A solid-state light beam scanning transmitting and receiving method combining phased array and focal plane

Abstract

The application discloses a solid-state light beam scanning emission and receiving method combining a phased array and a focal plane, and the method comprises the following steps: constructing a two-dimensional optical phased array; modulating the phase of the two-dimensional optical phased array by using an electrical modulation method, so that the light wave emitted by the two-dimensional optical phased array is focused on a first focal plane; installing a focusing lens in the light wave emission direction of the two-dimensional optical phased array, and the focusing lens forms a second focal plane in the direction facing the two-dimensional optical phased array; controlling the positional relationship between the focusing lens and the two-dimensional optical phased array, so that the second focal plane of the focusing lens and the first focal plane are coincident; controlling the angle of the light wave emitted by the two-dimensional phased array by using the electrical modulation method, and the light wave is incident on the focusing lens at the same angle, and is received by a photodetector after reverse focusing.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to a solid-state beam scanning transmission and reception method that combines a phased array and a focal plane array. Background Technology

[0002] Currently, the most widely used beam scanning scheme in the field of LiDAR technology is the traditional mechanical scanning, which mainly relies on mechanical devices such as motors or galvanometers to achieve beam deflection and scanning. The advantage of this scheme is its high level of technological maturity, but due to its shortcomings such as low scanning speed, poor stability, and short device lifespan, it is gradually being replaced by solid-state scanning optical chip solutions.

[0003] The commonly used optical phased array scheme in solid-state lidar relies on multiple antennas simultaneously emitting optical signals with a certain phase relationship. These signals interfere constructively in a specific direction, ultimately emitting a directional beam in that direction. By adjusting the phase relationship between the antennas, beam scanning can be achieved. However, in the implementation of common optical phased array schemes, the scanning angle is limited by the far-field envelope of the antennas. Furthermore, due to limitations in antenna spacing, control complexity, and power consumption, the total optical aperture formed by the optical phased array is limited, making it difficult to achieve narrow beam emission or large-aperture light reception. Traditional focal plane array schemes based on fixed transmitting and receiving pixels can only achieve fixed transmission or receiving angles corresponding to those pixel positions. Summary of the Invention

[0004] One objective of this invention is to provide a solid-state beam scanning transmission and reception method and system that combines a phased array and a focal plane. The method and system improve the design and control method of the two-dimensional optical phased array so that the light signals emitted by each antenna satisfy a specific phase relationship, thereby focusing the light waves emitted by the two-dimensional optical phased array on a specific plane to form the focal plane of the optical phased array. Furthermore, a focusing lens is set so that the focal plane of the focusing lens coincides with the focal plane of the optical phased array, so that the light waves emitted by the two-dimensional optical phased array have good directivity.

[0005] Another objective of this invention is to provide a solid-state beam scanning transmission and reception method and system that combines a phased array and a focal plane. The method and system can move the two-dimensional optical phased array on the focal plane of the two-dimensional optical phased array by adjusting the variable parameters of the phase relationship, thereby achieving beam scanning and avoiding the limitation of the scanning angle range by the far-field envelope of the antenna.

[0006] Another objective of this invention is to provide a solid-state beam scanning transmission and reception method and system that combines a phased array and a focal plane. The method and system employ a lens with a larger aperture than that of an optical phased array at the beam receiving end to achieve more efficient directional reception, and after the two focal planes coincide, it enables continuously adjustable transmission and reception at any angle.

[0007] Another objective of this invention is to provide a solid-state beam scanning transmission and reception method and system that combines a phased array and a focal plane, wherein the method and system can be directly adjusted by program settings to make the first focal plane and the second focal plane automatically coincide.

[0008] To achieve at least one of the above-mentioned objectives, the present invention further provides a solid-state beam scanning emission and reception method combining a phased array and a focal plane, the method comprising:

[0009] A two-dimensional optical phased array is constructed, and the phase of the two-dimensional optical phased array is modulated by an electrical modulation method so that the light wave emitted by the two-dimensional optical phased array is focused on the first focal plane.

[0010] A focusing lens is installed in the light wave emission direction of the two-dimensional optical phased array, and the focusing lens forms a second focal plane facing the direction of the two-dimensional optical phased array.

[0011] The positional relationship between the focusing lens and the two-dimensional optical phased array is controlled so that the second focal plane of the focusing lens coincides with the first focal plane;

[0012] The angle of the light waves emitted by the two-dimensional array is controlled by the electrical modulation method, and the light waves are incident on the focusing lens at the same angle, then focused in reverse and received by the photodetector.

[0013] According to one preferred embodiment of the present invention, the focusing lens is mounted vertically and is parallel to the light wave emission plane of the two-dimensional optical phased array.

[0014] According to another preferred embodiment of the present invention, the two-dimensional optical phased array light wave angle modulation method includes: calculating the coordinate values ​​(x, y, y) of the antenna emitting light waves in the two-dimensional optical phased array. i y j The coordinate value represents the antenna coordinates in the i-th row and j-th column.

[0015] According to another preferred embodiment of the present invention, when the first focal plane and the second focal plane coincide, the distance f between the two-dimensional optical phased array and the focal plane is obtained. z And obtain the corresponding antenna (x) of the emitted light wave. i y jThe coordinates (f) on the focal plane of the two-dimensional optical phased array x f y ), further calculate the corresponding antenna (x) of the current two-dimensional optical phased array. i y j Phase data of the emitted optical signal:

[0016] According to another preferred embodiment of the present invention, after the first focal plane and the second focal plane are installed in an overlapping configuration, the focal length f of the currently configured lens is obtained, and the corresponding antenna (x) is calculated. i y j The distance r between the focal plane and the origin O of the focal plane: Further, the emission angle in a spherical coordinate system with the lens center as the origin is calculated based on the distance r and the lens focal length f.

[0017]

[0018] According to another preferred embodiment of the present invention, the two-dimensional optical phased array is composed of an antenna array, and the coordinate system of the two-dimensional optical phased array is formed outward with the center point of the two-dimensional phased matrix as the origin, wherein the x-axis coordinate and y-axis coordinate of the antenna in the same sequence are the same.

[0019] According to another preferred embodiment of the present invention, when the second focal plane fails to accurately coincide with the first focal plane, the program parameters are automatically adjusted to control the position of the first focal plane so that the first focal plane and the second focal plane automatically coincide.

[0020] To achieve at least one of the above-mentioned objectives, the present invention further provides a solid-state beam scanning and receiving system combining a phased array and a focal plane, the system performing the above-described solid-state beam scanning transmission and reception method combining a phased array and a focal plane.

[0021] The present invention further provides a computer-readable storage medium storing a computer program that can be executed by a processor as described above, a solid-state beam scanning transmission and reception method combining a phased array and a focal plane. Attached Figure Description

[0022] Figure 1 The diagram shown is a flowchart illustrating a solid-state beam scanning transmission and reception method combining a phased array and a focal plane according to the present invention.

[0023] Figure 2 The diagram shown is a structural schematic of a solid-state beam scanning and receiving system combining a phased array and a focal plane according to the present invention.

[0024] Figure 3The diagram shown is a schematic of the optical path structure of the two-dimensional optical phased array and focusing system in this invention.

[0025] Figure 4 The diagram shown is a schematic diagram of the two-dimensional optical phased array antenna array structure in this invention.

[0026] Figure 5 This diagram shows the focal plane optical field distribution at different positions of the focused spot coordinates and the corresponding phase distribution of the antenna in a preferred embodiment of the present invention.

[0027] Figure 6 The diagram shown is a schematic representation of the far-field distribution of an optical signal after passing through a focusing lens, according to a preferred embodiment of the present invention. Detailed Implementation

[0028] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0029] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0030] Please refer to Figures 1-6 This invention discloses a solid-state beam scanning transmission and reception method and system combining phased array and focal plane, wherein specific reference is made to... Figure 2 The system comprises a laser emitter, a circulator, a photodetector, an optical phased array, an electrical modulation system, and a focusing lens. The circulator is mounted in front of the laser emitter, and the photodetector is mounted on the circulator to detect reflected light received by the phased array antenna. A two-dimensional optical phased array is mounted in front of the circulator and connected to the electrical modulation system. The electrical modulation system is used to adjust the focal plane and emission angle of the two-dimensional optical phased array. Notably, the focusing lens is mounted in front of the two-dimensional optical phased array, forming a second focal plane in front of the array. The two-dimensional optical phased array, through the electrical modulation system, forms a first focal plane in front of it using an electrical modulation method, causing the first and second focal planes to coincide. This effectively controls the emission angle of the phased array on the focal plane, thereby controlling the emission angle of the focusing lens.

[0031] Specifically, the electrical modulation system connected to the optical phased array includes a main control module, a DAC (digital-to-analog converter), an operational amplifier, connectors, and a power supply. The main control module includes an MCU (microcontroller unit), an MPU (microprocessor unit), and an FPGA (field-programmable gate array). These devices constitute the electrical modulation chip. The electrical modulation system can use the main control module to perform phase modulation on the phased array and modulate the emission angle of each antenna to the external light wave. The focal length of the two-dimensional optical phased array is modulated to f by the optical modulation system. z ,like Figure 2 In this invention, the distance between the two-dimensional optical phased array plane and the coincident focal plane is defined as a first focal length f1, and the corresponding second focal length between the focusing lens and the coincident focal plane after installation is defined as f2. Through the electrical modulation system, the position of the light wave emitted by the two-dimensional optical phased array antenna on the coincident focal plane is modulated using existing electrical modulation methods. This invention further establishes a coordinate system on the coincident focal plane, defining the coordinates of the focused light spot of the two-dimensional optical phased array on the coincident focal plane as (fx, fy). This invention also establishes a coordinate system on the two-dimensional optical phased array plane, wherein the coordinates of the light-emitting antenna on the two-dimensional optical phased array corresponding to the focused light spot's coordinates on the coincident focal plane as (fx, fy) are defined as (fx, fy). i y j It should be noted that, in this invention, the antenna array configured by the optical image control array can preferably be set to 25*25, that is, x1-x in the X-axis extension direction. 25 There are a total of 25 positions, and along the Y-axis direction y1-y 25 There are a total of 25 location points and 625 antennas. The coordinate system of the two-dimensional optical phased array of this invention takes the center point of the phased array as the origin, and the above-mentioned antenna arrays are configured accordingly. The distance of the points in the X-axis direction from the origin is determined as shown in the following table:

[0032] <![CDATA[x1]]> <![CDATA[x2]]> <![CDATA[x3]]> <![CDATA[x4]]> <![CDATA[x5]]> <![CDATA[x6]]> <![CDATA[x7]]> <![CDATA[x8]]> <![CDATA[x9]]> -196.6 -178.4 -159.4 -148.1 -129.0 -112.6 -101.7 -88.9 -73.4 <![CDATA[x 10 ]]> <![CDATA[x 11 ]]> <![CDATA[x 12 ]]> <![CDATA[x 13 ]]> <![CDATA[x 14 ]]> <![CDATA[x 15 ]]> <![CDATA[x 16 ]]> <![CDATA[x 17 ]]> <![CDATA[x 18 ]]> -53.8 -34.2 -22.6 -2.9 16.7 31.5 49.5 60.9 75.2 <![CDATA[x 19 ]]> <![CDATA[x 20 ]]> <![CDATA[x 21 ]]> <![CDATA[x 22 ]]> <![CDATA[x 23 ]]> <![CDATA[x 24 ]]> <![CDATA[x 25 ]]> 94.3 112.2 -148.1 131.8 158.7 177.2 196.6

[0033] The position point on the Y-axis that is at a distance from the origin is the same as that on the X-axis. The coordinates of the corresponding transmitting antenna on the two-dimensional optical phased array are (x... i y j ), where i and j are the i-th row and j-th column antennas in the X-axis direction and the Y-axis direction, respectively. Further, based on the coordinates (fx, fy) of the focused spot on the coincident focal plane and the coordinates (x, fy) of the corresponding transmitting antenna, i y j The phase of the transmitted optical signal from the antenna in the i-th row and j-th column is calculated using the phase company:

[0034]

[0035] Please refer to Figure 5 The present invention is applicable when the focal length f of the two-dimensional optical phased array is... z When the focal plane is at a focal spot coordinate of 1500um, the focal plane optical field distribution and the corresponding antenna phase distribution at different positions of the focused spot coordinate are obtained by the above formula.

[0036] In this invention, the focal length of the preferred two-dimensional optical phased array is f. z =1500um, and further calculate the distance r between the focused spot and the origin of the phased array coordinate system based on the coordinates (fx, fy) of the focused spot on the coincident focal plane: Furthermore, given a focused light spot (fx, fy), the emission angle of the light wave can be calculated after it passes through the focusing lens. The emission angle The calculation formula is:

[0037] It should be noted that the aforementioned launch angle It is an angle in a spherical coordinate system with the center of the lens as the origin. After the emitted light wave passes through the lens, it can generate an angle like... Figure 6 The far-field distribution is shown.

[0038] Based on the above method and system, this invention focuses light waves emitted by a two-dimensional optical phased array onto a plane. By adjusting the variable parameters of the phase relationship, the focused spot can be moved on the plane. By adding a focusing lens whose focal plane coincides with the focal plane of the optical phased array, the light waves emitted by the optical phased array can propagate in a certain direction, achieving good directivity. Adjusting the variable parameters of the phase relationship enables beam scanning, thus avoiding the limitation of the scanning angle range imposed by the antenna's far-field envelope. For light reception, a lens with a larger aperture than the phased array itself can be used to achieve a greater system receiving capability, thereby improving the ability to detect light intensity and distance. Figure 2 and Figure 3 An optical system consisting of an optical phased array and lenses is demonstrated. The light beam is focused onto the coincident focal plane by the optical phased array. Focal point A and focal point B are two focal points on the coincident focal plane. By controlling and adjusting the optical phased array, the focal points can appear at different positions on the two-dimensional coincident focal plane, thereby realizing the control of the scanning direction of the light beam.

[0039] It is worth mentioning that since the lens is relatively fixed after installation, the second focal plane formed by the lens is a fixed plane. Therefore, when the first focal plane and the second focal plane do not coincide, the first focal plane can be adjusted by the above-mentioned electrical modulation system using an electrical modulation method to make the first focal plane and the second focal plane coincide. In this invention, an automatic adjustment method can be set by the program to automatically configure the relevant modulation parameters of the first focal plane after obtaining the relevant parameters of the second focal plane corresponding to the lens so that the second focal plane automatically coincides.

[0040] In particular, according to embodiments disclosed in this invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs the functions defined in the methods of this application. It should be noted that the computer-readable medium described above in this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wire segments, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless segments, wire segments, optical fibers, RF, etc., or any suitable combination thereof.

[0041] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0042] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments. Without departing from the stated principles, the implementation of the present invention may have any variations or modifications.

Claims

1. A solid-state beam scanning transmission and reception method combining phased array and focal plane, characterized in that, The method includes: A two-dimensional optical phased array is constructed, and the phase of the two-dimensional optical phased array is modulated by an electrical modulation method so that the light wave emitted by the two-dimensional optical phased array is focused on the first focal plane. A focusing lens is installed in the light wave emission direction of the two-dimensional optical phased array, and the focusing lens forms a second focal plane facing the direction of the two-dimensional optical phased array. The positional relationship between the focusing lens and the two-dimensional optical phased array is controlled so that the second focal plane of the focusing lens coincides with the first focal plane; The angle of the light wave emitted by the two-dimensional array is controlled by the electrical modulation method, and the light wave enters the focusing lens at the same angle. After being focused in reverse, it is received by the photodetector. Specifically, the distance between the two-dimensional optical phased array and the focal plane when the first focal plane and the second focal plane coincide is obtained. f z And obtain the corresponding antenna (x) of the emitted light wave. i y j The coordinates of ) on the focal plane of a two-dimensional optical phased array f x , f y ), further calculate the corresponding antenna (x) of the current two-dimensional optical phased array. i y j Phase data of the emitted optical signal: .

2. The solid-state beam scanning transmission and reception method combining phased array and focal plane as described in claim 1, characterized in that, The focusing lens is mounted vertically and is parallel to the light wave emission plane of the two-dimensional optical phased array.

3. The solid-state beam scanning transmission and reception method combining phased array and focal plane as described in claim 1, characterized in that, The two-dimensional optical phased array light wave angle modulation method includes: calculating the coordinates (x, y, y) of the antenna emitting light waves in the two-dimensional optical phased array. i y j The coordinate value represents the antenna coordinates in the i-th row and j-th column.

4. The solid-state beam scanning transmission and reception method combining phased array and focal plane as described in claim 1, characterized in that, After the first and second focal planes are installed with their configurations aligned, obtain the focal length of the currently configured lens. f And calculate the current corresponding antenna (x) i y j The distance r between the focal plane and the origin O of the focal plane: Further based on the distance r and the lens focal length f Calculate the emission angle (θ, φ) in a spherical coordinate system with the lens center as the origin: 。 5. The solid-state beam scanning transmission and reception method combining phased array and focal plane as described in claim 1, characterized in that, The two-dimensional optical phased array is composed of an antenna array, and with the center point of the two-dimensional phased matrix as the origin, the coordinate system of the two-dimensional optical phased array is formed outward, wherein the x-axis coordinate and y-axis coordinate of the antenna in the same sequence are the same.

6. The solid-state beam scanning transmission and reception method combining phased array and focal plane as described in claim 1, characterized in that, If the second focal plane fails to accurately coincide with the first focal plane, the program parameters are automatically adjusted to control the position of the first focal plane so that the first focal plane and the second focal plane automatically coincide.

7. A solid-state beam scanning transmission and reception system combining a phased array and a focal plane array, characterized in that, The system performs a solid-state beam scanning transmission and reception method combining a phased array and a focal plane, as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that can be executed by a processor as described in any one of claims 1-6: a solid-state beam scanning transmission and reception method combining a phased array and a focal plane.

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