Optical equipment

Abstract

The optical device comprises: a light deflecting device that emits a light beam having a shape extending in the second direction from a light exit surface parallel to a first direction and a second direction intersecting the first direction toward a direction intersecting the light exit surface, and is capable of changing the emission direction of the light beam along the first direction; and an optical element arranged on the path of the light beam to increase the degree of diffusion of the light beam in the second direction.

Description

Technical Field

[0001] The present disclosure relates to optical devices. Background Art

[0002] Conventionally, various devices have been proposed that scan a scene with a light beam and detect reflected light from an object included in the scene to measure the distance to the object (for example, see Patent Documents 1 and 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-128663

[0006] Patent Document 2: U.S. Patent Application Publication No. 2018 / 0224709 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] An object of the present disclosure is to provide an optical device capable of relatively easily changing the degree of divergence of a light beam.

[0009] Means used to solve problems

[0010] An optical device according to a technical solution of the present disclosure comprises: a light deflection device which emits a light beam having a shape extending in the second direction from a light exit surface parallel to a first direction and a second direction intersecting the first direction toward a direction intersecting the light exit surface, and is capable of changing the emission direction of the light beam along the first direction; and an optical element arranged on the path of the light beam to increase the degree of diffusion of the light beam in the second direction.

[0011] Effects of the Invention

[0012] According to the technology disclosed in the present invention, it is possible to realize an optical device that can relatively easily change the degree of diffusion of a light beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A It is a perspective view schematically showing an example of a light deflecting device.

[0014] Figure 1B It will Figure 1A The illustrated configuration is a diagram viewed along the +Y direction.

[0015] Figure 2 This is a perspective view schematically showing an example of an optical device according to Embodiment 1 of the present disclosure.

[0016] Figure 3A It will Figure 2The illustrated configuration is a diagram viewed along the +Y direction.

[0017] Figure 3B It will Figure 2 The illustrated configuration is a diagram viewed along the +Y direction.

[0018] Figure 4 It will Figure 2 The structure shown is a diagram viewed along the +X direction.

[0019] Figure 5A This is a graph plotting the calculation results of the relationship between the width of the light deflecting device and the divergence angle of the light beam in the case where no optical element is provided.

[0020] Figure 5B This is a graph plotting the calculation results of the relationship between the width of the light deflecting device and the divergence angle of the light beam when an optical element is included.

[0021] Figure 6A This is a perspective view schematically showing an example of an optical device according to a first modified example of the first embodiment.

[0022] Figure 6B It will Figure 6A The structure shown is a diagram viewed along the +X direction.

[0023] Figure 7A This is a perspective view schematically showing an example of an optical device according to a second modified example of the first embodiment.

[0024] Figure 7B It will Figure 7A The structure shown is a diagram viewed along the +X direction.

[0025] Figure 8A This is a perspective view schematically showing an example of an optical device according to a third modified example of the first embodiment.

[0026] Figure 8B It will Figure 8A The structure shown is a diagram viewed along the +X direction.

[0027] Figure 8C It is a diagram schematically showing the far-field intensity distribution of light beams emitted from the lens array and a single lens.

[0028] Figure 9 This is a perspective view schematically showing an example of an optical device according to a fourth modified example of the first embodiment.

[0029] Figure 10A This is a perspective view schematically showing an example of an optical device according to a fifth modified example of the first embodiment.

[0030] Figure 10B It will Figure 10AThe illustrated configuration is a diagram viewed along the +Y direction.

[0031] Figure 10C This is a perspective view schematically showing an example of an optical device according to a sixth variation of the first embodiment.

[0032] Figure 10D It will Figure 10C The illustrated configuration is a diagram viewed along the +Y direction.

[0033] Figure 10E This is a perspective view schematically showing an example of an optical device according to the seventh modified example of embodiment 1.

[0034] Figure 10F It will Figure 10E The illustrated configuration is a diagram viewed along the +Y direction.

[0035] Figure 11 This is a perspective view schematically showing an example of an optical device according to Embodiment 2 of the present disclosure.

[0036] Figure 12A It will Figure 11 The illustrated configuration is a diagram viewed along the +Y direction.

[0037] Figure 12B It will Figure 11 The illustrated configuration is a diagram viewed along the +Y direction.

[0038] Figure 13 It will Figure 11 The structure shown is a diagram viewed along the +X direction.

[0039] Figure 14 This is a perspective view schematically showing an example of an optical device according to Embodiment 3 of the present disclosure.

[0040] Figure 15A It will Figure 14 The illustrated configuration is a diagram viewed along the +Y direction.

[0041] Figure 15B It will Figure 14 The structure shown is a diagram viewed along the +X direction.

[0042] Figure 16A This is a perspective view schematically showing an example of an optical device according to a modified example of the third embodiment.

[0043] Figure 16B It will Figure 16A The illustrated configuration is a diagram viewed along the +Y direction. DETAILED DESCRIPTION

[0044] Before describing the embodiments of the present disclosure, the knowledge underlying the present disclosure will be described.

[0045] Figure 1A It is a perspective view schematically showing an example of the structure of the light deflection device 10 according to the exemplary embodiment. Figure 1B It will Figure 1A The structure shown is viewed along the +Y direction. For reference, mutually orthogonal X-axis, Y-axis, and Z-axis are schematically shown. In this specification, the direction in which the arrow of the axis points is the + direction, and the opposite direction is the - direction. The direction pointing in the +Z direction is upward, and the direction pointing in the -Z direction is downward. However, these designations are used only for convenience of explanation and do not limit the posture when the light deflection device 10 is actually used. In addition, the shape and size of the entire or part of the structure shown in the figure do not limit the actual shape and size.

[0046] The light deflection device 10 emits a light beam emitted from a light source (not shown) in a predetermined direction. The light deflection device 10 includes a first mirror 10m1, a second mirror 10m2, and an optical waveguide layer 10w. The first mirror 10m1 and the second mirror 10m2 are opposed to each other and extend in the X direction. The transmittance of the first mirror 10m1 is higher than that of the second mirror 10m2. At least one of the first mirror 10m1 and the second mirror 10m2 can be formed, for example, from a multilayer reflective film having a plurality of high-refractive index layers and a plurality of low-refractive index layers alternately stacked. The first mirror 10m1 and the second mirror 10m2 can also be formed from a multilayer reflective film having the same high-refractive index layers and the same low-refractive index layers. In this case, if the number of stacked layers of the first mirror 10m1 is smaller than that of the second mirror 10m2, the transmittance of the first mirror 10m1 is higher than that of the second mirror 10m2. The optical waveguide layer 10w is located between the first mirror 10m1 and the second mirror 10m2.

[0047] The first mirror 10m1 has a light exit surface 10s parallel to the XY plane on the side opposite the optical waveguide layer 10w. Light 10L propagates along the X-direction within the optical waveguide layer 10w while being reflected by the first mirror 10m1 and the second mirror 10m2. At this point, a portion of light 10L is emitted from the light exit surface 10s as a light beam 10b. The direction of the central axis of light beam 10b depends on the refractive index and / or thickness of the optical waveguide layer 10w. In this specification, the direction of the central axis of light beam 10b is simply referred to as the "emission direction of light beam 10b."

[0048] The optical waveguide layer 10w may have a structure in which the refractive index and / or thickness changes according to the change of the applied driving voltage. Figure 1BIn the example shown, the optical waveguide layer 10w comprises a liquid crystal material, and two electrodes 10e for applying a driving voltage may be provided on the optical waveguide layer 10w. When the driving voltage is varied by inputting a control signal from a control circuit (not shown), the refractive index of the optical waveguide layer 10w changes, causing the direction of the light beam 10b emitted from the light exit surface 10s to change along the X direction. In another example, the optical waveguide layer 10w comprises a gas or liquid, and an actuator that deforms when a driving voltage is applied may be attached to the first mirror 10m1 and / or the second mirror 10m2. When the driving voltage is varied by inputting a control signal from a control circuit (not shown), the thickness of the optical waveguide layer 10w changes as the mirror spacing changes due to the deformation of the actuator, causing the direction of the light beam 10b emitted from the light exit surface 10s to change along the X direction. As described above, the optical deflection device 10 can change the direction of the light beam 10b emitted from the light exit surface 10s along the X direction in response to an external control signal. Figure 1A The thick line parallel to the X direction represents the scanning direction of the light beam 10b.

[0049] Details such as the operating principle and operating method of the light deflection device 10 are disclosed in U.S. Patent Application Publication No. 2018 / 0224709, the entire disclosure of which is incorporated herein by reference.

[0050] Next, the shape of the light beam 10b is described. When a screen perpendicular to the emission direction of the light beam 10b exists in the far field, the shape of the light beam 10b refers to the shape of the light spot obtained by the light beam 10b irradiating the screen. Figure 1A As shown, the light beam 10b emitted from the light emitting surface 10s extending in the X direction has a shape extending in the Y direction such as a line or an ellipse in the far field. Figure 1A As shown, the divergence angle of the light beam 10b in the Y direction is larger than the divergence angle of the light beam 10b in the X direction.

[0051] When the light deflection device 10 is used in a LiDAR (Light Detecting and Ranging) system that measures the distance to an object using light, the degree of divergence of the light beam 10b in the Y direction is appropriately adjusted depending on the application of the LiDAR system. When the LiDAR system is applied to a mobile object such as an automobile, by changing the direction of the light beam extending horizontally along the road, the distance to a nearby object can be measured with a small number of scans. On the other hand, by relatively reducing the divergence of the light beam 10b in the horizontal direction of the road, the irradiation energy per unit area of ​​the light beam 10b is increased, making it possible to measure the distance to a distant object.

[0052] The degree of Y-direction divergence of the light beam 10b emitted from the light deflection device 10 is determined by the structure of the light deflection device 10, specifically, the width of the light exit surface 10s in the Y direction. The narrower the Y-direction width of the light exit surface 10s, the greater the Y-direction divergence of the light beam 10b; the wider the Y-direction width of the light exit surface 10s, the smaller the Y-direction divergence of the light beam 10b. However, structural design alone cannot significantly alter the divergence of the light beam 10b.

[0053] In the optical device according to the embodiment of the present disclosure, by arranging an optical element on the path of the light beam 10 b emitted from the light deflection device 10 , the degree of spread of the light beam 10 b in the Y direction can be greatly changed.

[0054] The optical device related to the first technical solution includes: a light deflection device that emits a light beam having a shape extending in the second direction from a light exit surface parallel to the first direction and a second direction intersecting the first direction toward a direction intersecting the light exit surface, and is capable of changing the emission direction of the light beam along the first direction; and an optical element arranged on the path of the light beam to increase the degree of diffusion of the light beam in the second direction.

[0055] In this optical device, a light beam whose degree of diffusion is expanded can scan a wider range with fewer times.

[0056] The optical device according to the second technical solution is the optical device according to the first technical solution, wherein the optical element includes at least one lens having a curvature in the second direction.

[0057] In this optical device, as a result of a light beam emitted from an optical element passing through a lens, the degree of divergence of the light beam is changed.

[0058] The optical device according to the third technical solution is the optical device according to the second technical solution, wherein the lens is a concave lens.

[0059] In this optical device, the concave lens can increase the degree of divergence of the light beam emitted from the optical element.

[0060] The optical device according to a fourth technical solution is the optical device according to the second technical solution, wherein the lens is a convex lens.

[0061] In this optical device, the convex lens can increase or decrease the degree of divergence of the light beam emitted from the optical element.

[0062] The optical device according to a fifth aspect is the optical device according to any one of the second to fourth aspects, wherein the optical element includes a portion where the curvature of the lens changes along the first direction.

[0063] In this optical device, even if the emission angle of the light beam changes, changes in the spread of the light beam emitted from the optical element can be suppressed.

[0064] The optical device according to a sixth aspect is the optical device according to any one of the first to fifth aspects, wherein the optical element is in contact with the light emitting surface of the light deflecting device.

[0065] In this optical device, the overall size can be reduced by bringing the optical element into contact with the light emitting surface of the light deflecting device.

[0066] According to a seventh aspect of the present invention, in the optical device according to the first aspect, the optical element includes at least one mirror having a curvature in the second direction, and the mirror reflects the light beam emitted from the light emitting surface of the light deflecting device.

[0067] In this optical device, the degree of divergence of a light beam emitted from an optical element is changed as a result of the light beam being reflected by a mirror.

[0068] The optical device according to the eighth technical solution is the optical device according to the seventh technical solution, wherein the mirror is a convex mirror.

[0069] In this optical device, the convex mirror can increase the degree of divergence of the light beam emitted from the optical element.

[0070] The optical device according to a ninth technical solution is the optical device according to the seventh technical solution, wherein the mirror is a concave mirror.

[0071] In this optical device, the concave mirror can increase or decrease the degree of divergence of the light beam emitted from the optical element.

[0072] The optical device according to a tenth technical solution is the optical device according to any one of the seventh to ninth technical solutions, wherein the optical element includes a portion where the curvature of the mirror changes along the first direction.

[0073] In this optical device, even if the emission angle of the light beam changes, changes in the spread of the light beam reflected by the mirror can be suppressed.

[0074] The optical device according to the 11th technical solution is an optical device according to any one of the first to tenth technical solutions, wherein the light deflecting device includes: a first mirror and a second mirror, which are opposed to each other and extend in the first direction; and an optical waveguide layer, which is located between the first mirror and the second mirror and causes light to propagate in the first direction.

[0075] In this optical device, part of the light propagating through the optical waveguide layer is emitted to the outside.

[0076] The optical device according to the twelfth technical solution is the optical device according to any one of the first to tenth technical solutions, wherein the light deflecting device includes: a plurality of optical waveguides arranged along the first direction and extending along the second direction; and a plurality of phase shifters connected to the plurality of optical waveguides, respectively.

[0077] In this optical device, part of the light that passes through the plurality of phase shifters and enters the plurality of optical waveguides is emitted to the outside.

[0078] The optical device according to a thirteenth technical solution is the optical device according to the twelfth technical solution, wherein a grating is provided on each of the plurality of optical waveguides, and the light beam is emitted through the grating.

[0079] In this optical device, a light beam formed by superimposing a plurality of diffracted lights is emitted through a grating.

[0080] The optical device related to the 14th technical solution comprises: a light deflecting device that emits a light beam having a shape extending in the above-mentioned second direction from a light exit surface parallel to the first direction and a second direction intersecting the above-mentioned first direction toward the direction intersecting the above-mentioned light exit surface, and is capable of changing the emission direction of the above-mentioned light beam along the above-mentioned first direction; and an optical element that is arranged on the path of the above-mentioned light beam and changes the degree of diffusion of the above-mentioned light beam in the above-mentioned second direction; the above-mentioned optical element has a first surface on which the above-mentioned light beam is incident and a second surface from which the above-mentioned light beam is emitted; and the distance between the above-mentioned light exit surface and the above-mentioned first surface or the above-mentioned second surface of the above-mentioned optical element along the direction perpendicular to the above-mentioned light exit surface changes along the above-mentioned first direction.

[0081] In this optical device, changes in the shape and intensity distribution of the light beam caused by beam scanning can be suppressed.

[0082] The optical device according to the fifteenth technical solution is the optical device according to the fourteenth technical solution, wherein the optical element includes at least one lens having a curvature in the second direction, and has a portion where the curvature of the lens changes along the first direction.

[0083] In this optical device, even if the curvature of the lens for the light beam is not strictly constant regardless of the emission angle, changes in the shape and intensity distribution of the light beam due to changes in the emission angle can be suppressed.

[0084] In the optical device related to the 16th technical solution, in the optical device related to the 14th technical solution, the above-mentioned optical element includes at least one lens having a curvature in the above-mentioned second direction, and has a portion in which the above-mentioned curvature of the above-mentioned lens is constant along the above-mentioned first direction; the above-mentioned first surface or the above-mentioned second surface of the above-mentioned portion of the above-mentioned optical element is inclined along the above-mentioned first direction relative to the above-mentioned light emitting surface.

[0085] In this optical device, the curvature of the lens can be kept constant along the first direction while suppressing changes in the optical path length depending on the emission angle. As a result, changes in the shape and intensity distribution of the light beam accompanying the beam scanning can be suppressed.

[0086] In the present disclosure, all or part of a circuit, unit, device, component or section, or all or part of a functional block in a block diagram may be implemented, for example, by one or more electronic circuits including a semiconductor device, a semiconductor integrated circuit (IC) or an LSI (large scale integration). An LSI or an IC may be integrated onto a single chip or may be composed of a combination of multiple chips. For example, functional blocks other than storage elements may be integrated into a single chip. Although referred to herein as LSI or IC, the term may vary depending on the degree of integration and may also be referred to as system LSI, VLSI (very large scale integration) or ULSI (ultra large scale integration). A Field Programmable Gate Array (FPGA) programmed after the manufacture of the LSI, or a reconfigurable logic device capable of reconfiguring the bonding relationship within the LSI or setting the circuit partitions within the LSI may also be used for the same purpose.

[0087] Furthermore, all or part of the functions or actions of a circuit, unit, device, component, or section can be executed through software processing. In this case, the software is recorded on one or more non-transitory recording media such as ROMs, optical disks, and hard disk drives. When the software is executed by a processor, the functions determined by the software are executed by the processor and peripheral devices. The system or device may also include one or more non-transitory recording media with the software recorded, a processor, and necessary hardware devices such as interfaces.

[0088] In the present disclosure, “light” refers not only to visible light (wavelength of about 400 nm to about 700 nm) but also to electromagnetic waves including ultraviolet light (wavelength of about 10 nm to about 400 nm) and infrared light (wavelength of about 700 nm to about 1 mm).

[0089] The following describes a more specific embodiment of the present disclosure. However, there are cases where the detailed description required above is omitted. For example, there are cases where the detailed description of well-known matters and the repeated description of substantially the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the inventors provide the drawings and the following description to enable those skilled in the art to fully understand the present disclosure, 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.

[0090] (Implementation Method 1)

[0091] First, refer to Figure 2 A basic configuration example of an optical device according to Embodiment 1 of the present disclosure will be described. Figure 2 : is a perspective view schematically showing an example of the optical device 100 according to the first embodiment of the present disclosure. Figure 2 In order to facilitate understanding of the description, the components are shown in a separated state, but these components may also be in contact with each other. The same applies to the following perspective views. The optical device 100 of the first embodiment includes a light deflection device 10 and an optical element 20.

[0092] Regarding the light deflection device 10 of the first embodiment, as shown in FIG. Figure 1A and Figure 1B As described above. The light source may include, for example, a semiconductor laser element. The wavelength of the light beam emitted from the light source may be selected according to the intended use. When measuring the distance to an object using infrared light, the wavelength of the light beam may be, for example, 700 nm or greater and 2.5 μm or less. The wavelength of the light beam may also be within the visible range, i.e., approximately 400 nm or greater and 700 nm or less. The wavelength of the light beam may also be 2.5 μm or greater.

[0093] The optical element 20 of the first embodiment includes a lens 20a and a medium 20b supporting the lens 20a. The optical element 20 is arranged on the path of the light beam 10b emitted from the light deflection device 10. The lens 20a is a plano-concave lens having an upper surface 20as1 and a lower surface 20as2. Figure 2In the figure, the curvature of the lens 20a is exaggerated. The lens 20a has a curvature in the Y direction on the upper surface 20as1 and a flat bottom surface on the lower surface 20as2. The curvature is determined by the inverse of the radius of curvature. The lens 20a is a cylindrical lens having a structure extending in the X direction. The lens 20a may have a curvature in the Y direction on at least one of the upper surface 20as1 and the lower surface 20as2. The radius of curvature may be, for example, greater than 1 mm and less than 100 mm. The medium 20b has the same refractive index as the lens 20a, but may also have a different refractive index. The medium 20b is in contact with the light exit surface 10s of the light deflecting device 10. Depending on the application, the medium 20b may not be in contact with the light exit surface 10s of the light deflecting device 10. The medium 20b may also be air, water, or a vacuum. The optical element 20 does not need to include both the lens 20a and the medium 20b, but may include only at least one of them. The optical element 20 may have a length in the X direction of, for example, 1 mm to 5 mm, a width in the Y direction of, for example, 1 mm to 10 mm, and a height in the Z direction of, for example, 1 mm to 10 mm.

[0094] Next, refer to Figure 3A and Figure 3B , a description will be given of a change in the emission direction of the light beam 10 b emitted from the light emission surface 10 s of the light deflecting device 10 . Figure 3A and Figure 3B It will Figure 2 The structure shown is a diagram viewed along the +Y direction. Figure 3A and Figure 3B In the example shown, the light deflection device 10 and the optical element 20 are arranged so that the surfaces viewed along the +X direction are aligned. By changing the refractive index and / or thickness of the light waveguide layer 10w, the emission direction of the light beam 10b is changed along the X direction. Figure 3A and Figure 3B In the example shown, the emission angle of the light beam 10b is from Change to The emission angle of the light beam 10 b corresponds to the angle formed by the plane parallel to the YZ plane and the light beam 10 b. and Both have positive values. Figure 3A and Figure 3B As shown, part of the light 10L propagating in the optical waveguide layer 10w is emitted from the light emitting surface 10s, so the intensity of the light 10L decreases along the X direction. Let the distance when the intensity of the light 10L is 1 / e times be the propagation length l x e is the base of the natural logarithm. In order to make the entire light beam 10b after passing through the optical element 20 be effectively emitted from the upper surface 20as1 of the lens 20a of the optical element 20 to the outside, the length L in the X direction of the optical element 20 x is designed to be longer than the propagation length lx Specifically, according to the propagation length l x , the maximum emission angle of light beam 10b and the height L of the optical element 20 in the Z direction z The length L of the optical element 20 is designed x The light beam 10b is refracted by the upper surface 20as1 of the lens 20a and emitted to the outside.

[0095] Next, refer to Figure 4 The degree of diffusion of the light beam 10 b in the Y direction after passing through the optical element 20 will be described. Figure 4 It will Figure 2 The configuration shown is viewed along the +X direction. The arrowed rays indicate the propagation of light beam 10b emitted from the light deflection device 10. The optical element 20 uses refraction to cause incident light to be emitted in a direction different from the incident direction. The diffraction effect can be used instead of refraction, or both. While light beam 10b microscopically emerges from a light exit surface 10s having a width in the Y direction, for simplicity of explanation, it is represented as emerging from a single point.

[0096] The structure of the optical element 20 is as follows. Let the refractive index of the lens 20a and the medium 20b be n. Let the half-angle of the divergence of the light beam 10b emitted from the light exit surface 10s and propagating within the medium 20b be θ1. Let the half-angle of the divergence of the light beam 10b emitted from the lens 20a be θ2. Let the width of the light deflection device 10 be w. The width of the light deflection device 10 is equal to the width of the light exit surface 10s. Let the half-width of the lens 20a in the Y direction be r0, and let the focal length of the lens 20a when viewed along the emission direction of the light beam 10b be f. Let the distance between the principal point H of the lens 20a and the focal point F of the light propagating within the medium 20b be s1. Let the distance between the principal point H of the lens 20a and the focal point F of the light beam emitted to the outside be -s2. The principal point H is the principal point when the emission direction of the light beam 10 b from the optical element 20 is the optical axis, and s1 and −s2 are distances along the emission direction of the light beam 10 b within the optical element 20 .

[0097] First, the divergence angle θ1 of the light beam 10b emitted from the light exit surface 10s will be described. The intensity distribution of the light beam 10b in the Y direction emitted from the light exit surface 10s exhibits a nearly rectangular shape in the near field, with the width of this shape assumed to be the width w of the light deflection device 10. If the wavelength of the light beam 10b is λ, the light intensity I at a point y away from the center of the light deflection device 10 in the Y direction and at a point z away from the light exit surface 10s in the Z direction is expressed by the following equation (1).

[0098] [Formula 1]

[0099]

[0100] The Y-direction distribution of light intensity I has a central peak called a main lobe and multiple small peaks on either side thereof. If the width of the beam 10b is defined as the width of the main lobe, the half width of the main lobe is expressed by the following equation (2).

[0101] [Formula 2]

[0102]

[0103] The divergence angle θ1 of the light beam 10b is expressed by the following equation (3).

[0104] [Formula 3]

[0105]

[0106] Based on the equations (2) and (3), the diffusion angle θ1 is expressed by the following equation (4).

[0107] [Formula 4]

[0108]

[0109] When the diffusion angle θ1 is sufficiently small, the diffusion angle θ1 is approximately expressed by the following formula (5).

[0110] [Formula 5]

[0111]

[0112] According to equation (4) or equation (5), when the wavelength λ is constant, the smaller w is, the larger the diffusion angle θ1 is, and the larger w is, the smaller the diffusion angle θ1 is.

[0113] Next, the divergence angle θ2 of the light beam 10b emitted from the optical element 20 to the outside will be described. Figure 4 In the example shown, the curvature of the lens 20 a is actually gentle, and the distance between the upper surface 20 as1 and the lower surface 20 as2 of the lens 20 a is relatively short compared to the distance s1 .

[0114] When the light beam 10b having a diffusion angle θ1 enters the lens 20a with a radius r, the distance s1 is approximately expressed by the following equation (6).

[0115] [Formula 6]

[0116]

[0117] Here, the distance s1 and the distance s2 satisfy the following formula (7).

[0118] [Formula 7]

[0119]

[0120] If the equation (7) is transformed, the distance s2 is expressed by the following equation (8).

[0121] [Formula 8]

[0122]

[0123] Therefore, the divergence angle θ2 of the light beam 10b is approximately expressed by the following equation (9).

[0124] [Formula 9]

[0125]

[0126] When lens 20a is a plano-concave lens, since focal length f is represented by a negative value, the smaller the absolute value of focal length f and the larger r, the larger the diffusion angle θ2. Assuming that lens 20a is a lens having a plano-concave shape at least in the Y direction, and assuming that the radius of curvature of the plano-concave lens is R, focal length f is expressed by the following equation (10).

[0127] [Formula 10]

[0128]

[0129] When equation (10) is substituted into equation (9), the diffusion angle θ2 is expressed by the following equation (11).

[0130] [Formula 11]

[0131]

[0132] According to formula (11), the smaller R is, the larger the diffusion angle θ2 is, and the larger r is, the larger the diffusion angle θ2 is.

[0133] Next, refer to Figure 5A and Figure 5B , which explains to what extent the divergence angle θ2 of the light beam 10b changes compared to the divergence angle θ1. Figure 5A 1 is a graph plotting calculation results of the relationship between the width w of the light deflecting device 10 and the divergence angle θ1 of the light beam 10 b in the absence of the optical element 20 . Figure 5B Graph showing the calculated relationship between the width w of the light deflecting device 10 and the divergence angle θ2 of the light beam 10b when the optical element 20 is present. Figure 5A and Figure 5B In the example shown, the wavelength of the light beam 10 b is λ=940 nm, and the width w of the light deflecting device 10 is greater than or equal to 1 μm and less than or equal to 10 μm.

[0134] The reason for designing the width w of the light deflection device 10 within this range is as follows. If the light deflection device 10 is manufactured with high processing precision to make the width w of the light deflection device 10 narrower than 1 μm, manufacturing costs will increase. Furthermore, the narrower the width w of the light deflection device 10, the greater the leakage of light 10L propagating through the optical waveguide layer 10 w in the Y direction. This increased leakage reduces the propagation efficiency of the light 10L within the optical waveguide layer 10 w, and the efficiency of the light beam 10 b emitted from the light exit surface 10 s decreases. Furthermore, this increased leakage also contributes to the light beam 10 b, substantially widening the width of the light exit surface 10 s in the Y direction and preventing the desired increase in the divergence angle θ1 of the light beam 10 b. On the other hand, if the width w of the light deflection device 10 is wider than 10 μm, the size of the chip containing the light deflection device 10 increases, increasing manufacturing costs.

[0135] exist Figure 5A In the example shown, the relationship between the width w of the light deflecting device 10 and the divergence angle θ1 of the light beam 10b is calculated by taking into account the leakage of light from the optical waveguide layer 10w in addition to equation (4). If the width w of the light deflecting device 10 is designed to be within the range of 1 μm to 10 μm, the divergence angle θ1 of the light beam 10b will be 6° to 34°.

[0136] exist Figure 5B In the example shown, the relationship between the width w of the light deflecting device 10 and the divergence angle θ2 of the light beam 10b is calculated by taking into account the leakage of light from the optical waveguide layer 10w to the outside in addition to equations (4), (6), and (11). The refractive index of the optical element 20 is set to n = 1.451, the radius of curvature of the plano-concave lens is set to R = 2.5 mm, and the distance from the focal point F of the light propagating in the medium 20b is set to s1 = 2 mm, 4 mm, or 6 mm. Figure 5B The dashed portion shown represents a divergence angle θ2 that cannot be achieved because the radius r of the light beam 10 b exceeds the curvature radius R of the lens 20 a .

[0137] exist Figure 5B In the example shown, when s1 = 2 mm, if the width w of the light deflecting device 10 is designed to be within the range of 1 μm to 10 μm, the divergence angle θ2 of the light beam 10b is 8° to 42°. Figure 5A In the example shown, within the same width w, the divergence angle θ1 of the light beam 10 b is greater than or equal to 6° and less than or equal to 34°.

[0138] Likewise, in Figure 5BIn the example shown, when s1 = 4 mm, if the width w of the light deflecting device 10 is designed to be within the range of 1 μm to 10 μm, the divergence angle θ2 of the light beam 10b is 10° to 36°. Figure 5A In the example shown, within the range of the same width w, the divergence angle θ1 of the light beam 10 b is greater than or equal to 6° and less than or equal to 23°.

[0139] Likewise, in Figure 5B In the example shown, when s1 = 6 mm, if the width w of the light deflecting device 10 is designed to be within the range of 1 μm to 10 μm, the divergence angle θ2 of the light beam 10b is 12° to 33°. Figure 5A In the example shown, within the same width w, the divergence angle θ1 of the light beam 10 b is greater than or equal to 6° and less than or equal to 17°.

[0140] In all cases where s1 = 2 mm, 4 mm, and 6 mm, the divergence angle θ2 of the light beam 10b with the optical element 20 is larger than the divergence angle θ1 of the light beam 10b without the optical element 20. Thus, by providing the optical element 20 to the light deflection device 10, the divergence angle θ2 of the light beam 10b can be increased without requiring high processing accuracy to narrow the width w of the light deflection device 10. This allows the light beam 10b to scan a wider area with fewer scans. In the optical device 100 of Embodiment 1, a light beam 10b having a degree of divergence appropriate to the intended application can be easily obtained.

[0141] (Variation of Embodiment 1)

[0142] Next, refer to 6A to 10B First to fifth variations of the optical device 100 according to Embodiment 1 are described. The optical element 20 of the optical device 100 may include Figure 2 Lenses other than the plano-concave lens 20a shown extend in the X direction.

[0143] Figure 6A This is a perspective view schematically showing an example of an optical device 110 according to a first modification of the first embodiment. Figure 6B It will Figure 6A The structure shown is viewed along the +X direction. The optical device 110 of the first modified example is different from the optical device 100 of the first embodiment in that the lens 20a included in the optical element 20 is a plano-convex lens. Figure 6A and Figure 6B In the example shown, the curvature of the plano-convex lens 20a in the Y direction is relatively small. Unlike the above example, the divergence angle θ2 of the light beam 10b is reduced. Because the irradiation energy per unit area of ​​the light beam 10b is higher, this light beam 10b can scan distant objects.

[0144] Figure 7A This is a perspective view schematically showing an example of an optical device 120 according to a second modified example of the first embodiment. Figure 7B It will Figure 7A The configuration shown is viewed along the +X direction. Optical device 120 of the second modified example differs from optical device 110 of the first modified example in that convex lens 20a has a relatively large curvature in the Y direction. After exiting convex lens 20a, light beam 10b is first focused and then diffused. In this case, the diffusion angle θ2 of light beam 10b increases.

[0145] like Figure 6B and Figure 7B As shown, the divergence angle θ2 of the light beam 10b can be expanded or reduced according to the curvature of the convex lens 20a.

[0146] Figure 8A This is a perspective view schematically showing an example of an optical device 130 according to a third modified example of the first embodiment. Figure 8B It will Figure 8A The structure shown is a diagram observed along the +X direction. The optical device 130 of the third variant is different from the optical device 100 of embodiment 1 in that the lens 20a included in the optical element 20 is a lens array including a plurality of concave lenses regularly arranged along the Y direction. The plurality of concave lenses may be randomly arranged along the Y direction, or the curvature of each concave lens may deviate. The lens array 20a covers the light spot range of the light beam 10b incident on the lens array 20a. In embodiment 1, there is a restriction that the beam radius r on the lens 20a does not exceed the curvature radius R of the lens. In contrast, there is no such restriction in the third variant. This is because, even if the curvature radius R of each concave lens is smaller than the beam radius r of the light beam 10b, the plurality of concave lenses will cover the light spot range of the light beam 10b. Through the above, it can be achieved Figure 5B The diffusion angle θ2 of the light beam 10b in the dashed line portion is shown, so the diffusion angle θ2 can be further increased.

[0147] Figure 8C : is a diagram schematically showing the far-field intensity distribution of the light beam 10b emitted from the lens array and the single lens. The solid line and the dotted line respectively represent the intensity distribution of the light beam 10b emitted from the lens array and the single lens. In the case of the single lens, the intensity of the light beam 10b is approximately zero at both ends of the main lobe. In contrast, in the case of the lens array, the intensity of the light beam 10b at the above-mentioned two ends is higher, and the maximum intensity at the center of the light beam 10b is lower. In the lens array, as Figure 8B Each concave lens shown diffuses the incident light, so Figure 8C This can alleviate the unevenness of the intensity distribution, thereby irradiating a wider area in the Y direction with the low-intensity light beam 10b.

[0148] Figure 9 This is a perspective view schematically showing an example of an optical device 140 of the fourth variant of embodiment 1. The optical device 140 of the fourth variant is different from the optical device 130 of the third variant in that the lens 20a included in the optical element 20 includes a lens array of multiple concave lenses regularly arranged along the X direction and the Y direction. The multiple concave lenses can be randomly arranged along the Y direction, or the curvature of each concave lens can be deviated. The light beam 10b emitted from the light emitting surface 10s diffuses in both the X direction and the Y direction. Because of the reference Figure 8C For the reasons described above, a wider area in the X and Y directions can be irradiated with the low-intensity light beam 10 b.

[0149] The intensity of laser light is classified into each level according to JIS (Japanese Industrial Standard) C6802 "Safety Standards for Laser Products". From the perspective of eye safety, the intensity of laser light is preferably level 1. Even if the intensity distribution of the light beam 10b emitted from the light emitting surface 10s does not meet level 1, by using Figure 8A and Figure 9 The optical element 20 shown diffuses the light beam 10 b and can also make the intensity distribution of the light beam 10 b emitted from the optical element 20 satisfy level 1.

[0150] Figure 10A This is a perspective view schematically showing an example of an optical device 150 according to a fifth modified example of the first embodiment. Figure 10B It will Figure 10A The illustrated configuration is a diagram viewed along the +Y direction. Figure 10A and Figure 10B The dotted line shown is a line connecting the stop points of the concave lens 20a in the Y direction. The optical device 150 of the fifth variant is different from the optical device 100 of the first embodiment in that the curvature of the lens 20a in the Y direction included in the optical element 20 changes monotonically along the X direction. In this way, the optical element 20 has a portion where the curvature of the lens 20a in the Y direction changes along the X direction. Figure 10B As shown, if the emission angle of the light beam 10b is Increase to Then the passing distance of the light beam 10b in the lens 20a becomes longer. The curvature of the lens 20a for the light beam 10b at a certain emission angle can be known from the cut surface of the lens 20a when the lens 20a is cut with the following plane. This plane is a plane parallel to both the emission direction and the Y direction of the light beam 10b in the optical element 20. If the curvature of the lens 20a in the Y direction is constant along the X direction, the curvature of the lens 20a for the light beam 10b increases along with the emission angle of the light beam 10b. In contrast, in Figure 10BIn the example shown, by making the curvature of lens 20a in the Y direction monotonically decrease along the +X direction, the curvature of lens 20a for light beam 10b can be kept constant regardless of the emission angle. In the optical device 150 of the fifth modified example, the divergence angle θ2 of light beam 10b remains constant regardless of the emission angle of light beam 10b. The shape and intensity distribution of light beam 10b are independent of the emission angle of light beam 10b. Even if the curvature of lens 20a for light beam 10b is not strictly constant regardless of the emission angle, changes in the shape and intensity distribution of light beam 10b caused by changes in the emission angle can be suppressed.

[0151] In the fifth modification, the upper surface 20as1 of the optical element 20 is configured as a lens surface, and the curvature of the upper surface 20as1 varies along the X direction. However, the lower surface 20as2 of the optical element 20 may be configured as a lens surface, and the curvature of the lower surface 20as2 may vary along the X direction. In this case, the upper surface 20as1 may also be flat.

[0152] Figure 10C This is a perspective view schematically showing an example of an optical device 160 according to a sixth modified example of the first embodiment. Figure 10D It will Figure 10C The structure shown is a diagram observed along the +Y direction. As in the above-mentioned embodiment, the medium 20b may not be in contact with the light emitting surface 10s of the light deflecting device 10. The optical element 20 of the optical device 160 of the sixth variant has a portion where the curvature in the Y direction of the lens 20a is constant along the X direction. The optical device 160 of the sixth variant is different from the optical device 100 of embodiment 1 in that the upper surface 20as1 of the lens 20a, which is the light emitting side surface of the optical element 20 and the lens surface, is tilted along the X direction relative to the light emitting surface 10s of the deflecting device 10. That is, the distance between the light emitting surface 10s and the lens surface 20as1 along the direction perpendicular to the light emitting surface 10s is changed along the X direction. Figure 10D In FIG. 5 , it is assumed that the angle formed by the lens surface 20as1 and the light exit surface 10s when viewed in the X direction is δ.

[0153] If the curvature of the lens 20a is constant along the X direction, the focal length of the lens 20a is constant along the X direction. On the other hand, macroscopically, the light 10b from the light deflection element 10 can be regarded as being emitted from a sufficiently small point. If the emission angle of the light beam 10b is set to arrive If the angle δ changes between , the shape and intensity distribution of the light beam 10b will change depending on the emission angle. This is because, although the focal length of the lens 20a is constant, the optical path length from the emission point of the light beam 10b to the lens surface 20as1 changes. In the optical device 160 of the sixth modified example, the change in the optical path length can be suppressed. Here, the angle δ is most preferably equal to the middle of the emission angle range of the light beam 10b (i.e. ).

[0154] The following is a calculation example for explaining the effect of the sixth modification. Furthermore, let's assume that the optical path length from the emission point of the light deflection element 10 to the lens surface at an intermediate emission angle of 20° is 10 mm. When δ = 0°, the optical path length from the emission point to the lens surface in the direction perpendicular to the light emission surface 10s of the light deflection element 10 (i.e., the direction corresponding to an emission angle of 0°) is 10 × cos20° = 9.40 mm. At an emission angle of 5°, the optical path length is (10 × cos20°) / cos5° = 9.43 mm, and at an emission angle of 35°, the optical path length is (10 × cos20°) / cos35° = 11.47 mm. Therefore, the fluctuation range of the optical path length when the emission angle changes from 5° to 35° is 2.04 mm.

[0155] On the other hand, Figure 10C and Figure 10D In the configuration shown, when δ = (5° + 35°) / 2 = 20°, the optical path length at an emission angle of 5° is 10 × cos (20° - 5°) = 10.35 mm, and the optical path length at an emission angle of 35° is 10 × cos (20° - 35°) = 10.35 mm. Therefore, the fluctuation range of the optical path length is 0.35 mm. This shows that the fluctuation range can be suppressed to 17% compared to the case where δ = 0°.

[0156] Thus, in the optical device 160 of the sixth modification, the curvature of the lens 20a can be kept constant along the X direction while suppressing changes in the optical path length depending on the emission angle. As a result, changes in the shape and intensity distribution of the light beam 10b accompanying beam scanning can be suppressed.

[0157] In the sixth modification, the lower surface 20as2 of the optical element 20 is tilted in the X direction, but may be parallel to the light exit surface 10s of the light deflecting device 10. The light incident surface of the medium 20 is parallel to the light exit surface 10s, but may be tilted in the X direction.

[0158] In addition, the lens surface of the lens 20a may be formed on the lower surface 20as2 which is the incident side surface. Figure 10EThis is a perspective view schematically showing an example of an optical device 170 according to a seventh modification of the first embodiment. Figure 10F It will Figure 10E The structure shown is viewed along the +Y direction. The optical device 170 of the seventh modification example differs from the optical device 160 of the sixth modification example in that the distance between the light emitting surface 10s and the lower surface 20as2 of the optical element 20 in the direction perpendicular to the light emitting surface 10s is changed along the X direction.

[0159] In the seventh modification, the upper surface 20as1 of the optical element 20 is parallel to the light exit surface 10s of the light deflecting device 10, but may be tilted in the X direction. Furthermore, the light incident surface of the medium 20 is parallel to the light exit surface 10s, but may be tilted in the X direction.

[0160] (Implementation Method 2)

[0161] Next, refer to Figure 11 A basic configuration example of an optical device according to Embodiment 2 of the present disclosure will be described. Figure 11 : is a perspective view schematically showing an example of an optical device 200 according to Embodiment 2 of the present disclosure. Figure 11 In the embodiment 2, the optical device 200 includes a light deflecting device 30 and an optical element 20 .

[0162] The optical deflection device 30 of embodiment 2 includes a plurality of optical waveguides 30w and a plurality of phase shifters 30p connected to the plurality of optical waveguides 30w. The plurality of optical waveguides 30w are arranged along the X direction and extend along the Y direction. The number of the plurality of optical waveguides 30w can be, for example, greater than 8 and less than 64. Each of the plurality of optical waveguides 30w includes a light emission region 30r on its surface for emitting light. A grating 30g is provided in each of the plurality of light emission regions 30r. The optical waveguide 30w has a higher refractive index than an external medium such as air. The optical waveguide 30w propagates light along the Y direction by total internal reflection. Light propagating in the Y direction in the optical waveguide 30w is diffracted by the grating 30g and is emitted from the light emission region 30r to the outside as a plurality of diffracted lights parallel to the YZ plane. The length of the light emission region 30r in the Y direction can be, for example, greater than 1 μm and less than 10 μm. The number of concave portions of the grating 30g can be set, for example, to 4 or more and 16 or less. The length of the concave portions of each period of the grating 30g in the Y direction, i.e., the duty cycle, can also be appropriately varied by adjusting the depth and number of the concave portions of the grating. In the optical deflection device 30 of Embodiment 2, a light beam is formed by the interference of light emitted from the plurality of optical waveguides 30w. The light beam can also be said to be emitted from the light emission surface 30s, which includes the plurality of light emission areas 30r. The light beam has a shape extending in the Y direction due to the superposition of multiple diffracted light beams parallel to the YZ plane.

[0163] The multiple phase shifters 30p, like the multiple optical waveguides 30w, are arranged along the X direction and extend along the Y direction. The phase shifter 30p has a structure in which the refractive index changes according to the change of the applied driving voltage. In one example, the phase shifter 30p can be formed from a thermo-optical material whose refractive index changes with temperature. The phase shifter 30p has a heater (not shown) that changes the temperature of the thermo-optical material. The heater (not shown) is provided with two electrodes for applying the driving voltage. As another example, the phase shifter 30p can be formed from an electro-optical material whose refractive index changes with the change of the driving voltage. The phase shifter 30p is provided with two electrodes for applying the driving voltage to the electro-optical material. If the driving voltage changes due to the input of a control signal from a control circuit (not shown), the refractive index of the phase shifter 30p changes, and the phase of the light passing through the phase shifter 30p changes. In the optical deflection device 30 of Embodiment 2, the driving voltage changes in response to a control signal, causing the phase of light incident from the multiple phase shifters 30p to the multiple optical waveguides 30w to shift by a predetermined amount in the order in which the multiple optical waveguides 30w are arranged. This phase shift changes the emission direction of the light beam along the X direction.

[0164] Next, refer to Figure 12A and Figure 12B , a description will be given of a change in the emission direction of the light beam 30b emitted from the light emission surface 30s of the light deflecting device 30. Figure 12A and Figure 12B It will Figure 11 The structure shown is a diagram viewed along the +Y direction. Figure 12A and Figure 12B In the example shown, the light deflecting device 30 and the optical element 20 are in contact with each other and are arranged symmetrically with respect to a plane parallel to the YZ plane. Figure 12A and Figure 12B In the example shown, the emission angle of the light beam 30b is from Change to The light deflection device 30 according to the second embodiment is different from the light deflection device 10 according to the first embodiment. has a negative value, Has a positive value. The absolute value of In order to make the entire light beam 30b after passing through the optical element 20 be effectively emitted from the upper surface 20as1 of the lens 20a of the optical element 20 to the outside, the length L in the X direction of the optical element 20 is set to x Designed to be greater than the length d in the X direction of the light deflecting device 30 x Specifically, the length L of the optical element 20 is x According to the length d of the light deflecting device 30 x , the minimum emission angle of light beam 30b Maximum emission angle of light beam 30b and the height L of the optical element 20 in the Z direction z The light beam 30b is refracted by the upper surface 20as1 of the lens 20a and emitted to the outside.

[0165] Next, refer to Figure 13 The degree of diffusion of the light beam 30 b in the Y direction after passing through the optical element 20 will be described. Figure 13 It will Figure 11 The structure shown is a diagram viewed along the +X direction. Figure 4 As explained. Figure 13 As shown, the divergence angle θ2 of the light beam 30b is increased by the optical element 20. As the optical element 20 of the second embodiment, the optical elements 20 of the first to fifth modified examples of the first embodiment may be used.

[0166] In the optical device 200 of the second embodiment, the divergence angle θ2 of the light beam 30b can also be changed by providing the optical element 20 on the light deflection device 30. Therefore, the light beam 30b having a degree of divergence according to the intended use can be easily obtained.

[0167] (Implementation 3)

[0168] Next, refer to Figure 14 A basic configuration example of an optical device according to Embodiment 3 of the present disclosure will be described. Figure 14 : is a stereoscopic diagram schematically showing an example of an optical device 300 of embodiment 3 of the present disclosure. The optical device 300 of embodiment 3 is different from the optical device 100 of embodiment 1 in that the optical element 20 includes a mirror 20c instead of the lens 20a. The optical element 20 of embodiment 3 includes a mirror 20c and a medium 20b. The mirror 20c is a plano-convex mirror having an upper surface 20cs1 and a lower surface 20cs2. The mirror 20c has a flat surface on the upper surface 20as1 and has a curvature in the Y direction on the lower surface 20cs2. The lower surface 20cs2 of the mirror 20c is equivalent to a reflecting surface. The reflectivity of the reflecting surface can be, for example, 90% or more at the wavelength of the light beam 10b. The mirror 20c is a cylindrical mirror having a structure extending in the X direction. The curvature of the plano-convex mirror is equal to the curvature of the plano-concave lens of embodiment 1. As described above with respect to the medium 20b. Figure 14 In the example shown, the medium 20b is air. Figure 14 In the example shown, the direction in which the reflecting surface 20cs2 of the mirror 20c extends is parallel to the direction in which the light exit surface 10s of the light deflecting device 10 extends.

[0169] Figure 15A and Figure 15B They are Figure 14 The structure shown is a diagram viewed along the +Y direction and the +X direction. Figure 15A As shown, the light beam 10b emitted upward from the light deflecting device 10 is reflected downward by the mirror 20c. The shortest distance L between the reflecting surface 20cs2 of the mirror 20c and the light emitting surface 10s of the light deflecting device 10 is z It is more preferable to design it to satisfy the following conditions. The light beam 10b emitted and reflected by the reflection surface 20cs2 of the mirror 20c no longer enters the light exit surface 10s. This is because the re-entry causes a loss of the light beam 10b emitted to the outside. Figure 15B As shown, the degree of diffusion of light beam 10b reflected downward increases. The focal point F of the light reflected by mirror 20c is located above the lower surface 20cs2 of mirror 20c. As described above, when the plano-concave lens of embodiment 1 is replaced with a plano-convex mirror, although there is a difference in the transmission and reflection of light beam 10b, the degree of diffusion of light beam 10b is similarly increased.

[0170] (Variation of Embodiment 3)

[0171] Next, refer to 16A to 16B A modification of the optical device 300 according to the third embodiment will be described. Figure 16A This is a perspective view schematically showing an example of an optical device 310 according to a modified example of the third embodiment.

[0172] Figure 16B It will Figure 16A The structure shown is a diagram observed along the +Y direction. The optical device 310 of the modified example of embodiment 3 is different from the optical device 300 of embodiment 3 in that the direction in which the reflecting surface 20cs2 of the mirror 20c extends is not parallel to the direction in which the light emitting surface 10s of the light deflecting device 10 extends. In this way, the reflecting surface 20cs2 of the mirror 20c is inclined relative to the light emitting surface 10s of the light deflecting device 10. Therefore, the possibility of the light beam 10b reflected downward by the reflecting surface 20cs2 of the mirror 20c re-entering the light emitting surface 10s can be greatly reduced. Furthermore, as Figure 16B As shown, the shortest distance L between the reflecting surface 20cs2 of the mirror 20c and the light emitting surface 10s of the light deflecting device 10 can be made z If the shortest distance L z becomes shorter, then Figure 15B Compared to the example shown, the light beam 10b emitted from the light deflecting device 10 can be reflected by the mirror 20c before it is greatly diffused. Therefore, the size of the mirror 20c in the Y direction can be reduced.

[0173] In the optical device of the present disclosure, Figure 14 and Figure 16A As shown, the light exit surface 10s of the light deflecting device 10 faces the direction of the reflecting surface 20cs2 of the mirror 20c. The light beam 10b emitted from the light exit surface 10s of the light deflecting device 10 is incident on the reflecting surface 20cs2 of the mirror 20c.

[0174] In addition to the above examples, when the plano-convex lens of the first and second variants of embodiment 1 is replaced with a plano-concave mirror, although there is a difference in the transmission and reflection of the light beam 10b, the degree of diffusion of the light beam 10b is similarly expanded or reduced. Figure 8A and Figure 9 Mirror 20c may also be as shown. Figure 10A The portion shown has a curvature in the Y direction that varies along the X direction.

[0175] Industrial Applicability

[0176] The optical device according to the embodiment of the present disclosure can be used for, for example, measuring the distance to an object.

[0177] Description of labels

[0178] 10 Light deflection device

[0179] 10L Light

[0180] 10b beam

[0181] 10e electrode

[0182] 10m1 Mirror 1

[0183] 10m2 Mirror 2

[0184] 10s light exit surface

[0185] 10w optical waveguide layer

[0186] 20 Optical Elements

[0187] 20a lens

[0188] 20as1 Upper surface of the lens

[0189] 20as2 Lower surface of lens

[0190] 20b medium

[0191] 20c mirror

[0192] 20cs1 Upper surface of the mirror

[0193] 20cs2 bottom surface of the mirror

[0194] 30 Light deflection device

[0195] 30b beam

[0196] 30g grating

[0197] 30p Phase Shifter

[0198] 30r Light emission area

[0199] 30s light exit surface

[0200] 30w optical waveguide

[0201] 100, 110, 120, 130, 140, 150, 200, 300, 310 optical devices

Claims

1. An optical device, wherein: have: a light deflecting device configured to emit a light beam having a shape extending in the second direction from a light emitting surface parallel to a first direction and a second direction intersecting the first direction toward a direction intersecting the light emitting surface, and configured to change the emitting direction of the light beam along the first direction; and an optical element disposed on the path of the light beam and configured to change the degree of diffusion of the light beam in the second direction; The optical element has a first surface on which the light beam is incident and a second surface on which the light beam is emitted; A distance between the light exit surface and the first surface or the second surface of the optical element along a direction perpendicular to the light exit surface changes along the first direction.

2. The optical device according to claim 1, wherein The optical element includes at least one lens having curvature in the second direction.

3. The optical device according to claim 2, wherein: The above-mentioned lens is a concave lens.

4. The optical device according to claim 2, wherein: The above-mentioned lens is a convex lens.

5. The optical device according to any one of claims 2 to 4, wherein: The optical element includes a portion where the curvature of the lens changes along the first direction.

6. The optical device according to any one of claims 1 to 4, wherein: The optical element is in contact with the light emitting surface of the light deflecting device.

7. The optical device according to claim 1, wherein The optical element includes at least one mirror having a curvature in the second direction; The mirror reflects the light beam emitted from the light exit surface of the light deflecting device.

8. The optical device according to claim 7, wherein: The above mirror is a convex mirror.

9. The optical device according to claim 7, wherein: The above-mentioned mirror is a concave mirror.

10. The optical device according to any one of claims 7 to 9, wherein: The optical element includes a portion where the curvature of the mirror changes along the first direction.

11. The optical device according to any one of claims 1 to 4, wherein: The light deflecting device includes: The first mirror and the second mirror are opposed to each other and extend in the first direction; and The optical waveguide layer is located between the first mirror and the second mirror and propagates light in the first direction.

12. The optical device according to any one of claims 1 to 4, wherein: The light deflecting device includes: a plurality of optical waveguides arranged along the first direction and extending along the second direction; and A plurality of phase shifters are connected to the plurality of optical waveguides respectively.

13. The optical device according to claim 12, wherein: A grating is provided on each of the plurality of optical waveguides, and the light beam is emitted through the grating.

14. The optical device according to claim 1, wherein The optical element includes at least one lens having a curvature in the second direction, and the curvature of the lens is constant in a portion along the first direction; The first surface or the second surface in the portion of the optical element is inclined along the first direction relative to the light exit surface.

Images