided between the wave-front control element and the photoelectric conversion element.

3. The optical detection device according to claim 2.

14. Metal wiring is provided between the wave-front control element and the photoelectric conversion element.

3. The optical detection device according to claim 2.

15. A wavelength selection filter is provided to selectively transmit light of a specific wavelength range among the incident light.

3. The optical detection device according to claim 2.

16. The photoelectric conversion element outputs an electrical signal as an image signal.

3. The optical detection device according to claim 2.

17. The metasurface optical element outputs at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive a first wavelength range component and a second photopixel intended to receive a second wavelength range component.

17. The optical detection device of claim 16.

18. The metasurface optical element outputs at least a first polarized light in the incident light and a second polarized light having a vibration direction different from that of the first polarized light in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive light of a first polarization and a second photopixel intended to receive light of a second polarization; 17. The optical detection device of claim 16.

19. The photoelectric conversion element outputs an electrical signal as a sensing signal.

3. The optical detection device according to claim 2.

20. The metasurface optical element outputs at least a first wavelength range component in the incident light and a second wavelength range component having a wavelength range at least partially different from the first wavelength range component in directions different from each other, The photoelectric conversion element includes a first photopixel intended to receive a first wavelength range component and a second photopixel intended to receive a second wavelength range component.

20. The optical detection device of claim 19.

21. Incident light is the light coming from the object. The photoelectric conversion element outputs an electrical signal as a distance image signal including depth information of the object.

3. The optical detection device according to claim 2.

22. The distance image signal includes depth information based on the ToF method.

22. The optical detection device of claim 21.

Images