Optical device, optical detection system and manufacturing method thereof

Abstract

The optical device comprises: a first substrate having a first surface; a second substrate having a second surface at least partially opposed to the first surface; at least one optical waveguide extending along the first direction between the first substrate and the second substrate; and a plurality of elastic spacers arranged on at least one of the first surface and the second surface, including a first portion and a second portion. The first portion of the plurality of elastic spacers is at least one elastic spacer located between the first substrate and the second substrate and in a region where the first substrate and the second substrate overlap when viewed from a direction perpendicular to the first surface. The second portion of the plurality of elastic spacers is at least one elastic spacer located in a region where the first substrate and the second substrate do not overlap when viewed from a direction perpendicular to the first surface.

Description

Technical Field

[0001] The invention relates to an optical device, an optical detection system and a manufacturing method thereof. Background Art

[0002] Conventionally, various devices capable of scanning a space with light have been proposed.

[0003] Patent Document 1 discloses a structure in which scanning with passing light can be performed using a drive device that rotates a mirror.

[0004] Patent document 2 discloses an optical phased array having multiple nanophotonic antenna elements arranged in two dimensions. Each antenna element is optically coupled to a variable optical delay line (i.e., a phase shifter). In this optical phased array, a coherent light beam is guided to each antenna element through a waveguide, and the phase of the light beam is shifted by the phase shifter. As a result, the amplitude distribution of the far-field radiation pattern can be changed.

[0005] Patent document 3 discloses an optical deflection element comprising: an optical waveguide having an optical waveguide layer for guiding light inside and a first distributed Bragg mirror formed on the upper and lower surfaces of the optical waveguide layer; a light incident port for allowing light to be incident into the optical waveguide; and a light emission port formed on the surface of the optical waveguide in order to emit light that is incident from the light incident port and guided in the optical waveguide.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2013 / 168266

[0009] Patent Document 2: Japanese Patent Application No. 2016-508235

[0010] Patent Document 3: Japanese Patent Application Publication No. 2013-16591 Summary of the invention

[0011] Problems to be solved by the invention

[0012] An object of the present invention is to provide a new optical device having an optical waveguide with high dimensional accuracy.

[0013] Means used to solve problems

[0014] An optical device according to a technical solution of the present invention comprises: a first substrate having a first surface extending along a first direction and a second direction intersecting the first direction; a second substrate having a second surface at least partially opposed to the first surface; at least one optical waveguide extending along the first direction between the first substrate and the second substrate; and a plurality of elastic spacers arranged on at least one of the first surface and the second surface, including a first portion and a second portion. The second surface has an area different from that of the first surface. The first portion of the plurality of elastic spacers is at least one elastic spacer located between the first substrate and the second substrate and in a region where the first substrate and the second substrate overlap when viewed from a direction perpendicular to the first surface. The second portion of the plurality of elastic spacers is at least one elastic spacer located in a region where the first substrate and the second substrate do not overlap when viewed from a direction perpendicular to the first surface.

[0015] The comprehensive or specific aspects of the present invention may also be implemented through an apparatus, a system, a method, or any combination thereof.

[0016] Effects of the Invention

[0017] According to one aspect of the present invention, it is possible to realize an optical device including an optical waveguide having high dimensional accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view schematically showing the structure of the optical scanning device.

[0019] Figure 2 This is a diagram schematically showing an example of the cross-sectional structure of a waveguide element and propagating light.

[0020] Figure 3A This is a diagram showing a cross section of a waveguide array that emits light in a direction perpendicular to the emission surface of the waveguide array.

[0021] Figure 3B This is a diagram showing a cross section of a waveguide array that emits light in a direction different from a direction perpendicular to an emission surface of the waveguide array.

[0022] Figure 4 It is a stereoscopic diagram schematically showing a waveguide array in a three-dimensional space.

[0023] Figure 5 This is a schematic diagram of the waveguide array and phase shifter array viewed from the normal direction (Z direction) of the light exit surface.

[0024] Figure 6 This is a diagram schematically showing an example of a lower structure of an optical device when viewed from the Z direction.

[0025] Fig. 7A Yes means Figure 6 The figure shows the cross section along line AA.

[0026] Figure 7B Yes means Figure 6 The BB line cross section is shown.

[0027] Figure 7C Yes means Figure 6 The CC line cross section is shown.

[0028] Fig. 8A It indicates that it fits Fig. 7A A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0029] Figure 8B It indicates that it fits Figure 7B A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0030] Figure 8C It indicates that it fits Figure 7C A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0031] Fig. 9 This is a diagram schematically showing an example of the lower structure of the optical device according to the present embodiment when viewed from the Z direction.

[0032] Fig. 10A Yes means Fig. 9 The figure shows the cross section along line AA.

[0033] Fig. 10B Yes means Fig. 9 The BB line cross section is shown.

[0034] Fig. 10C Yes means Fig. 9 The CC line cross section is shown.

[0035] Fig.11A It indicates that it fits Fig. 10A A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0036] Fig. 11B It indicates that it fits Fig. 10B A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0037] Fig. 11C It indicates that it fits Fig. 10C A diagram showing an example of an optical device with a lower structure and an upper structure shown.

[0038] Fig. 12AIt is a schematic representation of the fit Fig.11A A diagram showing an example of an optical device in which unnecessary portions of a lower structure and an upper structure are cut off.

[0039] Fig. 12B It is a schematic representation of the fit Fig. 11B A diagram showing an example of an optical device in which unnecessary portions of a lower structure and an upper structure are cut off.

[0040] Fig.13 It is a diagram showing the structure of an optical scanning device according to a modified example.

[0041] Fig.14 FIG. 1 is a diagram schematically showing emission of light from an optical device.

[0042] Fig.15 This is a flow chart showing the manufacturing process of an optical device.

[0043] Fig.16 This is a diagram showing a configuration example of an optical scanning device in which components such as a spectrometer, a waveguide array, a phase shifter array, and a light source are integrated on a circuit board.

[0044] Fig.17 This is a schematic diagram showing a state in which a light beam such as a laser is irradiated from an optical scanning device toward a distant place to perform two-dimensional scanning.

[0045] Fig.18 This is a block diagram showing a configuration example of a LiDAR system capable of generating a ranging image. DETAILED DESCRIPTION

[0046] In this specification, "at least one of the refractive index, thickness and wavelength" means at least one selected from the group consisting of the refractive index of the optical waveguide layer, the thickness of the optical waveguide layer and the wavelength input to the optical waveguide layer. In order to change the emission direction of light, any one of the refractive index, thickness and wavelength may be controlled individually. Alternatively, any two or all of these three may be controlled to change the emission direction of light. In the following embodiments, the wavelength of light input to the optical waveguide layer may be controlled instead of or in addition to the control of the refractive index or thickness.

[0047] The above basic principle can be applied not only to the purpose of emitting light, but also to the purpose of receiving optical signals. By changing at least one of the refractive index, thickness and wavelength, the direction of the light that can be received can be changed one-dimensionally. Furthermore, if the phase difference of light is changed by multiple phase shifters respectively connected to multiple waveguide elements arranged in one direction, the direction of the light that can be received can be changed two-dimensionally.

[0048] The optical scanning device and the optical receiving device of the embodiment of the present invention can be used as antennas of optical detection systems such as LiDAR (Light Detection and Ranging) systems. Compared with radar systems that use radio waves such as millimeter waves, LiDAR systems use short-wavelength electromagnetic waves (visible light, infrared light, or ultraviolet light), so they can detect the distance distribution of objects with higher resolution. Such LiDAR systems are installed in automobiles, UAVs, and other vehicles. i The invention can be used as one of the collision avoidance technologies for mobile objects such as alVehicle (so-called drone) and AGV (Automated Guided Vehicle). In this specification, the optical scanning device and the optical receiving device are sometimes referred to as "optical devices". In addition, the devices used in the optical scanning device or the optical receiving device are sometimes referred to as "optical devices".

[0049] <Configuration Example of Optical Scanning Device>

[0050] The structure of an optical scanning device that performs two-dimensional scanning is described below as an example. However, there are cases where the detailed descriptions required are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of substantially the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the inventors provide the drawings and the following descriptions in order to enable those skilled in the art to fully understand the present invention, and they are not intended to limit the subject matter described in the claims. In the following description, the same reference numerals are given to the same or similar components.

[0051] In the present invention, "light" refers to electromagnetic waves including not only visible light (wavelength of about 400nm to about 700nm), but also ultraviolet light (wavelength of about 10nm to about 400nm) and infrared light (wavelength of about 700nm to about 1mm). In this specification, ultraviolet light may be referred to as "ultraviolet light" and infrared light may be referred to as "infrared light".

[0052] In the present invention, "scanning" based on light means changing the direction of light. "One-dimensional scanning" means changing the direction of light linearly along a direction intersecting the direction. "Two-dimensional scanning" means changing the direction of light two-dimensionally along a plane intersecting the direction.

[0053] Figure 1 1 is a perspective view schematically showing the structure of an optical scanning device 100 according to an embodiment. The optical scanning device 100 includes a waveguide array including a plurality of waveguide elements 10. The plurality of waveguide elements 10 each have a first direction ( Figure 1The plurality of waveguide elements 10 are shaped to extend in a second direction ( Figure 1 The plurality of waveguide elements 10 are regularly arranged in the Y direction (in the X direction). The plurality of waveguide elements 10 propagate light in the first direction while emitting light in a third direction D3 intersecting an imaginary plane parallel to the first and second directions. The first direction (X direction) and the second direction (Y direction) are orthogonal, but the two directions may not be orthogonal. The plurality of waveguide elements 10 are arranged at equal intervals in the Y direction, but they do not necessarily need to be arranged at equal intervals.

[0054] In addition, the orientation of the structures shown in the drawings of the present application is set for easy understanding of the description, and is not intended to limit the orientation of the structures in the implementation of reality. In addition, the shape and size of the entire or a part of the structures shown in the drawings do not limit the shape and size of reality.

[0055] The plurality of waveguide elements 10 each include a first mirror 30 and a second mirror 40 (hereinafter, each will be simply referred to as a "mirror") facing each other, and an optical waveguide layer 20 located between the mirrors 30 and 40. The mirrors 30 and 40 each include a reflection surface intersecting with the third direction D3 at an interface with the optical waveguide layer 20. The mirrors 30 and 40 and the optical waveguide layer 20 have a shape extending in the first direction (X direction).

[0056] In addition, as described later, the plurality of first mirrors 30 of the plurality of waveguide elements 10 may be a plurality of parts of a mirror constructed integrally. In addition, the plurality of second mirrors 40 of the plurality of waveguide elements 10 may be a plurality of parts of a mirror constructed integrally. Furthermore, the plurality of optical waveguide layers 20 of the plurality of waveguide elements 10 may be a plurality of parts of an optical waveguide layer constructed integrally. A plurality of waveguides can be formed by at least (1) each first mirror 30 being constructed separately from other first mirrors 30, or (2) each second mirror 40 being constructed separately from other second mirrors 40, or (3) each optical waveguide layer 20 being constructed separately from other optical waveguide layers 20. "Separately constructed" includes not only physically providing a space, but also separating by sandwiching materials with different refractive indices.

[0057] The reflection surface of the first mirror 30 and the reflection surface of the second mirror 40 are substantially parallel to each other. Of the two mirrors 30 and 40, at least the first mirror 30 has a characteristic of transmitting a part of the light propagating in the optical waveguide layer 20. In other words, the first mirror 30 has a higher light transmittance for the light than the second mirror 40. Therefore, a part of the light propagating in the optical waveguide layer 20 is emitted to the outside from the first mirror 30. Such mirrors 30 and 40 may be, for example, multilayer film mirrors formed of a dielectric multilayer film (sometimes referred to as a "multilayer reflective film").

[0058] By controlling the phase of light input to each waveguide element 10 and thereby synchronously changing the refractive index or thickness of the optical waveguide layer 20 of these waveguide elements 10 or the wavelength of light input to the optical waveguide layer 20 , two-dimensional scanning by light can be achieved.

[0059] In order to realize such two-dimensional scanning, the inventors of the present invention analyzed the operating principle of the waveguide element 10. Based on the results, the inventors succeeded in realizing two-dimensional scanning using light by synchronously driving a plurality of waveguide elements 10.

[0060] like Figure 1 As shown, if light is input to each waveguide element 10, the light is emitted from the emission surface of each waveguide element 10. The emission surface is located on the opposite side of the reflection surface of the first mirror 30. The direction D3 of the emitted light depends on the refractive index and thickness of the optical waveguide layer and the wavelength of the light. At least one of the refractive index, thickness and wavelength of each optical waveguide layer is synchronously controlled so that the light emitted from each waveguide element 10 is roughly in the same direction. In this way, the component of the X direction of the wave number vector of the light emitted from the plurality of waveguide elements 10 can be changed. In other words, the direction D3 of the emitted light can be changed along Figure 1 The direction 101 shown changes.

[0061] Furthermore, since the light emitted from the plurality of waveguide elements 10 is directed in the same direction, the emitted light interferes with each other. By controlling the phase of the light emitted from each waveguide element 10, the direction in which the light mutually reinforces each other through interference can be changed. For example, when a plurality of waveguide elements 10 of the same size are arranged at equal intervals in the Y direction, light having a phase difference of a certain amount is input to the plurality of waveguide elements 10. By changing this phase difference, the component in the Y direction of the wave number vector of the emitted light can be changed. In other words, by changing the phase difference of the light introduced into the plurality of waveguide elements 10 respectively, the direction D3 in which the light mutually reinforces each other through interference can be made to be along Figure 1 The direction 102 shown changes. Thus, two-dimensional scanning based on light can be achieved.

[0062] The operating principle of the optical scanning device 100 will be described below.

[0063] <Operation Principle of Waveguide Components>

[0064] Figure 2 Schematic diagram of the cross-sectional structure of a waveguide element 10 and an example of propagating light. Figure 2 In Figure 1The direction perpendicular to the X and Y directions is set as the Z direction, and the cross section parallel to the XZ plane of the waveguide element 10 is schematically shown. In the waveguide element 10, a pair of mirrors 30 and 40 are arranged so as to sandwich the optical waveguide layer 20. The light 22 introduced from one end of the optical waveguide layer 20 in the X direction is set on the upper surface ( Figure 2 The first mirror 30 disposed on the upper surface of the Figure 2 The light is repeatedly reflected by the second mirror 40 (the lower surface in the middle) while propagating in the optical waveguide layer 20. The light transmittance of the first mirror 30 is higher than that of the second mirror 40. Therefore, part of the light can be output mainly from the first mirror 30.

[0065] In a conventional waveguide such as an optical fiber, light propagates along the waveguide while being repeatedly totally reflected. In contrast, in the waveguide element 10 of the present invention, light propagates while being repeatedly reflected by the mirrors 30 and 40 disposed above and below the optical waveguide layer 20. Therefore, there is no restriction on the propagation angle of light. Here, the propagation angle of light refers to the incident angle directed to the interface between the mirror 30 or the mirror 40 and the optical waveguide layer 20. Light incident at an angle closer to perpendicular to the mirror 30 or the mirror 40 can also propagate. That is, light incident on the interface at an angle smaller than the critical angle of total reflection can also propagate. Therefore, the group velocity of light in the propagation direction of light is greatly reduced compared to the speed of light in free space. As a result, the waveguide element 10 has the following properties: the propagation conditions of light vary greatly with changes in the wavelength of light, the thickness of the optical waveguide layer 20, and the refractive index of the optical waveguide layer 20. Such a waveguide is called a "reflection waveguide" or a "slow light waveguide".

[0066] The emission angle θ of light emitted from the waveguide element 10 into the air is expressed by the following equation (1).

[0067] [Formula 1]

[0068]

[0069] According to equation (1), by changing the wavelength λ of the light in the air and the refractive index n of the optical waveguide layer 20, w and the thickness d of the optical waveguide layer 20 , the emission direction of light can be changed.

[0070] For example, in n w =2, d = 387nm, λ = 1550nm, m = 1, the emission angle is 0°. If the refractive index is changed from this state to n w= 2.2, the emission angle changes to about 66°. On the other hand, if the refractive index is not changed but the thickness is changed to d = 420nm, the emission angle changes to about 51°. If the wavelength is changed to λ = 1500nm without changing the refractive index and the thickness, the emission angle changes to about 30°. w By changing either the thickness d of the optical waveguide layer 20 or the thickness d of the optical waveguide layer 20 , the emission direction of light can be greatly changed.

[0071] Therefore, the optical scanning device 100 controls the wavelength λ of the light input to the optical waveguide layer 20, the refractive index n of the optical waveguide layer 20, and the wavelength λ of the light input to the optical waveguide layer 20. w and at least one of the thickness d of the optical waveguide layer 20 to control the emission direction of the light. The wavelength λ of the light may also remain constant without changing during the operation. In this case, light scanning can be achieved with a simpler structure. The wavelength λ is not particularly limited. For example, the wavelength λ may be included in the wavelength range of 400nm to 1100nm (from visible light to near-infrared light) that can obtain high detection sensitivity by a conventional photodetector or image sensor that detects light by absorbing light with silicon (Si). In another example, the wavelength λ may be included in the wavelength range of near-infrared light of 1260nm to 1625nm where the transmission loss in the optical fiber or Si waveguide is relatively small. In addition, these wavelength ranges are examples. The wavelength range of the light used is not limited to the wavelength range of visible light or infrared light, for example, it may also be the wavelength range of ultraviolet light.

[0072] In order to change the direction of the emitted light, the optical scanning device 100 may include a first adjustment element that changes at least one of the refractive index, thickness, and wavelength of the optical waveguide layer 20 in each waveguide element 10 .

[0073] As described above, when the waveguide element 10 is used, the refractive index n of the optical waveguide layer 20 is set to w By changing at least one of the thickness d and the wavelength λ, the emission direction of the light can be greatly changed. Thus, the emission angle of the light emitted from the mirror 30 can be changed in the direction along the waveguide element 10. By using at least one waveguide element 10, such one-dimensional scanning can be achieved.

[0074] The optical waveguide layer 20 may include a liquid crystal material or an electro-optical material to adjust the refractive index of at least a portion of the optical waveguide layer 20. The optical waveguide layer 20 may be sandwiched by a pair of electrodes. The refractive index of the optical waveguide layer 20 may be changed by applying a voltage to the pair of electrodes.

[0075] In order to adjust the thickness of the optical waveguide layer 20, for example, at least one actuator may be connected to at least one of the first mirror 30 and the second mirror 40. By changing the distance between the first mirror 30 and the second mirror 40 by the at least one actuator, the thickness of the optical waveguide layer 20 can be changed. If the optical waveguide layer 20 is formed of a liquid, the thickness of the optical waveguide layer 20 can be easily changed.

[0076] <Operation principle of 2D scanning>

[0077] In a waveguide array in which a plurality of waveguide elements 10 are arranged in one direction, the emission direction of light changes due to interference of light emitted from each waveguide element 10. The emission direction of light can be changed by adjusting the phase of light supplied to each waveguide element 10. The principle is described below.

[0078] Figure 3A is a diagram showing a cross section of a waveguide array that emits light in a direction perpendicular to the emission surface of the waveguide array. Figure 3A The phase shift amount of the light propagating in each waveguide element 10 is also described. Here, the phase shift amount is a value based on the phase of the light propagating in the waveguide element 10 at the left end. The waveguide array includes a plurality of waveguide elements 10 arranged at equal intervals. Figure 3A In FIG. 1 , the dotted arc represents the wavefront of the light emitted from each waveguide element 10. The straight line represents the wavefront formed by the interference of the light. The arrow represents the direction of the light emitted from the waveguide array (i.e., the direction of the wave number vector). Figure 3A In the example of , the phases of the lights propagating in the optical waveguide layers 20 in the waveguide elements 10 are all the same. In this case, the lights are emitted in a direction (Z direction) perpendicular to both the arrangement direction (Y direction) of the waveguide elements 10 and the direction (X direction) in which the optical waveguide layers 20 extend.

[0079] Figure 3B : is a diagram showing a cross section of a waveguide array that emits light in a direction different from a direction perpendicular to the emission surface of the waveguide array. Figure 3B In the example shown, the phases of the light propagating in the optical waveguide layer 20 in the plurality of waveguide elements 10 differ by a certain amount (Δφ) in the arrangement direction. In this case, the light is emitted in a direction different from the Z direction. By changing this Δφ, the component of the light wave number vector in the Y direction can be changed. If the center-to-center distance between two adjacent waveguide elements 10 is denoted by p, the light emission angle α0 is expressed by the following equation (2).

[0080] [Formula 2]

[0081]

[0082] exist Figure 2In the example shown, the emission direction of the light is parallel to the XZ plane. That is, α0 = 0°. Figure 3A and Figure 3B In the example shown, the direction of the light emitted from the optical scanning device 100 is parallel to the YZ plane. That is, θ=0°. However, generally, the direction of the light emitted from the optical scanning device 100 is neither parallel to the XZ plane nor to the YZ plane. That is, θ≠0° and α0≠0°.

[0083] Figure 4 It is a stereoscopic diagram schematically showing a waveguide array in a three-dimensional space. Figure 4 The thick arrow shown indicates the direction of light emitted from the optical scanning device 100. θ is the angle between the emission direction of the light and the YZ plane. θ satisfies equation (1). α0 is the angle between the emission direction of the light and the XZ plane. α0 satisfies equation (2).

[0084] <Phase Control of Light Introduced into Waveguide Array>

[0085] In order to control the phase of light emitted from each waveguide element 10, for example, a phase shifter that changes the phase of light may be provided before the light is introduced into the waveguide element 10. The optical scanning device 100 includes a plurality of phase shifters connected to each of the plurality of waveguide elements 10, and a second adjustment element that adjusts the phase of light propagating in each phase shifter. Each phase shifter includes a waveguide that is directly connected to the optical waveguide layer 20 in a corresponding one of the plurality of waveguide elements 10 or via another waveguide. The second adjustment element changes the direction (i.e., the third direction D3) of light emitted from the plurality of waveguide elements 10 by changing the difference in the phase of light propagating from the plurality of phase shifters to the plurality of waveguide elements 10. In the following description, as with a waveguide array, a plurality of arranged phase shifters may be referred to as a "phase shifter array".

[0086] Figure 5 This is a schematic diagram of the waveguide array 10A and the phase shifter array 80A viewed from the normal direction (Z direction) of the light exit surface. Figure 5 In the example shown, all phase shifters 80 have the same propagation characteristics, and all waveguide elements 10 have the same propagation characteristics. The phase shifters 80 and the waveguide elements 10 may have the same length or different lengths. When the lengths of the phase shifters 80 are equal, for example, the phase shift amounts of each can be adjusted by a driving voltage. In addition, by making a structure that changes the lengths of the phase shifters 80 in equal steps, it is possible to impart phase shifts of equal steps by the same driving voltage. Furthermore, the optical scanning device 100 further includes a spectrometer 90 that branches light and supplies it to a plurality of phase shifters 80, a first driving circuit 110 that drives each waveguide element 10, and a second driving circuit 210 that drives each phase shifter 80. Figure 5The straight arrow in represents the input of light. By independently controlling the first drive circuit 110 and the second drive circuit 210 which are respectively provided, two-dimensional scanning can be realized. In this example, the first drive circuit 110 functions as an element of the first adjustment element, and the second drive circuit 210 functions as an element of the second adjustment element.

[0087] The first driving circuit 110 changes the angle of light emitted from the optical waveguide layer 20 by changing at least one of the refractive index and the thickness of the optical waveguide layer 20 in each waveguide element 10. The second driving circuit 210 changes the phase of light propagating inside the optical waveguide 20a by changing the refractive index of the optical waveguide 20a in each phase shifter 80. The spectrometer 90 may be composed of a waveguide in which light propagates by total reflection, or may be composed of a reflective waveguide similar to the waveguide element 10.

[0088] In addition, after controlling the phase of each light branched by the spectrometer 90, each light may be introduced into the phase shifter 80. In this phase control, for example, a simple phase control structure that is achieved by adjusting the length of the waveguide to the phase shifter 80 may be used. Alternatively, a phase shifter that has the same function as the phase shifter 80 and can be controlled by an electrical signal may be used. By such a method, for example, the phase may be adjusted before being introduced into the phase shifter 80 so that all the phase shifters 80 are supplied with light of equal phase. By such an adjustment, the control of each phase shifter 80 by the second drive circuit 210 can be simplified.

[0089] An optical device having the same structure as the optical scanning device 100 described above can also be used as an optical receiving device. Details of the operating principle and operating method of the optical device are disclosed in U.S. Patent Application Publication No. 2018 / 0224709. The entire disclosure of this document is cited in this specification.

[0090] <Fabrication of optical devices by bonding>

[0091] The optical device 100 can be manufactured, for example, by laminating an upper structure having a first mirror and a lower structure having a second mirror. In laminating, for example, a sealing member such as an ultraviolet curing resin or a thermosetting resin can be used. For optical scanning based on voltage application, the optical waveguide layer 20 can include a liquid crystal material, for example. In order to inject the liquid crystal material into the optical device 100, for example, vacuum sealing can be used. If the liquid crystal material is injected into the space surrounded by the above-mentioned sealing member, vacuum leakage can be prevented when the liquid crystal material is injected.

[0092] Figure 6 1 is a diagram schematically showing an example of the lower structure 100 a of the optical device 100 when viewed from the Z direction. 7A to 7CThey are respectively Figure 6 The diagrams show the cross section along the line AA, the cross section along the line BB, and the cross section along the line CC. 7A to 7C An example of a lower structure 100a and an upper structure 100b of the optical device 100 is schematically shown. 7A to 7C The downward arrow shown indicates the direction of fit.

[0093] After the lower structure 100a and the upper structure 100b are attached, Figure 6 The sealing port 79o shown is filled with liquid crystal material. Then, the sealing port 79o is sealed by the same member as the sealing member 79. The lower structure 100a includes a substrate 50a, an electrode 62a, a mirror 40, a dielectric layer 51, a plurality of optical waveguides 11, a plurality of partition walls 73 and a sealing member 79. The upper structure 100b includes a substrate 50b, an electrode 62b and a mirror 30. The details thereof will be described later.

[0094] FIG. 8A to FIG. 8C They are respectively 7A to 7C FIG. 1 is a diagram showing an example of an optical device 100 with a lower structure 100a and an upper structure 100b. FIG. 8A to FIG. 8C As shown, even if the lower structure 100a and the upper structure 100b are bonded in a parallel manner, there are actually cases where the substrate 50a and the substrate 50b are not parallel. This is because, when the upper structure 100b and the lower structure 100a are bonded, the part where the upper structure 100b and the lower structure 100a first contact becomes the fulcrum. For example, the part where the sealing component 79 contacts the electrode 62b, or the part where one of the multiple partition walls 73 contacts the mirror 30 will become the fulcrum. If the force acting on the upper structure 100b during bonding is uneven, the interval between the substrate 50a and the substrate 50b will be different in the part closer to the fulcrum and the part farther from the fulcrum. For example, in the part farther from the fulcrum, the interval between the substrate 50a and the substrate 50b will become larger than that in the part closer to the fulcrum. Therefore, there are cases where the substrate 50a and the substrate 50b are not parallel. In this case, the intensity of light emitted from the optical device 100 and the emission angle of light may deviate from the designed values.

[0095] Based on the above studies, the inventors of the present invention have conceived of optical devices described in the following items.

[0096] The optical device according to the first item comprises: a first substrate having a first surface extending along a first direction and a second direction intersecting the first direction; a second substrate having a second surface at least partially opposite to the first surface; at least one optical waveguide extending along the first direction between the first substrate and the second substrate; and a plurality of elastic spacers arranged on at least one of the first surface and the second surface, including a first portion and a second portion. The second surface has an area different from that of the first surface. The first portion of the plurality of elastic spacers is at least one elastic spacer located between the first substrate and the second substrate and in a region where the first substrate and the second substrate overlap when viewed from a direction perpendicular to the first surface. The second portion of the plurality of elastic spacers is at least one elastic spacer located in a region where the first substrate and the second substrate do not overlap when viewed from a direction perpendicular to the first surface.

[0097] In the optical device, the first part of the plurality of elastic spacers can make the interval between the first substrate and the second substrate uniform. As a result, the intensity of the emitted light and the accuracy of the emission angle can be greatly improved. Furthermore, the second part of the plurality of elastic spacers can protect the components arranged in the area where the first substrate and the second substrate do not overlap from external contact.

[0098] The optical device according to item 2 is the optical device according to item 1, further comprising a plurality of partition walls extending along the first direction. The plurality of partition walls are arranged in the second direction between the first substrate and the second substrate. The elastic modulus of each of the plurality of elastic spacers is smaller than the elastic modulus of each of the plurality of partition walls.

[0099] In this optical device, the interval between the first substrate and the second substrate becomes uniform as a whole due to the elastic spacer that acts like a spring and is compressed.

[0100] The optical device related to item 3 is the optical device related to item 2, wherein the plurality of partition walls are directly or indirectly clamped by the first substrate and the second substrate. Due to the clamping of the first substrate and the second substrate, the deformation rate of each of the plurality of elastic spacers in a direction perpendicular to the first surface is greater than the deformation rate of each of the plurality of partition walls in the perpendicular direction.

[0101] In this optical device, since the deformation rate of each spacer is larger than the deformation rate of each partition wall, the interval between the first substrate and the second substrate becomes uniform as a whole.

[0102] The optical device according to item 4 is the optical device according to any one of items 1 to 3, wherein each of the plurality of elastic spacers has a columnar shape.

[0103] In this optical device, the same effects as those of the optical devices according to the first to third items can be obtained.

[0104] The optical device related to item 5 In the optical device related to any one of items 1 to 4, the at least one optical waveguide comprises: a first portion arranged between the first substrate and the second substrate and in an area where the first substrate and the second substrate overlap; and a second portion arranged in an area where the first substrate and the second substrate do not overlap.

[0105] In this optical device, light can be input from the second portion to the first portion.

[0106] The optical device according to item 6 is the optical device according to item 5, wherein the at least one optical waveguide is a plurality of optical waveguides, and at least a portion of the second portions of the plurality of elastic spacers is located around the second portions of the plurality of optical waveguides.

[0107] In this optical device, the second portions of the plurality of optical waveguides can be protected from external contact by at least a portion of the second portions of the plurality of elastic spacers.

[0108] The optical device according to item 7 is the optical device according to item 5 or 6, wherein the at least one optical waveguide includes a portion located between two adjacent partition walls, and the first grating is provided in the portion.

[0109] In this optical device, light propagating through the optical waveguide can be coupled with high efficiency via the first grating.

[0110] The optical device according to item 8 is the optical device according to any one of items 5 to 7, wherein the at least one optical waveguide includes a second grating in the second portion.

[0111] In this optical device, light can be input from the outside into the optical waveguide via the second grating with high efficiency.

[0112] The optical device according to item 9 is an optical device according to any one of items 1 to 8, further comprising a sealing member for fixing the interval between the first substrate and the second substrate. The at least one optical waveguide has a structure in which at least one first optical waveguide is connected to at least one second optical waveguide, respectively. When viewed from a direction perpendicular to the first surface, the sealing member surrounds the at least one first optical waveguide.

[0113] In this optical device, one or more first optical waveguides can be sealed by the first substrate, the second substrate, and the sealing member.

[0114] The optical device according to item 10 is the optical device according to item 9, wherein each of the one or more first optical waveguides includes one or more dielectric members extending along the first direction, and a region between the first substrate and the second substrate and surrounded by the sealing member is filled with the same member as the one or more dielectric members.

[0115] In this optical device, by filling the space sealed by the first substrate, the second substrate, and the sealing member with the same member as one or more dielectric members, one or more first optical waveguides can be easily manufactured.

[0116] The optical device according to item 11 is the optical device according to any one of items 1 to 10, wherein each of the one or more first optical waveguides includes one or more dielectric members extending along the first direction. The optical device further includes two mirrors, the two mirrors being located between the first substrate and the one or more dielectric members, and between the second substrate and the one or more dielectric members, respectively.

[0117] In this optical device, each first optical waveguide functions as a reflective waveguide by means of two mirrors, thereby making it possible to emit light propagating through each first optical waveguide to the outside.

[0118] The optical device according to item 12 is the optical device according to item 11, wherein at least a part of the first portion of the plurality of elastic spacers is located outside a region sandwiched by the two mirrors.

[0119] In this optical device, even if particles are mixed outside the area sandwiched by two mirrors, the distance between the first substrate and the second substrate in the direction perpendicular to the first surface in this area is large, so the distance between the first substrate and the second substrate after bonding can be made uniform.

[0120] The optical device according to item 13 is an optical device according to any one of items 10 to 12, wherein the one or more first optical waveguides have a structure capable of adjusting the refractive index of the one or more dielectric members. By adjusting the refractive index of the one or more dielectric members, the direction of light emitted from the one or more first optical waveguides via the first substrate or the second substrate, or the incident direction of light taken into the one or more first optical waveguides via the first substrate or the second substrate changes.

[0121] In this optical device, it is possible to realize an optical scanning device capable of changing the emission direction of light or an optical receiving device capable of changing the reception direction of light.

[0122] The optical device according to item 14 is the optical device according to item 13, further comprising a pair of electrodes sandwiching the one or more dielectric components. The one or more dielectric components contain a liquid crystal material or an electro-optical material. The refractive index of the one or more dielectric components is adjusted by applying a voltage to the pair of electrodes.

[0123] In this optical device, the optical device according to item 13 can be realized by applying voltage.

[0124] The optical device according to item 15 is the optical device according to item 14, further comprising one or more phase shifters connected to the one or more first optical waveguides respectively directly or via other waveguides. By changing the phase difference of the light passing through the one or more phase shifters, the direction of the light emitted from the one or more first optical waveguides via the first substrate or the second substrate, or the incident direction of the light taken into the one or more first optical waveguides via the first substrate or the second substrate is changed.

[0125] This optical device can realize an optical scanning device capable of independently changing the emission direction of light in two directions by one or more phase shifters, or an optical receiving device capable of independently changing the reception direction of light in two directions.

[0126] The optical detection system related to item 16 comprises: an optical device related to any one of items 1 to 15; a photodetector that detects light emitted from the above-mentioned optical device and reflected from an object; and a signal processing circuit that generates distance distribution data based on the output of the above-mentioned photodetector.

[0127] In this light detection system, by measuring the time it takes for light reflected from an object to return, distance distribution data of the object can be obtained.

[0128] The manufacturing method of the optical device related to item 17 includes: a process of preparing a first substrate having a first surface and a second substrate having a second surface; a process of forming at least one optical waveguide extending in one direction on the first surface of the first substrate; a process of forming a plurality of elastic spacers on the first surface of the first substrate or the second surface of the second substrate; a process of fixing the first substrate and the second substrate so that the first surface of the first substrate and the second surface of the second substrate are opposite to each other in a manner that the plurality of elastic spacers are located around the at least one optical waveguide; and a process of cutting and removing a portion of the first substrate or the second substrate on which the plurality of elastic spacers are not provided to expose a portion of the plurality of elastic spacers.

[0129] The optical device according to the first item can be manufactured by this method of manufacturing an optical device.

[0130] The method for manufacturing an optical device according to item 18 is the method for manufacturing an optical device according to item 17, further comprising the step of forming a plurality of partition walls. The step of forming the at least one optical waveguide includes the step of providing one or more dielectric members between the plurality of partition walls, the step of providing the one or more dielectric members being performed later than the step of forming the plurality of partition walls.

[0131] In this method of manufacturing an optical device, one or more optical waveguides each having one or more dielectric members can be formed between the plurality of partition walls.

[0132] The method for manufacturing an optical device according to item 19 is the method for manufacturing an optical device according to item 17, further comprising the step of forming a plurality of partition walls. The step of forming the at least one optical waveguide further comprises the step of injecting one or more dielectric members containing a liquid crystal material between the plurality of partition walls, the step of injecting the one or more dielectric members containing a liquid crystal material being performed after the step of fixing the first substrate and the second substrate.

[0133] In this method of manufacturing an optical device, one or more optical waveguides each having one or more dielectric members containing a liquid crystal material can be formed between the plurality of partition walls.

[0134] Hereinafter, an optical device according to an exemplary embodiment of the present invention will be described.

[0135] (Implementation Method)

[0136] Fig. 9 It is a plan view schematically showing an example of a lower structure 100a of the optical device 100 according to the present embodiment. FIG. 10A to FIG. 10C They are respectively Fig. 9 The diagrams show the cross section along the line AA, the cross section along the line BB, and the cross section along the line CC.

[0137] The optical device 100 includes a first substrate 50a, a second substrate 50b, a plurality of partition walls 73, a plurality of first optical waveguides 10, a plurality of elastic spacers 77, a sealing member 79, and a plurality of second optical waveguides 11. The number of the first optical waveguides 10 is not limited, and may be one. The same is true for the second optical waveguide 11 and the elastic spacer 77. In the following description, the "first substrate 50a" and the "second substrate 50b" are referred to as "substrates 50a" and "substrates 50b", respectively, and the "first optical waveguide 10" and the "second optical waveguide 11" are referred to as "optical waveguides 10" and "optical waveguides 11", respectively.

[0138] The optical device 100 of the present embodiment includes a lower structure 100a and an upper structure 100b.

[0139] The lower structure 100a includes a substrate 50a, an electrode 62a, a mirror 40, a dielectric layer 51, a plurality of partition walls 73, a plurality of elastic spacers 77, a sealing member 79, and an optical waveguide 11. Fig. 10A As shown, the substrate 50a has a first surface 50as extending in the X direction and the Y direction. An electrode 62a is provided on the substrate 50a. A mirror 40 is provided on the electrode 62a. A dielectric layer 51 is provided on the mirror 40. A partition wall 73, an elastic spacer 77, a sealing member 79 and an optical waveguide 11 are provided on the dielectric layer 51.

[0140] The upper structure 100b includes a substrate 50b having a second surface 50bs, an electrode 62b, and a mirror 30. The second surface 50bs faces the first surface 50as of the substrate 50a. The second surface 50bs has substantially the same area as the first surface 50as. The electrode 62b is provided on the substrate 50b. The mirror 30 is provided on the electrode 62b.

[0141] The substrate 50a and the substrate 50b on the side from which light is emitted may be light-transmitting. Alternatively, both the substrate 50a and the substrate 50b may be light-transmitting. Similarly, the electrode 62a and the electrode 62b on the side from which light is emitted may be light-transmitting. Alternatively, both the electrode 62a and the electrode 62b may be light-transmitting. At least one of the electrode 62a and the electrode 62b may be formed of a transparent electrode, for example. Fig. 9 and FIG. 10A to FIG. 10C In the example shown, light is emitted from the optical waveguide 10 via the electrode 62 b and the substrate 50 b of the upper structure 100 b .

[0142] like Fig. 9 As shown, a plurality of partition walls 73 are located between the substrate 50a and the substrate 50b and are arranged in the Y direction. Each partition wall 73 extends along the X direction.

[0143] A plurality of optical waveguides 10 are defined between a plurality of partition walls 73. Each optical waveguide 10 includes a dielectric member 21 extending along the X direction. Figures 10A to 10C : represents the state before the material constituting the dielectric component 21 is injected. The dielectric component 21 includes, for example, a liquid crystal material or an electro-optical material. The optical waveguide 10 includes a mirror 30, a mirror 40, and the dielectric component 21. The dielectric component 21 is provided in a region surrounded by the mirrors 30, 40 and two adjacent partition walls 73. The optical waveguide 10 functions as the above-mentioned slow light waveguide. The mirror 40 is located between the substrate 50a and the dielectric component 21. The mirror 30 is located between the substrate 50b and the dielectric component 21. The dielectric component 21 constitutes Figure 2 The optical waveguide layer 20 is shown. Fig. 9 and FIG. 10A to FIG. 10CIn the example shown, a part of the dielectric layer 51 in the optical waveguide layer 20 is removed, and a part of the mirror 40 is exposed. The optical waveguide layer 20 is formed in a region sandwiched between the mirror 30 and the mirror 40 .

[0144] The refractive index of the dielectric member 21 is higher than the refractive index of the partition wall 73 and the dielectric layer 51. Therefore, the light propagating in the optical waveguide layer 20 does not leak to the partition wall 73 and the dielectric layer 51 directly thereunder. The light propagating in the optical waveguide layer 20 is totally reflected at the interface between the optical waveguide layer 20 and each partition wall 73 and at the interface between the optical waveguide layer 20 and the dielectric layer 51.

[0145] The pair of electrodes 62a and 62b directly or indirectly sandwich the dielectric member 21. "Directly sandwiched" means not sandwiched via other members. "Indirectly sandwiched" means sandwiched via other members. By applying a voltage to the pair of electrodes 62a and 62b, the refractive index of the dielectric member 21 is adjusted. As a result, the emission angle of light emitted from the optical waveguide 10 to the outside changes.

[0146] The optical waveguide 10 does not need to be a slow light waveguide. The optical waveguide 10 may be a waveguide that propagates light by total reflection, for example. In this waveguide, light is emitted to the outside from the end of the optical waveguide 10 without passing through the substrate 50a or the substrate 50b.

[0147] A plurality of elastic spacers 77 are disposed around the plurality of optical waveguides 10. Fig. 9 In the example shown, a plurality of columnar elastic spacers 77 are arranged two-dimensionally. This arrangement may be regular or periodic, or may be irregular. The diameter of the elastic spacer 77 in the XY plane may be, for example, not less than 10 μm and not more than 100 μm. Fig. 9 In the example shown, the elastic spacer 77 is located on both the inside and outside of the region surrounded by the sealing member 79. The elastic spacer 77 may be provided only on one of the inside and outside of the region. In this way, the elastic spacer 77 is located on at least one of the inside and outside of the region. A part of the elastic spacer 77 may be provided in the optical waveguide layer 20. The elastic spacer 77 may have a shape that is connected to one inside and / or outside of the region surrounded by the sealing member 79. This shape may be, for example, a straight line, a curved line, a wavy line, or a sawtooth line when viewed from the Z direction.

[0148] In the state before the lower structure 100a and the upper structure 100b are attached, the size of the elastic spacer 77 in the Z direction is larger than the sum of the sizes of the partition wall 73 and the mirror 30 in the Z direction. In addition, in this state, the size of the elastic spacer 77 in the Z direction is larger than the size of the sealing member 79 in the Z direction. Therefore, when the lower structure 100a and the upper structure 100b are attached, the electrode 62b of the upper structure 100b first contacts the elastic spacer 77 of the lower structure 100a. Therefore, the portion where the sealing member 79 contacts the electrode 62b or the portion where the partition wall 73 contacts the mirror 30 does not become a fulcrum.

[0149] In the elastic spacer 77, elastic deformation occurs. When a force is applied to an elastic body and strain occurs, the elastic modulus is defined by dividing the applied force by the strain generated. The elastic modulus of the elastic spacer 77 is smaller than the elastic modulus of the partition wall 73 and the mirror 30. That is, the elastic spacer 77 is more easily deformed than the partition wall 73 and the mirror 30. When the lower structure 100a and the upper structure 100b are attached, the elastic spacer 77 acts like a spring and is compressed. As a result, the upper surface of the partition wall 73 is in uniform contact with the reflecting surface of the mirror 30, and the interval between the substrate 50a and the substrate 50b becomes uniform as a whole. As a result, the substrate 50a and the substrate 50b become roughly parallel. At this time, through the clamping of the substrate 50a and the substrate 50b, the deformation rate of each elastic spacer in the Z direction is greater than the deformation rate of each partition wall in the Z direction.

[0150] The sealing member 79 fixes the interval between the substrate 50a and the substrate 50b. Fig. 9 As shown, when viewed from the Z direction, the sealing member 79 surrounds the plurality of optical waveguides 10 and the plurality of partition walls 73. The sealing member 79 is arranged in the Y direction so as to cross the optical waveguide 11. The upper surface of the sealing member 79 is parallel to the XY plane. The size of the sealing member 79 in the Z direction on the dielectric layer 51 is equal to or greater than the sum of the size of the partition wall 73 in the Z direction and the size of the mirror 30. The sealing member 79 can be formed of, for example, an ultraviolet curing resin or a thermosetting resin. As long as it is a member capable of maintaining the interval between the substrate 50a and the substrate 50b for a long period of time, the material of the sealing member 79 does not need to be an ultraviolet curing resin or a thermosetting resin.

[0151] The optical waveguide 11 is connected to the optical waveguide 10. Light is supplied from the optical waveguide 11 to the optical waveguide 10. Fig. 9 and FIG. 10A to FIG. 10CIn the example shown, the optical waveguide 11 is located on the dielectric layer 51. The dielectric layer 51 is located between the substrate 50a and the optical waveguide 11. By adjusting the size of the dielectric layer 51 in the Z direction, the light propagating in the optical waveguide 11 can be coupled with the optical waveguide 10 with high efficiency. The size of the dielectric layer 51 in the Z direction can be adjusted, for example, so that the optical waveguide 11 is located near the center of the optical waveguide layer 20 in the Z direction. The optical waveguide 11 is a waveguide that propagates light by total reflection. Therefore, the refractive index of the optical waveguide 11 is higher than the refractive index of the dielectric layer 51. In addition, the optical waveguide 11 may also be a slow light waveguide.

[0152] Each of the plurality of optical waveguides 11 includes a portion located between two adjacent partition walls among the plurality of partition walls 73. Figures 9 to 10C As shown, the plurality of optical waveguides 11 are provided with gratings 15 at the portions thereof. The propagation constant of the optical waveguide 11 is different from the propagation constant of the optical waveguide 10. The propagation constant of the optical waveguide 11 is shifted by the amount of the inverse lattice by the gratings 15. When the propagation constant of the optical waveguide 11 shifted by the amount of the inverse lattice is consistent with the propagation constant of the optical waveguide 10, the light propagating in the optical waveguide 11 is coupled to the optical waveguide 10 with high efficiency.

[0153] FIG. 11A to FIG. 11C They are schematically shown to fit FIG. 10A to FIG. 10C FIG. 1 is a diagram showing an example of an optical device 100 in a state where a lower structure 100a and an upper structure 100b are provided. FIG. 11A to FIG. 11C As shown in FIG. 1 , when substrate 50a and substrate 50b are bonded together, force is uniformly applied to the first surface 50as and the second surface 50bs facing each other via the elastic spacer 77. As a result, substrate 50a and substrate 50b become substantially parallel. Elastic spacer 77 is directly or indirectly clamped by substrate 50a and substrate 50b. FIG. 11A to FIG. 11C In the example shown, the elastic spacer 77 is directly sandwiched between the dielectric layer 51 of the lower structure 100a and the electrode 62b of the upper structure 100b. The dimension of the elastic spacer 77 in the Z direction is larger than the dimension of the partition wall 73 in the Z direction.

[0154] Fig. 12A and Fig. 12B They are schematically indicated Fig.11A and Fig. 11B FIG. 5 is a diagram showing an example of a substrate 50b and an electrode 62b being partially cut. By cutting, a portion of the periphery of the area surrounded by the sealing member 79 is removed. As a result, the second surface 50bs has an area different from that of the first surface 50as. Fig. 12A and Fig. 12BAs shown, the optical waveguide 11 has a portion that overlaps with the substrate 50a but does not overlap with the substrate 50b when viewed from the Z direction. The optical waveguide 11 may also include a grating 13 in the non-overlapping portion. For the same reason as the above, when light is input through the grating 13, the input light can be coupled with the optical waveguide 11 with higher efficiency. The optical waveguide 11 may include a portion that overlaps with the substrate 50b but does not overlap with the substrate 50a, or a portion that does not overlap with both the substrate 50a and the substrate 50b. In this way, the optical waveguide 11 may have a portion that does not overlap with at least one of the substrate 50a and the substrate 50b when viewed from a direction perpendicular to the surface of each substrate. In this case, a portion of the elastic spacer 77 is not sandwiched by the substrate 50a and the substrate 50b and remains on the dielectric layer 51. The dimension of the portion of the elastic spacer 77 in the Z direction is larger than the dimension of the remaining elastic spacer 77 in the Z direction. Since a portion of the elastic spacer 77 remains, the electrode 62 a or the electrode 62 b , the grating 13 , and the optical waveguide 11 can be protected from external contact.

[0155] The functions of the elastic spacer 77 are summarized as follows: The elastic spacer 77 plays a role in making the substrate 50a and the substrate 50b parallel when manufacturing the optical device 100. The elastic spacer 77 plays a role in protecting some components from external contact when using the optical device 100.

[0156] In the case where the dielectric component 21 is made of a liquid crystal material, the liquid crystal material is injected from the sealing port 79o after the lower structure 100a and the upper structure 100b are bonded together. The liquid crystal material may be injected from the sealing port 79o after a portion of at least one of the bonded structures is cut off. After the liquid crystal material is injected, the sealing port 79o is sealed with the same member as the sealing member 79. The sealed area is filled with the liquid crystal material as a whole. This area is located between the substrate 50a and the substrate 50b and surrounded by the sealing member 79. This area is filled with the same member as the dielectric component 21.

[0157] Hereinafter, examples of details of materials and dimensions of components used in manufacturing the optical device 100 will be described. Hereinafter, the dimension in the Z direction may be referred to as “thickness”.

[0158] First, examples of materials and dimensions of components of the lower structure 100 a will be described.

[0159] The substrate 50a may be formed of, for example, a SiO2 layer. The dimensions of the substrate 50a in the X direction and the Y direction may both be 15 mm. The thickness of the substrate 50a may be 0.7 mm, for example.

[0160] The electrode 62a may be formed of, for example, an ITO sputtered layer. The thickness of the electrode 62a may be, for example, 50 nm.

[0161] The mirror 40 may be a multilayer reflective film. The multilayer reflective film may be formed, for example, by alternately evaporating and laminating Nb2O5 layers and SiO2 layers. The Nb2O5 layer has a refractive index of n=2.282. The thickness of the Nb2O5 layer may be, for example, about 100 nm. The SiO2 layer has a refractive index of n=1.468. The thickness of the SiO2 layer may be, for example, about 200 nm. The mirror 40 may have, for example, 31 layers of Nb2O5 layers and 30 layers of SiO2 layers, a total of 61 layers. The thickness of the mirror 40 may be, for example, 9.1 μm.

[0162] The dielectric layer 51 can be formed of, for example, a SiO 2 vapor-deposited layer. The SiO 2 vapor-deposited layer has a refractive index of n = 1.468. The thickness of the SiO 2 vapor-deposited layer can be, for example, about 1.0 μm.

[0163] The optical waveguide 11 can be formed by, for example, a Nb2O5 vapor-deposited layer. The Nb2O5 vapor-deposited layer has a refractive index of n=2.282. The thickness of the Nb2O5 vapor-deposited layer can be, for example, about 300 nm. The grating 15 and the grating 13 can be formed in the optical waveguide 11. The grating 15 has, for example, a duty ratio of 1:1 and a pitch of 640 nm. The grating 13 has, for example, a duty ratio of 1:1 and a pitch of 680 nm. The grating 15 and the grating 13 can be formed by patterning based on photolithography. The size of the optical waveguide 11 in the Y direction can be, for example, 10 μm.

[0164] The partition wall 73 may be formed of a SiO2 vapor-deposited layer. The SiO2 vapor-deposited layer has a refractive index of n=1.468. The thickness of the SiO2 vapor-deposited layer may be, for example, 1.0 μm. The size of the partition wall 73 in the Y direction may be, for example, 50 μm.

[0165] In the optical waveguide layer 20, a part of the dielectric layer 51 may be removed by patterning based on photolithography, for example. The thickness of the optical waveguide layer 20 may be, for example, 2.0 μm. The size of the optical waveguide layer 20 in the Y direction may be, for example, 10 μm.

[0166] Next, the materials and dimensions of the components of the upper structure 100b will be described in detail.

[0167] The substrate 50b may be formed of, for example, a SiO2 layer. The dimensions of the substrate 50b in the X direction and the Y direction may be, for example, 8 mm and 20 mm, respectively, and the thickness of the substrate 50b may be, for example, 0.7 mm.

[0168] The electrode 62b may be formed of, for example, an ITO sputtered layer. The thickness of the electrode 62b may be, for example, 50 nm.

[0169] The mirror 30 may be a multilayer reflective film. The multilayer reflective film may be formed by alternately evaporating and stacking Nb2O5 layers and SiO2 layers. The Nb2O5 layer has a refractive index of n=2.282. The thickness of the Nb2O5 layer may be, for example, about 100 nm. The SiO2 layer has a refractive index of n=1.468. The thickness of the SiO2 layer may be, for example, about 200 nm. The mirror 30 may have, for example, 13 layers, including 7 Nb2O5 layers and 6 SiO2 layers. The thickness of the mirror 30 may be, for example, 1.9 μm.

[0170] Next, detailed examples of the materials and dimensions of the elastic spacer 77 and the sealing member 79 will be described.

[0171] For example, Micropearl EX-003 manufactured by Sekisui Chemical can be used as the elastic spacer 77. Before the lower structure 100a and the upper structure 100b are attached, the size of the elastic spacer 77 in the Z direction is, for example, 3.0 μm. This size of the elastic spacer 77 is larger than the sum of the thickness of the partition wall 73 and the thickness of the mirror 30. The thickness of the partition wall 73 can be, for example, 1 μm, and the thickness of the mirror 30 can be, for example, 1.9 μm.

[0172] For the dielectric member 21, for example, 5CB liquid crystal can be used.

[0173] For example, the ultraviolet curing adhesive 3026E made by ThreeBond can be used for the sealing member 79. For example, the ultraviolet curing adhesive 3026E made by ThreeBond can be used for the sealing member 79. 2 The sealing member 79 is cured by ultraviolet irradiation, thereby making it possible to bond the lower structure 100a and the upper structure 100b together. In this way, the optical device 100 of this embodiment can be obtained.

[0174] In addition, the substrate 50a and the substrate 50b may not be formed of SiO 2. The substrate 50a and the substrate 50b may be, for example, an inorganic substrate such as glass or sapphire, or a resin substrate such as acrylic or polycarbonate. These inorganic substrates and resin substrates are light-transmissive.

[0175] The transmittance of the mirror 30 that emits light is, for example, 99.9%, and the transmittance of the mirror 40 that does not emit light is, for example, 99.99%. This condition can be achieved by adjusting the number of layers of the multilayer reflective film. As a combination of two layers in the multilayer reflective film, for example, the refractive index of one layer is greater than 2, and the refractive index of the other layer is less than 2. If the difference between the two refractive indices is large, a high reflectivity can be obtained. The layer with a refractive index of greater than 2 can be made of, for example, SiN x 、AlN x 、TiO x 、ZrO x 、NbO xand TaO x The layer with a refractive index less than 2 can be formed, for example, from SiO x or AlO x At least one selected from the group of components is formed.

[0176] The refractive index of the dielectric layer 51 is, for example, less than 2, and the refractive index of the optical waveguide 11 is, for example, not less than 2. If the difference between the two refractive indices is large, the evanescent light penetrating from the optical waveguide 11 to the dielectric layer 51 can be reduced.

[0177] Next, the measurement Fig. 9 The results of the intervals at the a to i positions and the α to δ positions shown. The intervals were investigated by retardation measurement. 75 optical waveguides 10 were used in the measurement. The a, b and c positions or the g, h and i positions are three positions of the partition walls at the ends of the plurality of partition walls 73. The d, e and f positions are three positions of the partition walls at the center of the plurality of partition walls 73. The α to δ positions are the four corner positions of the area surrounded by the sealing member 79.

[0178] The distance between the partition wall 73 and the mirror 30 in the Z direction is 0 nm in theory. The distance between the dielectric layer 51 and the electrode 62b in the Z direction is 2.9 μm in theory.

[0179] Table 1 shows the intervals at the positions a to i and the positions α to δ when the elastic spacer 77 is not present.

[0180] [Table 1]

[0181]

[0182]

[0183] In the absence of the elastic spacer 77, the average value of the intervals at the a to i positions is 0.146 nm, and the standard deviation thereof is 0.128 nm. The average value of the intervals at the α to δ positions is 3.10 μm, and the standard deviation thereof is 0.154 μm. Therefore, the average value of the intervals deviates greatly from the theoretical value described above, the dispersion of the intervals is also large, and the intervals are not uniform.

[0184] [Table 2]

[0185] place Gap(μm) place Gap(μm) a 0.003 α 2.94 b 0.007 β 2.94 c 0.005 γ 2.94 d 0.004 δ 2.94 e 0.009 average value 2.94 f 0.007 Standard Deviation 0.000 g 0.003 h 0.006 i 0.006 average value 0.006 Standard Deviation 0.002

[0186] Table 2 shows the intervals at the a to i portion and the α to δ portion when the elastic spacer 77 is present. When the elastic spacer 77 is present, the average value of the intervals at the a to i portion is 0.006 nm, and its standard deviation is 0.002 nm. The average value of the intervals at the α to δ portion is 2.94 μm, and its standard deviation is 0.000 μm. Therefore, the average value of the intervals is close to the theoretical value described above, and the dispersion of the intervals is sufficiently small, so that it can be said that the intervals are uniform. That is, in the optical device 100 of this embodiment, the uniformity of the intervals between the substrates 50a and 50b can be greatly improved by the elastic spacer 77.

[0187] In this embodiment, if Fig. 12A and Fig. 12B As shown, a portion of the upper structure 100b is cut off and removed. Fig. 12A and Fig. 12B In the example shown, the size of the upper structure 100b in the XY direction is smaller than the size of the lower structure 100a in the XY direction. Fig. 9 The elastic spacer 77 is provided in the area surrounded by the sealing member 79 and around it, and the Fig. 12A and Fig. 12B The lower structure 100a and the upper structure 100b shown are bonded together via an elastic spacer 77 to produce an optical device. The result of the investigation by the inventor of the present invention is that in this case, the average value of the interval at the a to i position is 0.01nm, and its standard deviation is 0.004nm. The average value of the interval at the α to δ position is 2.94μm, and its standard deviation is 0.007μm. Indeed, in this case, the uniformity of the interval between the substrate 50a and the substrate 50b can be greatly improved. In contrast, in the optical device 100 of the present embodiment, as described above, the average value of the interval at the a to i position is 0.006nm, and its standard deviation is 0.002nm. The average value of the interval at the α to δ position is 2.94μm, and its standard deviation is 0.000μm. Therefore, by using the technology of the present invention, the uniformity of the interval between the substrate 50a and the substrate 50b can be further improved.

[0188] In addition, in the optical device 100 of the present embodiment, the mirror 30 of the upper structure 100b is not formed in the area where the elastic spacer 77 is formed. Through such a structure, the interval in the Z direction can be obtained larger in the area where the elastic spacer 77 and the sealing member 79 are formed. Thus, the liquid sealing member 79 before solidification will not spread to more than required. In addition, when the lower structure 100a and the upper structure 100b are bonded, if the lower structure 100a and the upper structure 100b are sandwiched between larger particles, the interval after bonding is likely to become uneven. In this case, also because the interval in the Z direction of the peripheral portion that is particularly easy to mix with particles is larger in the present embodiment, the interval after bonding can be made uniform.

[0189] At least one of the mirror 30 and the mirror 40 may not be formed in the region where the elastic spacer 77 is formed. In the above example, the mirror 30 is not formed. Conversely, the mirror 40 may not be formed. Alternatively, both the mirror 30 and the mirror 40 may not be formed.

[0190] Next, a modification of the optical device 100 will be described. Fig.13 1 is a cross-sectional view schematically showing the structure of an optical device 100M according to a modified example. Fig.13 The cross section of the optical device 100M is shown Fig. 9 The CC line cross section shown corresponds to this. Fig.13 The figure above shows the state before the lower structure 101a and the upper structure 101b are bonded together. Fig.13 The figure below shows the state after the lower structure 101a and the upper structure 101b are attached. In the above-mentioned embodiment, the mirror 30 is not formed in the region where the elastic spacer 77 is formed in the upper structure 100b. In contrast, in this modification, the mirror 31 is also formed in the region where the elastic spacer 77 is formed. In this modification, the interference between adjacent waveguides 10, that is, crosstalk, can be greatly reduced.

[0191] Next, the results of measuring the light emitted from the optical device 100 of the present embodiment will be described.

[0192] Fig.14 Schematic diagram of light emission from the optical device 100. Fig.14 In the example shown, the light emitted from the optical device 100 is measured by a photodetector (not shown) fixed to a direction of an emission angle θ=60°. In this measurement, a 589 nm laser is input into each optical waveguide 11 via a grating 13. It can be seen that when the elastic spacer 77 is present, the intensity of the measured light is about 100 to about 1000 times higher than when the elastic spacer 77 is not present. That is, in the optical device 100 of this embodiment, the elastic spacer 77 can greatly improve the intensity of the emitted light and the accuracy of the emission angle.

[0193] <Manufacturing method>

[0194] An example of a method for manufacturing the above-mentioned optical device 100 will be described below.

[0195] Fig.15 1 is a flowchart showing an example of a manufacturing process of the optical device 100. The manufacturing method of the optical device 100 of this example includes the following steps S101 to S106.

[0196] In step S101, a substrate 50a having a first surface 50as and a substrate 50b having a second surface 50bs are prepared. In step S102, a plurality of partition walls 73 are formed on the first surface 50as. In step S103, an elastic spacer 77 is formed on the first surface 50as or the second surface 50bs at a location that is located around the plurality of partition walls 73 in the completed state. In step S104, a sealing member 79 is applied to the first surface 50as or the second surface 50bs at a location that surrounds the plurality of partition walls 73 in the completed state and does not have the elastic spacer 77. In step S105, the sealing member 79 is cured in a state where the sealing member 79 is in close contact with the first surface 50as and the second surface 50bs, thereby bonding the substrate 50a to the substrate 50b. In step S106, a portion of the substrate 50a or the substrate 50b where the elastic spacer 77 is not provided is cut and removed to expose a portion of the elastic spacer 77.

[0197] The step of providing a plurality of dielectric members 21 between the plurality of partition walls 73 may be included after step S102. When the dielectric members 21 include a liquid crystal material, the step of injecting a plurality of dielectric members 21 between the plurality of partition walls 73 may be included after step S105.

[0198] The optical device 100 can be manufactured through the above method.

[0199] <Application Examples>

[0200] Fig.1611 is a diagram showing a structural example of an optical scanning device 100 in which components such as a spectrometer 90, a waveguide array 10A, a phase shifter array 80A, and a light source 130 are integrated on a circuit substrate (e.g., a chip). The light source 130 may be, for example, a light-emitting element such as a semiconductor laser. The light source 130 in this example emits light of a single wavelength whose wavelength in free space is λ. The spectrometer 90 branches the light from the light source 130 and introduces it into the waveguides of a plurality of phase shifters. In the example shown in FIG. 11 , an electrode 62A and a plurality of electrodes 62B are provided on the chip. For the waveguide array 10A, a control signal is supplied from the electrode 62A. For the plurality of phase shifters 80 in the phase shifter array 80A, control signals are transmitted respectively from the plurality of electrodes 62B. The electrode 62A and the plurality of electrodes 62B can be connected to a control circuit (not shown) that generates the above-mentioned control signal. The control circuit may be provided on the chip shown in FIG. 11 or on another chip of the optical scanning device 100.

[0201] like Fig.16 As shown, by integrating all components on a chip, a large-scale optical scanning can be realized with a small device. For example, all components shown in FIG11 can be integrated on a chip of about 2 mm×1 mm.

[0202] Fig.17 This is a schematic diagram showing a state where a two-dimensional scan is performed by irradiating a laser beam or the like from the optical scanning device 100 to a distant place. The two-dimensional scan is performed by moving the beam spot 310 in the horizontal and vertical directions. For example, by combining with the well-known TOF (Time Of Flight) method, a two-dimensional distance measurement image can be obtained. The TOF method is a method of calculating the flight time of the light and finding the distance by irradiating a laser beam and observing the reflected light from the object.

[0203] Fig.181 is a block diagram showing a structural example of a LiDAR system 300 as an example of a light detection system capable of generating such a distance measurement image. The LiDAR system 300 includes a light scanning device 100, a light detector 400, a signal processing circuit 600, and a control circuit 500. The light detector 400 detects light emitted from the light scanning device 100 and reflected from an object. The light detector 400 can be, for example, an image sensor having sensitivity to the wavelength λ of the light emitted from the light scanning device 100, or a light detector including a light receiving element such as a photodiode. The light detector 400 outputs an electrical signal corresponding to the amount of light received. The signal processing circuit 600 calculates the distance to the object based on the electrical signal output from the light detector 400 and generates distance distribution data. The distance distribution data is data representing a two-dimensional distribution of distances (i.e., a distance measurement image). The control circuit 500 is a processor that controls the light scanning device 100, the light detector 400, and the signal processing circuit 600. The control circuit 500 controls the timing of irradiating a light beam from the optical scanning device 100 and the timing of exposure and signal reading of the photodetector 400 , and instructs the signal processing circuit 600 to generate a distance measurement image.

[0204] In two-dimensional scanning, as a frame rate for obtaining ranging images, for example, it is possible to select from 60fps, 50fps, 30fps, 25fps, 24fps, etc., which are often used in motion images. In addition, if the application to the vehicle-mounted system is considered, the greater the frame rate, the higher the frequency of obtaining ranging images, and the more accurately obstacles can be detected. For example, when driving at 60km / h, at a frame rate of 60fps, an image can be obtained every time the car moves about 28cm. At a frame rate of 120fps, an image can be obtained every time the car moves about 14cm. At a frame rate of 180fps, an image can be obtained every time the car moves about 9.3cm.

[0205] The time required to obtain a distance measurement image depends on the speed of the light beam scanning. For example, in order to obtain an image with a resolution of 100×100 points at 60fps, it is necessary to scan the light beam at 1.67μs or less per point. In this case, the control circuit 500 controls the emission of the light beam by the light scanning device 100 and the signal accumulation and reading by the light detector 400 at an operating speed of 600kHz.

[0206] <Application example to optical receiving equipment>

[0207] The optical scanning device in the above-mentioned embodiment of the present invention can also be used as an optical receiving device with a substantially similar structure. The optical receiving device includes a waveguide array 10A similar to the optical scanning device, and a first adjustment element for adjusting the direction of the receivable light. Each first mirror 30 of the waveguide array 10A transmits light incident from the third direction to the opposite side of the first reflection surface. Each optical waveguide layer 20 of the waveguide array 10A propagates the light transmitted through the first mirror 30 in the second direction. The first adjustment element can change the direction of the receivable light by changing at least one of the refractive index and thickness of the optical waveguide layer 20 in each waveguide element 10 and the wavelength of the light. Furthermore, when the optical receiving device includes a plurality of phase shifters 80, or 80a and 80b similar to the optical scanning device, and a second adjustment element for changing the phase difference of the light output from the plurality of waveguide elements 10 through the plurality of phase shifters 80, or 80a and 80b, respectively, the direction of the receivable light can be changed two-dimensionally.

[0208] For example, it can constitute Fig.16 The light source 130 in the optical scanning device 100 shown is replaced with an optical receiving device of the receiving circuit. If light of wavelength λ is incident on the waveguide array 10A, the light is transmitted to the optical splitter 90 through the phase shifter array 80A, and finally concentrated to one part and transmitted to the receiving circuit. The intensity of the light concentrated in the one part can be said to represent the sensitivity of the optical receiving device. The sensitivity of the optical receiving device can be adjusted by adjusting elements respectively assembled to the waveguide array and the phase shifter array 80A. In the optical receiving device, for example, Figure 4 In the figure, the directions of the wave number vectors (thick arrows in the figure) become opposite. The incident light has a light component in the direction in which the waveguide element 10 extends (the X direction in the figure) and a light component in the arrangement direction of the waveguide element 10 (the Y direction in the figure). The sensitivity of the light component in the X direction can be adjusted by an adjustment element assembled to the waveguide array 10A. On the other hand, the sensitivity of the light component in the arrangement direction of the waveguide element 10 can be adjusted by an adjustment element assembled to the phase shifter array 80A. According to the phase difference Δφ of the light when the sensitivity of the light receiving device becomes maximum, the refractive index n of the optical waveguide layer 20 w and thickness d, we can know Figure 4 θ and α0 are shown. Therefore, the incident direction of light can be determined.

[0209] According to the above, refer to Fig. 12A and Fig. 12B The structure and operation of the optical device 100 of the present embodiment as an optical scanning device or an optical receiving device are summarized as follows in the illustrated example.

[0210] In the optical device 100 of this embodiment, the plurality of dielectric members 21 include liquid crystal material or electro-optical material. The plurality of dielectric members 21 are sandwiched between a pair of electrodes 62a and 62b for voltage application. That is, the plurality of optical waveguides 10 have a structure capable of adjusting the refractive index of the plurality of dielectric members 21.

[0211] When the optical device 100 of this embodiment is used as an optical scanning device, the direction of light emitted from the plurality of optical waveguides 10 via the substrate 50a or the substrate 50b changes by adjusting the refractive index of the plurality of dielectric members 21. More specifically, the X-direction component of the wave number vector of the light changes.

[0212] When the optical device 100 of this embodiment is used as a light receiving device, the incident direction of light introduced into the plurality of optical waveguides 10 via the substrate 50a or 50b changes by adjusting the refractive index of the plurality of dielectric members 21. More specifically, the X-direction component of the wave number vector of the light changes.

[0213] The optical device 100 of the present embodiment may further include a plurality of phase shifters 80 connected directly or via other waveguides to the plurality of optical waveguides 10. When the number of the optical waveguide 10 is one, the number of the phase shifter 80 is also one.

[0214] When the optical device 100 of this embodiment is used as an optical scanning device, the direction of light emitted from the plurality of optical waveguides 10 via the substrate 50a or the substrate 50b is changed by changing the phase difference of the light passing through the plurality of phase shifters 80. More specifically, the Y-direction component of the wave number vector of the light is changed.

[0215] When the optical device 100 of this embodiment is used as a light receiving device, the incident direction of the light taken into the plurality of optical waveguides 10 via the substrate 50a or the substrate 50b is changed by changing the phase difference of the light passing through the plurality of phase shifters 80. More specifically, the Y-direction component of the wave number vector of the light is changed.

[0216] The above-mentioned embodiments can be combined appropriately.

[0217] Industrial Applicability

[0218] The optical scanning device and the optical receiving device according to the embodiment of the present invention can be used for applications such as a laser radar system mounted on a vehicle such as an automobile, a UAV, or an AGV.

[0219] Description of symbols

[0220] 10 Waveguide components, optical waveguides

[0221] 11 Optical waveguide

[0222] 10A Waveguide Array

[0223] 13 Grating

[0224] 15 Grating

[0225] 20 Optical waveguide layer

[0226] 21 Dielectric components

[0227] 30 Mirror 1

[0228] 40 Mirror 2

[0229] 50a, 50b base plate

[0230] 51 Dielectric layer

[0231] 62a, 62b, 62A, 62B Electrode

[0232] 73 Multiple partition walls

[0233] 80 Phase Shifter

[0234] 80A Phase Shifter Array

[0235] 90 Splitter

[0236] 100, 100A optical scanning equipment

[0237] 110 Driving Circuit of Waveguide Array

[0238] 130 Light Source

[0239] 210 Driving Circuit of Phase Shifter Array

[0240] 310 beam spots

[0241] 400 Light Detector

[0242] 500 Control Circuit

[0243] 600 Signal Processing Circuit

Claims

1. An optical device, wherein: have: A first substrate having a first surface extending along a first direction and a second direction intersecting the first direction; A second substrate having a second surface at least partially opposed to the first surface, the second surface having an area different from that of the first surface; a plurality of optical waveguides extending along the first direction between the first substrate and the second substrate, each of the plurality of optical waveguides comprising a first portion and a second portion, the first portion being disposed between the first substrate and the second substrate and in a region where the first substrate and the second substrate overlap, and the second portion being disposed in a region where the first substrate and the second substrate do not overlap; as well as A plurality of spacers, disposed on at least one of the first surface and the second surface, including a first portion and a second portion; The first portion of the plurality of spacers is at least one spacer located between the first substrate and the second substrate and in a region where the first substrate and the second substrate overlap when viewed from a direction perpendicular to the first surface; The second portion of the plurality of spacers is at least one spacer located in a region where the first substrate and the second substrate do not overlap when viewed from a direction perpendicular to the first surface; At least a portion of the second portions of the plurality of spacers is located around the second portions of the plurality of optical waveguides.

2. The optical device according to claim 1, wherein: further comprising a plurality of partition walls, the plurality of partition walls being a plurality of partition walls arranged in the second direction between the first substrate and the second substrate, each partition wall extending along the first direction; The elastic modulus of each of the plurality of spacers is smaller than the elastic modulus of each of the plurality of partition walls.

3. The optical device according to claim 2, wherein: The plurality of partition walls are directly or indirectly sandwiched by the first substrate and the second substrate; Due to the clamping of the first substrate and the second substrate, a deformation rate of each of the plurality of spacers in a direction perpendicular to the first surface is greater than a deformation rate of each of the plurality of partition walls in the perpendicular direction.

4. The optical device according to any one of claims 1 to 3, wherein: Each of the plurality of spacers has a columnar shape.

5. The optical device according to any one of claims 1 to 3, wherein: Each of the plurality of optical waveguides includes a portion located between two adjacent partition walls, and the portion is provided with a first grating.

6. The optical device according to any one of claims 1 to 3, wherein: Each of the plurality of optical waveguides includes a second grating in the second portion.

7. The optical device according to any one of claims 1 to 3, wherein: A sealing member is further provided for fixing the interval between the first substrate and the second substrate; The plurality of optical waveguides have a structure in which at least one first optical waveguide is connected to at least one second optical waveguide, respectively; When viewed from a direction perpendicular to the first surface, the sealing member surrounds the one or more first optical waveguides.

8. The optical device according to claim 7, wherein: The one or more first optical waveguides each include one or more dielectric members extending along the first direction; A region between the first substrate and the second substrate and surrounded by the sealing member is filled with the same member as the one or more dielectric members.

9. The optical device according to claim 7, wherein: The one or more first optical waveguides each include one or more dielectric members extending along the first direction; The optical device further includes two mirrors, the two mirrors being located between the first substrate and the one or more dielectric members, and between the second substrate and the one or more dielectric members, respectively.

10. The optical device according to claim 9, wherein: At least a portion of the first portion of the plurality of spacers is located outside a region sandwiched by the two mirrors.

11. The optical device according to claim 8, wherein: The one or more first optical waveguides have a structure capable of adjusting the refractive index of the one or more dielectric members; By adjusting the refractive index of the one or more dielectric components, the direction of light emitted from the one or more first optical waveguides via the first substrate or the second substrate, or the incident direction of light taken into the one or more first optical waveguides via the first substrate or the second substrate changes.

12. The optical device according to claim 11, wherein: further comprising a pair of electrodes sandwiching the one or more dielectric members; The one or more dielectric components include a liquid crystal material or an electro-optical material; The refractive index of the one or more dielectric members is adjusted by applying a voltage to the pair of electrodes.

13. The optical device according to claim 12, wherein: further comprising one or more phase shifters connected to the one or more first optical waveguides respectively directly or via other waveguides; By changing the phase difference of the light passing through the one or more phase shifters, the direction of the light emitted from the one or more first optical waveguides via the first substrate or the second substrate, or the incident direction of the light taken into the one or more first optical waveguides via the first substrate or the second substrate is changed.

14. A light detection system, wherein: have: The optical device according to any one of claims 1 to 13; a light detector for detecting light emitted from the optical device and reflected from an object; and The signal processing circuit generates distance distribution data based on the output of the photodetector.

15. A method for manufacturing an optical device, wherein: include: A step of preparing a first substrate having a first surface and a second substrate having a second surface; forming a plurality of optical waveguides extending in one direction on the first surface of the first substrate; forming a plurality of spacers on the first surface of the first substrate or on the second surface of the second substrate; a step of fixing the first substrate and the second substrate so that the first surface of the first substrate and the second surface of the second substrate face each other so that the plurality of spacers are located around the plurality of optical waveguides; and A step of cutting and removing a portion of the first substrate or the second substrate on which the plurality of spacers are not provided, so as to expose a portion of the plurality of spacers; The plurality of optical waveguides each include a first portion and a second portion, the first portion being arranged in a region where the first substrate overlaps with the second substrate, and the second portion being arranged in a region where the first substrate does not overlap with the second substrate; At least a portion of the exposed portions of the plurality of spacers is located around the second portion of each of the plurality of optical waveguides.

16. The method for manufacturing an optical device according to claim 15, wherein: Also included is the process of forming a plurality of partition walls; The step of forming the plurality of optical waveguides includes the step of providing one or more dielectric members between the plurality of partition walls, and the step of providing the one or more dielectric members is performed after the step of forming the plurality of partition walls.

17. The method for manufacturing an optical device according to claim 15, wherein: Also included is the process of forming a plurality of partition walls; The step of forming the plurality of optical waveguides further includes a step of injecting one or more dielectric members including a liquid crystal material between the plurality of partition walls, the step of injecting the one or more dielectric members including a liquid crystal material being performed after the step of fixing the first substrate and the second substrate.

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