Angle amplifier, transmitting system and design method of angle amplifier

Abstract

The present invention provides an angle amplifier, a transmitting system and a design method of the angle amplifier, wherein the angle amplifier comprises: a plurality of amplifying units, each of which corresponds to a phase distribution, the phase distribution indicating the corresponding relationship between the incident angle of a light beam incident on the amplifying unit and the phase modulated by the amplifying unit; the amplifying unit can modulate a light beam incident at a first angle to emit at a second angle, the first angle is smaller than the second angle, and the second angle is smaller than 90 degrees. By using the angle amplifier, the scanning angle of a MEMS galvanometer laser radar can be directly enlarged, avoiding the situation of splicing multiple MEMS galvanometer laser radars, not only making the overall volume smaller and lighter, but also reducing the cost.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and in particular to an angle amplifier, a transmitting system and a design method of the angle amplifier. Background Art

[0002] The scanning angle of existing MEMS (Micro-Electro-Mechanical System) galvanometer laser radar is usually within 40°, and its scanning angle is small. A single MEMS galvanometer laser radar cannot scan at a larger angle. When the scanning angle needs to be expanded, multiple MEMS galvanometer laser radars are usually required to be spliced ​​together to achieve large-angle scanning. This method greatly increases the number of laser radars and also increases the cost of using laser radars, resulting in it being unable to meet the market's increasingly stringent requirements for laser radars, such as more miniaturization, lightweight, simplicity and low cost. Summary of the invention

[0003] In order to solve the above problems, an object of the embodiments of the present invention is to provide an angle amplifier, a transmitting system and a design method of the angle amplifier.

[0004] In the first aspect, an embodiment of the present invention provides an angle amplifier, comprising: a plurality of amplifying units, each of the amplifying units corresponding to a phase distribution, the phase distribution representing the correspondence between the incident angle of a light beam incident into the amplifying unit and the phase that can be modulated by the amplifying unit; the amplifying unit can modulate a light beam incident at a first angle to be emitted at a second angle, the first angle being smaller than the second angle, and the second angle being smaller than 90 degrees.

[0005] Optionally, multiple amplifying units are arranged in parallel along the x-direction; the angle amplifier is a metasurface, and the angle amplifier also includes a first substrate for growing multiple amplifying units; the amplifying unit includes multiple identical first nanostructures arranged perpendicular to the x-direction, and the first nanostructures with the same x-coordinate correspond to the same phase distribution; the first nanostructure can modulate a light beam incident at a first angle to be emitted at a second angle.

[0006] Optionally, the phase distribution of the first nanostructure satisfies in, represents a phase distribution corresponding to each first nanostructure in the amplification unit corresponding to the x position of the first substrate; represents a constant phase; x represents the position of each first nanostructure in the amplification unit in the x direction; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number and no represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

[0007] Optionally, the plurality of amplifying units are arranged in an array; the angle amplifier is a metasurface, the angle amplifier further comprises a second substrate for growing the plurality of amplifying units, and the second substrate is located in an xoy plane; each of the amplifying units comprises at least one second nanostructure; the phase distribution of the second nanostructure satisfies in, represents the phase distribution of the second nanostructure corresponding to the (x, y) coordinate position of the second substrate; the plane where the incident light beam is located is taken as the xoz plane, the plane where the angle amplifier is located is taken as the xoy plane, and the yoz plane is a plane perpendicular to the plane where the incident light beam is located and the plane where the angle amplifier is located; φ2 represents the angle between the projection of the light beam emitted at the second angle on the yoz plane and the z-axis; represents a constant phase; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number and n o represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

[0008] Optionally, the relationship between the second angle and the first angle satisfies: a multiple relationship, a nonlinear relationship or a trigonometric function relationship.

[0009] Optionally, the first substrate is transparent in the working band, and the first nanostructure in the amplifying unit can transmit the light beam incident at the first angle at the second angle.

[0010] Optionally, the angle amplifier further comprises a reflection layer, wherein the reflection layer is arranged between the first substrate and the amplification unit; the reflection layer is capable of reflecting the light beam incident on the surface of the reflection layer (13).

[0011] Optionally, the angle magnifier is a multi-layer diffractive optical element or a Fresnel lens.

[0012] In the second aspect, an embodiment of the present invention further provides an emission system, comprising any of the above-mentioned angle amplifiers, MEMS galvanometers and light sources; the MEMS galvanometer is arranged on the light-emitting side of the light source, and is used to direct the light beam emitted by the light source into the angle amplifier at a first angle and scan along the x direction; the angle amplifier is arranged on the light-emitting side of the MEMS galvanometer, and is used to modulate the light beam incident at the first angle to be emitted at a second angle.

[0013] Optionally, the light source comprises a vertical cavity laser.

[0014] Optionally, the light beam emitted by the light source includes a single collimated laser beam; or, an array of multiple linearly arranged laser beams.

[0015] Optionally, when the light beam emitted by the light source is a single collimated laser beam, the MEMS galvanometer realizes two-dimensional scanning; when the light beam emitted by the light source is a laser array of multiple beams arranged perpendicular to the x-direction, the MEMS galvanometer realizes one-dimensional scanning.

[0016] In the third aspect, an embodiment of the present invention also provides a design method for an angle amplifier, including: determining the operating wavelength of the angle amplifier; determining the relationship between the first angle of the light beam and the second angle of the light beam after it is emitted from the angle amplifier; determining the phase distribution of the nanostructure corresponding to each amplification unit in the angle amplifier; and selecting data of the nanostructure corresponding to the phase distribution in a nanostructure database to generate the angle amplifier.

[0017] In the solution provided in the first aspect of the embodiment of the present invention, the angle amplifier can modulate the light beam incident therein at a smaller angle into a light beam emitted at a larger angle (but not exceeding 90 degrees) based on the multiple amplification units it has, so as to achieve angle expansion. By using the angle amplifier, the scanning angle of the MEMS galvanometer laser radar can be directly expanded, avoiding the situation of splicing multiple MEMS galvanometer laser radars to expand the scanning angle, which not only makes the volume of the MEMS galvanometer laser radar that can achieve a large scanning angle more compact and lightweight, but also reduces the cost.

[0018] In the solution provided in the second aspect of the embodiment of the present invention, by adding an angle amplifier on the light-emitting side of the MEMS galvanometer, the angle of the light beam reflected by the MEMS galvanometer can be expanded, that is, the scanning range of the transmitting system in the scanning area can be expanded. The purpose of beam expansion can be achieved without using multiple transmitting systems with MEMS galvanometers, thereby reducing costs and the overall volume of the transmitting system.

[0019] In the solution provided in the third aspect of the embodiment of the present invention, the phase distribution corresponding to the nanostructures at different positions can be directly calculated by a mathematical relationship only according to the working wavelength of the angle amplifier and the relationship between the first angle and the second angle, and the data of the corresponding nanostructures can be directly found in the nanostructure database to finally generate the angle amplifier. This method can be used to determine the phase distribution of the nanostructure more concisely and clearly, and quickly and accurately generate an angle amplifier that can expand the incident light beam to a certain angle.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A top view of an angle amplifier provided by an embodiment of the present invention is shown;

[0023] Figure 2 A front view of an angle amplifier provided by an embodiment of the present invention is shown;

[0024] Figure 3 A front view of an angle amplifier for a metasurface provided by an embodiment of the present invention is shown;

[0025] Figure 4 A top view of an angle amplifier of a metasurface provided by an embodiment of the present invention is shown;

[0026] Figure 5 A schematic diagram of a reflective angle amplifier provided by an embodiment of the present invention is shown;

[0027] Figure 6 A schematic diagram showing the derivation principle of the first nanostructure phase distribution in the transmission angle amplifier provided in an embodiment of the present invention is shown;

[0028] Figure 7 A top view of another metasurface angle amplifier provided by an embodiment of the present invention is shown;

[0029] Figure 8 A schematic diagram showing the derivation principle of the second nanostructure phase distribution in another metasurface angle amplifier provided by an embodiment of the present invention is shown;

[0030] Fig. 9 A schematic diagram of a transmission system using an angle amplifier capable of achieving transmission in a transmission system provided by an embodiment of the present invention is shown;

[0031] Fig.10 A schematic diagram of a transmitting system using an angle amplifier capable of achieving reflection in a transmitting system provided by an embodiment of the present invention is shown;

[0032] Fig.11 A flow chart showing a method for designing an angle amplifier provided by an embodiment of the present invention is shown;

[0033] Fig.12 A relationship diagram between the first angle and the phase distribution corresponding to the first embodiment in the design method of the angle amplifier provided by the embodiment of the present invention is shown;

[0034] Fig.13 The figure shows the relationship between the first angle and the phase distribution corresponding to the second embodiment in the design method of the angle amplifier provided in the embodiment of the present invention.

[0035] icon:

[0036] 1-angle amplifier, 11-amplification unit, 111-first nanostructure, 12-first substrate, 13-reflection layer, 14-second substrate, 2-MEMS galvanometer, 3-light source. DETAILED DESCRIPTION

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The embodiment of the present invention provides an angle amplifier, see Figure 1As shown, the angle amplifier comprises: a plurality of amplifying units 11, each amplifying unit 11 corresponds to a phase distribution, and the phase distribution represents the corresponding relationship between the incident angle of the light beam incident into the amplifying unit 11 and the phase that can be modulated by the amplifying unit 11; Figure 1 This is a top view of the amplifier at this angle.

[0041] like Figure 2 As shown, the amplifying unit 11 can modulate a light beam incident at a first angle to be emitted at a second angle, the first angle is smaller than the second angle, and the second angle is smaller than 90 degrees; Figure 2 is the main view of the angle magnifier, and Figure 2 In the figure, the lower side of the angle amplifier is the light incident side, and the upper side of the angle amplifier is the light exiting side; accordingly, the first angle is θ1, and the second angle is θ2.

[0042] In the angle amplifier provided in the embodiment of the present invention, each amplifying unit 11 may be of any structure, for example, it may be of a square structure, a circular structure, or it may also be of a long strip structure, which is not limited in the embodiment of the present invention. Figure 1 As shown, Figure 1 The top view of the angle amplifier in which the amplifying unit 11 is a strip-shaped structure is shown; wherein each amplifying unit 11 corresponds to a phase distribution, and different amplifying units 11 may correspond to different phase distributions; the phase distribution is used to represent a corresponding relationship, that is, the corresponding relationship between the incident angle of the light beam incident on the amplifying unit 11 and the phase that can be modulated by the amplifying unit 11. In other words, each amplifying unit 11 has the function of modulating the phase of the light beam incident therein with a first angle so that the light beam is emitted at a second angle; and the second angle (exit angle) corresponding to the light beam modulated by the amplifying unit 11 is greater than the first angle (incident angle) corresponding to the light beam incident on the amplifying unit 11, that is, the angle amplifier has a relationship that the exit angle is greater than the incident angle; in addition, in order to avoid the total reflection effect, the second angle should be less than 90 degrees. Optionally, in an embodiment of the present invention, the angle amplifier may be an optical device such as a multilevel diffractive optical element (MDOEs) or a Fresnel lens (FL).

[0043] The angle amplifier provided in the embodiment of the present invention can modulate a light beam incident therein at a smaller angle into a light beam emitted at a larger angle (but not exceeding 90 degrees) based on the multiple amplification units 11 it possesses, so as to achieve angle expansion. By using the angle amplifier, the scanning angle of the MEMS galvanometer laser radar can be directly expanded, avoiding the situation of splicing multiple MEMS galvanometer laser radars to expand the scanning angle, which not only makes the volume of the MEMS galvanometer laser radar capable of achieving a large scanning angle smaller and lighter, but also reduces the cost.

[0044] Alternatively, see Figure 1 As shown, the multiple amplifying units 11 are arranged in parallel along the x direction; wherein the multiple amplifying units 11 are arranged in parallel along the x direction, and the x direction is a direction set for convenient placement of the amplifying units 11. In order to facilitate the description of the placement of the multiple amplifying units 11 in the embodiment of the present invention, the amplifying units 11 can be arranged in parallel along the x direction. Figure 1 The horizontal rightward direction shown is the x direction. Accordingly, the main view of the angle amplifier can be seen in Figure 2 shown.

[0045] See also Figure 3 As shown, the angle amplifier is a metasurface, and the angle amplifier also includes a first substrate 12 for growing a plurality of amplifying units 11; for example, the plurality of amplifying units 11 can be grown on the same side of the first substrate 12 along the x direction, as shown in FIG. Figure 3 The upper side of the first substrate 12 is the light emitting side of the angle amplifier.

[0046] See also Figure 4 As shown, Figure 4 Each amplifying unit 11 includes a plurality of identical first nanostructures 111 arranged perpendicular to the x-direction, and the first nanostructures 111 with the same x-coordinate correspond to the same phase distribution; the first nanostructures 111 can modulate a light beam incident at a first angle to be emitted at a second angle.

[0047] In the metasurface angle amplifier provided in the embodiment of the present invention, Figure 4As shown, the first nanostructures 111 included in each amplifying unit 11 can be arranged one by one along a direction perpendicular to the x-direction on one side of the first substrate 12; and the multiple first nanostructures 111 included in each amplifying unit 11 have the same phase distribution. In other words, any first nanostructures 111 in the same amplifying unit 11 have the same structure and can modulate a light beam incident therein at a first angle to be emitted at a second angle greater than the first angle and less than 90 degrees. For example, the angle amplifier is a metasurface. If the phase distribution corresponding to each first nanostructure 111 in a certain amplifying unit 11 on the angle amplifier is capable of modulating the incident angle (such as the first angle: 15 degrees) of the light beam incident on each first nanostructure 111 to a distribution emitted at a certain exit angle (such as the second angle: 30 degrees), then when the incident angle (first angle) of the light beam incident on the amplifying unit 11 on the angle amplifier is 15 degrees, that is, when the incident angle (first angle) of the light beam incident on each first nanostructure 111 in the amplifying unit 11 is 15 degrees, each first nanostructure 111 in the amplifying unit 11 can emit the light beam at 30 degrees (second angle) to achieve the purpose of amplifying the incident angle of the incident light.

[0048] Since the angle amplifier used in the embodiment of the present invention is a metasurface, the angle amplifier has the advantages of light weight, thin overall thickness, simple system, lower price and high production capacity.

[0049] Optionally, the first substrate 12 is transparent in the working band, and the first nanostructure 111 in the amplifying unit 11 can transmit the light beam incident at the first angle at the second angle.

[0050] In the embodiment of the present invention, the first substrate 12 is a transparent structural layer in the working band, that is, the first substrate 12 has a high transmittance to the light in the working band, wherein the working band of the first substrate 12 is the working band corresponding to the light beam required to be modulated by the angle amplifier, for example, if the light beam is infrared light, then the working band corresponding to the light beam that can be modulated by the angle amplifier includes the band corresponding to infrared light. Figure 3 As shown, when the first substrate 12 is transparent in the working wavelength band, the angle amplifier is a transmission angle amplifier, which can transmit the light beam incident therein at a first angle (such as Figure 3 The light beam incident from the lower side of the first substrate 12 at the first angle θ1 is emitted at the second angle ( Figure 3 As shown, the light is emitted from the upper side of the first substrate 12 at a second angle θ2).

[0051] Alternatively, if Figure 5As shown, the angle amplifier which is a metasurface further includes a reflection layer 13, which is arranged between the first substrate 12 and the amplification unit 11; the reflection layer 13 can reflect the light beam incident on the surface of the reflection layer 13.

[0052] In the embodiment of the present invention, a reflective layer 13 may be first grown on one side of the first substrate 12, and then a plurality of amplifying units 11 may be grown on the side of the reflective layer 13 away from the first substrate 12, so as to obtain a reflective angle amplifier capable of reflecting incident light. Figure 5 As shown, the reflective angle amplifier can transmit the light beam (such as Figure 5 The light beam incident on the reflective layer 13 at the first angle θ1 from the side away from the first substrate 12 is reflected at the second angle (e.g. Figure 5 As shown, the light is emitted from the surface of the reflective layer 13 toward a side θ2 away from the first substrate 12).

[0053] The transmissive angle amplifier and the reflective angle amplifier respectively provided in the embodiments of the present invention can be selected and used according to different installation environments and actual needs, and the application scenarios of the angle amplifier are more extensive.

[0054] Optionally, the phase distribution of the first nanostructure 111 satisfies in, represents the phase distribution corresponding to each first nanostructure 111 in the amplifying unit 11 corresponding to the x position of the first substrate 12; represents a constant phase; x represents the position of each first nanostructure 111 in the amplification unit 11 in the x direction; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number and n o represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

[0055] In the embodiment of the present invention, if the phase distribution of each first nanostructure 111 corresponding to different amplifying units 11 is to be determined (i.e., the phase distribution of each amplifying unit 11), corresponding calculations can be performed based on the specific position of the first nanostructure 111 in the x direction, the incident angle of the light beam entering it, and the exit angle of the light beam exiting the first nanostructure 111. The embodiment of the present invention takes a transmissive angle amplifier as an example to describe in detail how to use a mathematical relationship to accurately determine the phase distribution of each first nanostructure 111, which is also applicable to a reflective angle amplifier and will not be described in detail in this embodiment. See Figure 6As shown, when two light beams simultaneously enter the angle amplifier at a first angle θ1, the distance between the two incident light beams is Δx; by calculating the optical path difference between the two light beams, that is, Δl = Δx (sinθ2-sinθ1), the phase difference between the two can be determined When Δx approaches 0, we can get the mathematical relationship: Specifically, the mathematical relationship can express that each first nanostructure 111 in the amplifying unit 11 corresponding to position x is a nanostructure that can modulate a light beam incident therein at a first angle θ1 (and the wave number of the light beam is k) into a nanostructure emitted at a second angle θ2.

[0056] Furthermore, by integrating the mathematical relationship, we can get the formula: According to this formula, the phase distribution of each first nanostructure 111 that can achieve the above modulation effect can be determined. In the formula, x is used to represent the phase distribution to be determined The specific position of the first nanostructure 111 in the x direction; θ1 is used to represent the incident angle of the light beam incident on the first nanostructure 111, and θ2 is used to represent the exit angle of the light beam emitted from the first nanostructure 111; the wave number That is, the wave number k is determined by the refractive index n of the spatial medium corresponding to the angle amplifier. o The wavelength λ of the light beam is determined by the refractive index n of the spatial medium corresponding to the angle amplifier. o It can be the refractive index of the spatial medium corresponding to the light beam emitted by the angle amplifier; is used to represent a constant phase, which can be any value, such as 0, π, 2π, 3π, etc. By calculating this formula, the phase distribution of the first nanostructure 111 that can achieve the above modulation effect (i.e., modulate the light beam incident therein at the first angle θ1 to be emitted at the second angle θ2) can be determined.

[0057] The embodiment of the present invention can more accurately determine the phase distribution corresponding to the first nanostructure 111 at each position, and the angle amplifier can arrange the first nanostructures 111 with different phase distributions at different positions in the x-direction according to actual needs, so that the obtained angle amplifier is an angle amplifier that can achieve one-dimensional amplification.

[0058] Alternatively, see Figure 7 As shown, multiple amplifying units 11 are arranged in an array; the angle amplifier is a metasurface, and the angle amplifier also includes a second substrate 14 for growing multiple amplifying units 11, and the second substrate 14 is located in the xoy plane; each amplifying unit 11 includes at least one second nanostructure.

[0059] In the metasurface angle amplifier provided in the embodiment of the present invention, Figure 7 As shown, Figure 7 FIG. 1 is a top view of an angle amplifier in which a plurality of amplifying units 11 are arranged in an array. The amplifying units 11 arranged in an array are disposed on the same side of the second substrate 14; see Figure 8 As shown, the second substrate 14 is located in the xoy plane in the xyz coordinate system, and at least one second nanostructure included in each amplification unit 11 has the same phase distribution. For example, on one side surface of the second substrate 14 located on the xoy plane (such as Figure 8 The upper surface of the second substrate 14 in the angle amplifier is formed by arranging a plurality of amplifying units 11 in an array, and each amplifying unit 11 has a second nanostructure. Since each amplifying unit 11 in the angle amplifier corresponds to a phase distribution, and the second nanostructures in the same amplifying unit 11 can correspond to the same phase distribution, the second nanostructures included in different amplifying units 11 can correspond to different phase distributions than the second nanostructures in other amplifying units 11. For example, if each amplifying unit 11 includes a second nanostructure, these second nanostructures correspond to a phase distribution.

[0060] Among them, the phase distribution of the second nanostructure satisfies in, represents the phase distribution of the second nanostructure corresponding to the (x, y) coordinate position of the second substrate 14; the plane where the incident light beam is located is taken as the xoz plane, the plane where the angle amplifier is located is taken as the xoy plane, and the yoz plane is a plane perpendicular to the plane where the incident light beam is located and the plane where the angle amplifier is located; φ2 represents the angle between the projection of the light beam emitted at the second angle on the yoz plane and the z-axis; represents the constant phase; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number and n o represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

[0061] See also Figure 8 As shown, Figure 8Schematic diagram of the setting and optical path of the angle amplifier in the xyz coordinate system. In the embodiment of the present invention, if the phase distribution of at least one second nanostructure corresponding to different amplifying units 11 is to be determined (for example, the phase distribution of each amplifying unit 11), corresponding calculations can be performed based on the specific position of the second nanostructure to be determined on the xoy plane in the xyz coordinate system (such as (x, y) coordinates), the incident angle of the light beam incident therein (the angle of the incident light beam relative to the yoz plane in the xyz coordinate system), and the exit angle of the light beam emitted from the second nanostructure (the angle of the emitted light beam relative to the yoz plane in the xyz coordinate system).

[0062] The embodiment of the present invention takes a transmission-type angle amplifier as an example to describe in detail how to use a mathematical relationship to accurately determine the phase distribution of each second nanostructure. This is also applicable to a reflection-type angle amplifier, and will not be described in detail in this embodiment. Figure 8 As shown, in the xyz coordinate system, the incident light beam is emitted from the xoz plane (incident plane) to the angle amplifier (second nanostructure) located in the xoy plane, and is transmitted out through the angle amplifier after phase modulation. In the embodiment of the present invention, since the phase distribution of the second nanostructure satisfies the generalized Fresnel law, the inventors have found that the phase distribution calculation formula of the second nanostructure can be obtained by integrating the generalized Fresnel law: Where (x, y) is used to indicate the phase distribution to be determined. θ1 is used to represent the specific position of the second nanostructure on the xoy plane (i.e., the coordinates of the second nanostructure on the angle amplifier); θ1 is used to represent the incident angle of the light beam incident on the second nanostructure, wherein the incident angle can be expressed in space as: the angle between the projection of the incident light beam on the yoz plane and the incident light beam, and the yoz plane is a plane perpendicular to the incident plane (xoz plane), Figure 8 The projection of the incident light on the yoz plane coincides with the z-axis; θ2 is used to represent the exit angle of the light beam emitted from the second nanostructure, wherein the exit angle can be expressed in space as: the angle between the projection of the exit light beam on the yoz plane and the exit light beam, and the yoz plane is a plane perpendicular to the incident plane (xoz plane), Figure 8 The projection of the outgoing light on the yoz plane is shown by a dotted line; φ2 is the angle between the projection of the outgoing light beam on the yoz plane and the z-axis; the wave number That is, the wave number k is determined by the refractive index n of the spatial medium corresponding to the angle amplifier. o The wavelength λ of the light beam is determined by the refractive index n of the spatial medium corresponding to the angle amplifier. oIt can be the refractive index of the spatial medium corresponding to the light beam emitted by the angle amplifier; It is used to represent the constant phase, which can be any value, such as 0, π, 2π, 3π, etc. By calculating this formula, the phase distribution of the second nanostructure that can achieve the above modulation effect (i.e., modulate the light beam incident at the first angle θ1 to be emitted at the second angle θ2) can be determined.

[0063] The embodiment of the present invention can determine the phase distribution corresponding to the second nanostructure at each position, so that the angle amplifier is an optical element that can achieve two-dimensional angle magnification in space.

[0064] Optionally, the relationship between the second angle and the first angle satisfies: a multiple relationship, a nonlinear relationship or a trigonometric function relationship.

[0065] Among them, between the first angle of the light beam incident on the first nanostructure 111 and the second angle of the light beam emitted from the first nanostructure 111, in addition to the relationship that the second angle is greater than the first angle and the second angle is less than 90 degrees, the relationship that can be satisfied may also include: a multiple relationship, a nonlinear relationship, or a trigonometric function relationship. Among them, the multiple relationship may be that the size of the second angle is a times the size of the first angle, that is, θ2=aθ1, and a>1, for example, the size of the second angle is 2 times or 3 times the size of the first angle, etc.; the nonlinear relationship may be that the size of the second angle is the square or cube of the size of the first angle, etc., for example, when the first angle is greater than 1, θ2=θ1 2 etc.; the trigonometric function relationship may be that the second angle and the first angle form a certain sine function relationship, cosine function relationship or tangent function relationship, for example, sinθ2=1.5sinθ1, etc.

[0066] For example, in the embodiment of the present invention, when it is clear that each first nanostructure 111 in the amplifying unit 11 corresponding to a certain position (such as position x) is a nanostructure that can modulate a light beam incident therein at a first angle θ1 to be emitted at a second angle θ2 that is twice the size of the first angle, that is, the first angle and the second angle corresponding to the first nanostructure 111 simultaneously satisfy the relationship: And when θ2=2θ1, the phase distribution of each first nanostructure 111 that can achieve the above modulation effect can be determined according to these two formulas.

[0067] The embodiments of the present invention clarify the modulation effect that can be achieved by each first nanostructure 111, establish multiple relationships that should be satisfied between the first angle of the light beam entering the first nanostructure 111 and the second angle of the light beam emitting from the first nanostructure 111, and obtain the phase distribution corresponding to the first nanostructure 111 by means of integral operation. The angle amplifier can meet the needs of more practical application scenarios.

[0068] The embodiment of the present invention also provides a transmitting system, see Fig. 9 As shown, it includes: any of the above angle amplifiers 1, a MEMS galvanometer 2 and a light source 3; Fig. 9 A plurality of parallel solid lines represent the light beams emitted by the light source 3, and Fig. 9 Schematic diagram of a transmission system using an angle amplifier 1 capable of achieving transmission.

[0069] like Fig. 9 As shown, the MEMS galvanometer 2 is arranged on the light-emitting side of the light source 3, and is used to direct the light beam emitted by the light source 3 into the angle amplifier 1 at a first angle and scan along the x direction; the angle amplifier 1 is arranged on the light-emitting side of the MEMS galvanometer 2, and is used to modulate the light beam incident at the first angle to be emitted at a second angle.

[0070] In the embodiment of the present invention, the MEMS galvanometer 2 can reflect the light beam emitted by the light source 3, and the light beam reflected by the MEMS galvanometer 2 can be incident on the angle amplifier 1 at a first angle, and according to whether the angle amplifier 1 is a transmission type or a reflection type angle amplifier, the light beam incident on the angle amplifier 1 can be transmitted or reflected at a second angle. Fig. 9 As shown, after the light beam reflected by the MEMS galvanometer 2 enters the angle amplifier 1 (transmission type) at a first angle, the angle amplifier 1 can transmit the light beam to the scanning area at a second angle. Fig. 9 The scanning area is represented by a parallelogram area; it should be noted that the light beam transmitted to the scanning area by the angle amplifier 1 is scanned along the x direction based on the rotation of the MEMS galvanometer 2, that is, the scanning direction of the light beam transmitted by the angle amplifier 1 is determined by the MEMS galvanometer 2. Similarly, the case of selecting an angle amplifier capable of reflection for use in a transmitting system can be referred to Fig.10 As shown, the principle of scanning along the x direction is the same as the scanning principle of the above-mentioned transmission-type angle amplifier used in the transmission system, which will not be repeated here.

[0071] In the transmitting system provided in the embodiment of the present invention, by adding an angle amplifier 1 to the light-emitting side of the MEMS galvanometer 2, the angle of the light beam reflected by the MEMS galvanometer 2 can be expanded, that is, the scanning range of the transmitting system in the scanning area can be expanded. The purpose of beam expansion can be achieved without using multiple transmitting systems with MEMS galvanometers 2, thereby reducing costs and reducing the overall volume of the transmitting system.

[0072] Optionally, the light source 3 includes a vertical cavity laser, that is, the light beam emitted by the light source 3 is a laser beam. The vertical cavity laser is a semiconductor laser, and the laser emitted by the vertical cavity laser is emitted perpendicular to the top surface of the integrated circuit, and the use of a vertical cavity laser as the light source 3 has many advantages over the traditional use of an edge-emitting laser as a light source. For example, when the vertical cavity laser is used as the light source 3, the light emission direction is perpendicular to the substrate, and the integration of a high-density array can be easily realized, and a higher power output can be achieved, so that the light source 3 used in the embodiment of the present invention has a better light emission effect.

[0073] Optionally, the light beam emitted by the light source 3 includes a single collimated laser beam; or an array of multiple linearly arranged laser beams.

[0074] In the emission system provided by the embodiment of the present invention, the laser emitted by the light source 3 can be a collimated laser beam; or, it can also be a multi-beam laser array arranged in a linear manner and pre-set according to a certain emission angle, and the beam array reflected by the MEMS galvanometer 2 to the angle amplifier 1 is arranged perpendicular to the x direction. Optionally, in the case where the light beam emitted by the light source 3 is a single collimated laser beam, the MEMS galvanometer 2 realizes two-dimensional scanning, that is, it can realize the depth information measurement of three-dimensional space through two-dimensional scanning on the basis of single-point ranging (such as scanning the "surface" with a "point"); in the case where the light beam emitted by the light source 3 is a multi-beam linearly arranged laser array, and the beam array reflected by the MEMS galvanometer 2 to the angle amplifier 1 is arranged perpendicular to the x direction, the MEMS galvanometer 2 realizes one-dimensional scanning, that is, the multi-beam laser array emitted by the angle amplifier 1 and arranged linearly perpendicular to the x direction can be uniformly reciprocated and scanned along the x direction on the scanning area (such as scanning the "surface" with a "line").

[0075] In the emission system provided in the embodiment of the present invention, the light source 3 can be set to emit in different forms of single beam or multi-beam array according to actual needs, and the emission system can select the MEMS galvanometer 2 with different scanning forms corresponding to the form of the light beam emitted by the light source 3 to achieve better scanning and obtain more accurate scanning results.

[0076] The angle amplifier and the transmitting system including the angle amplifier are introduced in detail above, wherein the angle amplifier can be obtained by the following design method, and the design method of the angle amplifier is introduced in detail below.

[0077] The embodiment of the present invention provides a design method for an angle amplifier of a metasurface, see Fig.11 As shown, the method includes the following steps 101-104.

[0078] Step 101: Determine the operating wavelength of the angle amplifier.

[0079] The working wavelength of the angle amplifier is the wavelength of the light beam that can be modulated by the angle amplifier. For example, the wavelength range corresponding to the light beam incident on the angle amplifier includes the wavelength that can be modulated by the angle amplifier, so that the light beam corresponding to the wavelength can be modulated by the angle amplifier. When generating the angle amplifier, the embodiment of the present invention needs to determine the working wavelength of the angle amplifier according to the wavelength of the light beam incident on the angle amplifier.

[0080] Step 102: Determine the relationship between the first angle of the light beam and the second angle of the light beam after it is emitted from the angle amplifier.

[0081] In an embodiment of the present invention, the relationship between the first angle of the light beam entering the angle amplifier and the second angle of the light beam exiting the angle amplifier can be determined according to the modulation effect actually required by the angle amplifier. For example, the second angle is greater than the first angle, or the two are in a multiple relationship.

[0082] Step 103: Determine the phase distribution of the nanostructure corresponding to each amplification unit in the angle amplifier.

[0083] In the embodiment of the present invention, the phase distribution of the nanostructure corresponding to each amplification unit in the angle amplifier can be calculated based on the relationship between the second angle and the first angle determined in the above step 102. For example, when the relationship between the second angle and the first angle satisfies: the second angle is twice the first angle, that is, θ2=2θ1, and based on the mathematical relationship: And, based on the double angle formula, we can get the formula Wherein, λ is the working wavelength of the angle amplifier determined in step 101, θ1 represents the first angle, and x represents the position of the nanostructure whose phase distribution is to be determined in the x direction. The phase distribution corresponding to the nanostructure can be calculated by this formula:

[0084] Step 104: In the nanostructure database, select data of the nanostructure corresponding to the phase distribution to generate an angle amplifier.

[0085] Among them, when the phase distribution corresponding to each nanostructure is calculated, the data of the nanostructure corresponding to each phase distribution can be found in the nanostructure database, and the angle amplifier (such as an angle amplifier that can achieve one-dimensional amplification, or an angle amplifier that can achieve two-dimensional amplification) can be designed accordingly according to the position where each nanostructure should be (such as the specific position in the x-direction, or the specific coordinates on the xoy plane) to obtain the angle amplifier.

[0086] The design method of the angle amplifier provided in the embodiment of the present invention can directly calculate the phase distribution corresponding to the nanostructures at different positions through a mathematical relationship only according to the working wavelength of the angle amplifier and the relationship between the first angle and the second angle, and directly find the data of the corresponding nanostructure in the nanostructure database to finally generate the angle amplifier. This method can more concisely determine the phase distribution of the nanostructure, and quickly and accurately generate an angle amplifier that can expand the incident light beam to a certain angle.

[0087] The design method of the angle amplifier is introduced below through two specific embodiments.

[0088] Embodiment 1:

[0089] This embodiment provides a transmission-type angle amplifier, the operating wavelength of which is 1550nm, and the relationship between the first angle θ1 of incident light and the second angle θ2 of emission is θ2=2θ1. The half-incident angle of the angle amplifier is 0-15°. According to the formula And θ2<90°, we can get the formula In addition, a relationship diagram between the first angle and the phase distribution of each nanostructure in the angle amplifier can also be obtained (eg Fig.12 as shown); and then according to Fig.12 As shown, the data of the corresponding nanostructure can be found in the nanostructure database to complete the design of the angle amplifier.

[0090] Embodiment 2:

[0091] This embodiment provides a reflective angle amplifier, the operating wavelength of which is 1550nm, and the relationship between the first angle θ1 of incident light and the second angle θ2 of emission is θ2=1.5θ1. The half-incident angle of the angle amplifier is 0-20°, according to the formula And θ2<90°, we can get the formula In addition, a relationship diagram between the first angle and the phase distribution of each nanostructure in the angle amplifier can also be obtained (eg Fig.13as shown); and then according to Fig.13 As shown, the data of the corresponding nanostructure can be found in the nanostructure database to complete the design of the angle amplifier.

[0092] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An angle amplifier, characterized in that: include: A plurality of amplifying units (11), each of the amplifying units (11) corresponding to a phase distribution, the phase distribution representing a corresponding relationship between an incident angle of a light beam incident on the amplifying unit (11) and a phase that can be modulated by the amplifying unit (11); The amplifying unit (11) is capable of modulating a light beam incident at a first angle to emit at a second angle, wherein the first angle is smaller than the second angle, and the second angle is smaller than 90 degrees; Wherein, the angle amplifier is a metasurface; The plurality of amplifying units (11) are arranged in parallel along the x direction; the angle amplifier further comprises a first substrate (12) for growing the plurality of amplifying units (11); the amplifying unit (11) comprises a plurality of identical first nanostructures (111) arranged perpendicular to the x direction, the first nanostructures (111) having the same x coordinate corresponding to the same phase distribution; the first nanostructures (111) are capable of modulating a light beam incident at a first angle to be emitted at a second angle; or, The plurality of amplifying units (11) are arranged in an array; the angle amplifier further comprises a second substrate (14) for growing the plurality of amplifying units (11), and the second substrate (14) is located in an xoy plane, with the plane where the angle amplifier is located serving as the xoy plane; each of the amplifying units (11) comprises at least one second nanostructure.

2. The angle amplifier according to claim 1, characterized in that: The phase distribution of the first nanostructure (111) satisfies in, Indicates the phase distribution corresponding to each first nanostructure (111) in the amplification unit (11) corresponding to the x position of the first substrate (12); represents a constant phase; x represents the position of each first nanostructure (111) in the amplification unit (11) in the x direction; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number, and n o represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

3. The angle amplifier according to claim 1, characterized in that: The phase distribution of the second nanostructure satisfies in, represents the phase distribution of the second nanostructure corresponding to the (x, y) coordinate position of the second substrate (14); the plane where the incident light beam is located is taken as the xoz plane, and the yoz plane is a plane perpendicular to the plane where the incident light beam is located and the plane where the angle amplifier is located; φ2 represents the angle between the projection of the light beam emitted at the second angle on the yoz plane and the z-axis; represents a constant phase; θ2 represents the second angle, θ1 represents the first angle, k represents the wave number and n o represents the refractive index of the spatial medium corresponding to the angle amplifier, and λ represents the wavelength of the light beam.

4. The angle amplifier according to claim 2 or 3, characterized in that: The relationship between the second angle and the first angle satisfies: a multiple relationship, a nonlinear relationship or a trigonometric function relationship.

5. The angle amplifier according to claim 2, characterized in that: The first substrate (12) is transparent in the working wavelength band, and the first nanostructure (111) in the amplifying unit (11) can transmit the light beam incident at the first angle at the second angle.

6. The angle amplifier according to claim 2, characterized in that: It also comprises a reflective layer (13), wherein the reflective layer (13) is arranged between the first substrate (12) and the amplifying unit (11); the reflective layer (13) is capable of reflecting a light beam incident on a surface of the reflective layer (13).

7. The angle amplifier according to claim 1, characterized in that: The angle amplifier is a multi-layer diffractive optical element or a Fresnel lens.

8. A transmitting system, characterized in that: include: The angle amplifier (1), MEMS galvanometer (2) and light source (3) as claimed in any one of claims 1 to 7; The MEMS galvanometer (2) is arranged on the light-emitting side of the light source (3), and is used to inject the light beam emitted by the light source (3) into the angle amplifier (1) at a first angle, and scan along the x-direction; The angle amplifier (1) is arranged on the light-emitting side of the MEMS oscillator (2) and is used to modulate the light beam incident at the first angle to be emitted at the second angle.

9. The transmitting system according to claim 8, characterized in that: The light source (3) comprises a vertical cavity laser.

10. The transmitting system according to claim 8, characterized in that: The light beam emitted by the light source (3) comprises a single collimated laser beam; or, An array of multiple linearly arranged laser beams.

11. The transmitting system according to claim 10, characterized in that: When the light beam emitted by the light source (3) is a single collimated laser beam, the MEMS galvanometer (2) realizes two-dimensional scanning; when the light beam emitted by the light source (3) is a laser array of multiple beams arranged perpendicular to the x-direction, the MEMS galvanometer (2) realizes one-dimensional scanning.

12. The design method of the angle amplifier according to any one of claims 2 to 7, characterized in that: include: Determining the operating wavelength of the angle amplifier; determining a relationship between a first angle of the light beam and a second angle of the light beam after it is emitted from the angle amplifier; Determining the phase distribution of the nanostructure corresponding to each amplification unit in the angle amplifier; In a nanostructure database, data of the nanostructure corresponding to the phase distribution is selected to generate the angle amplifier.

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