CN109444903B - An optical phased array laser radar device - Google Patents

Abstract

The invention discloses an optical phased array laser radar device, which comprises a laser array light source, a double-layer structure liquid crystal optical switch array, an optical switch scanning control device, a double-structure grating array device, a laser reflection signal processing device and an optical lens. The optical lens includes a scanning irradiation lens and a target reflection receiving lens, which are respectively arranged between the double-structured grating array device and the irradiation target, and between the irradiation target and the laser reflection signal processing device, and are respectively used to correct the outgoing beam and the incident beam. In the present invention, ordinary low-power laser diodes are packaged into a laser array light source, and a specially designed double-layer liquid crystal optical switch array is used as a beam channel control device to perform phase modulation on the laser beam under the control of a gating control device. The unique functions of the designed dual-structure grating device achieve various far-field illumination modes. The laser reflection signal processing device receives and processes the laser signal reflected by the target, and calculates information parameters such as distance, azimuth, and speed.

Description

An optical phased array laser radar device

technical field

The invention relates to the technical field of optical phased array in the field of optical detection, in particular to an optical phased array laser radar device.

Background technique

At present, with the rapid development of artificial intelligence technology, target detection, weapon guidance, unmanned driving, autonomous obstacle avoidance and other application fields urgently need a fast, accurate and all-round target detection technology. Radar is the most commonly used detection method. Compared with the radar of traditional mechanical scanning technology, phased array scanning technology uses a large number of independently controlled small antenna units arranged into an antenna array, and each antenna unit is controlled by an independent phase shift switch. By controlling the phases emitted by each antenna element, beams of different phases can be synthesized. Inspired by phase-controlled electronically scanned array radar, solid-state lidar using optical phased array scanning technology has become a research hotspot due to its wide application prospects. Unlike mechanical scanning lidar, since no rotating parts are required, the structure and size of the radar can be greatly compressed, the service life can be improved, and the cost can be reduced; without being limited by the speed and accuracy of mechanical rotation, the scanning speed of optical phased array depends on the used The electronic characteristics of the material can generally reach the order of MHz; the scanning accuracy of the optical phased array depends on the accuracy of the control electrical signal, which can reach more than one thousandth of the order; the beam pointing of the optical phased array is completely controlled by the electrical Signal control, can achieve arbitrary orientation within the allowable angle range, and can perform high-density scanning in key areas; a phased array can be divided into multiple small modules, and each module can be controlled separately to simultaneously lock and monitor multiple Target. However, solid-state lidar also has its corresponding shortcomings. In addition to the central bright pattern, grating diffraction will also form other bright patterns. This problem will cause the laser to form side lobes outside the direction of maximum power and disperse the energy of the laser; especially for optical phased arrays. It is required that the size of the array unit must not be larger than half a wavelength. Generally, the working wavelength of the current laser radar is about 1 micron, so the size of the array unit must not be larger than 500nm. Moreover, the higher the array density, the more concentrated the energy, which raises the requirements for machining accuracy and requires certain technological breakthroughs. Therefore, there is an urgent need for an optical phased array laser radar implementation technology solution that does not depend on limited manufacturing materials, processes, structures, and low cost, so that it can use various flexible, simple, and reliable optical phased array laser radar implementations. application, this product will have a very broad market prospect.

Contents of the invention

The purpose of the present invention is to provide an optical phased array laser radar device, which can meet the requirements of laser radar for higher power and specific light beams of laser sources, and at the same time realize applications such as search, detection, positioning, and tracking.

The technical scheme adopted in the present invention is:

An optical phased array lidar device, comprising a laser array light source, a double-layer structure liquid crystal optical switch array, a double-structure grating array device, an optical switch scanning control device, a laser reflection signal processing device, and an optical lens, and the optical lens includes The scanning irradiation lens and the target reflective receiving lens are respectively arranged between the double-structured grating array device and the irradiation target, and between the irradiation target and the laser reflection signal processing device, and are respectively used to correct the outgoing beam and the incident beam;

The laser array light source is used as the irradiation light source of the system to provide multi-beams and parallel laser beams distributed in a plane array;

The dual-structure grating array device is a structure in which the light-transmitting elements of the coarse grating array are partially embedded with a fine grating, so that its diffraction nesting and space-synchronous interference characteristics produce various steering angles, and the distance direction irradiation intensity can be adjusted. field exposure mode;

The light beam emitted by the laser array light source is controlled by the optical switch scanning control device, and the phase modulation between the light beams and the light beam itself is carried out through the delay gating of the double-layer structure liquid crystal optical switch array. Structural grating array device to complete the optical phased array scanning irradiation on the target;

The number and spacing of the laser diode array elements of the laser array light source, the light-passing window array elements of the double-layer structure liquid crystal optical switch array, and the array elements of the coarse grating of the double-structure grating array device are all in one-to-one correspondence and consistent, The laser reflection signal processing device receives and processes the laser signal reflected by the target, and calculates information parameters such as distance, orientation, and speed.

The double-structured grating array device includes n×m light-transmitting windows arranged in alternating black and white in n rows×m columns, the black part is opaque and the white part is light-transmitting, and the width of any light-transmitting unit adjacent The widths of the opaque units are all equal, and the sum of the width of any transparent unit and the width of its adjacent opaque unit is the unit pitch when phase modulation is performed on this unit, denoted as D, thus forming n rows×m A rectangular device body arranged in black and white alternately, the light-transmitting window is an independent area grating, and s*s light-transmitting circular holes are evenly distributed in the area array grating, wherein the area grating The unit spacing is recorded as d, then D is an integer multiple of d, where n, m, s, D, and d are all positive integers.

When the dual-structure grating array device is in use, each light-transmitting unit of the array corresponds to a laser diode light source and a phase modulation window, and the wavelength of the laser diode light source is , then d is not greater than 1/2.

The double-layer structure liquid crystal optical switch array includes a first layer of liquid crystal panels and a second layer of liquid crystal panels arranged on the top and bottom, and the first layer of liquid crystal panels is sequentially provided with a first alignment film and a row scanning electrode in parallel. 1. The upper glass plate and the upper polarizer, the second alignment film, the row signal electrodes and the middle glass plate are arranged in parallel on the bottom of the first liquid crystal plate;

The third directional film and the column scanning electrode are arranged in parallel on the pole plate of the second layer of liquid crystal plate successively, and the fourth directional film, the column signal electrode, the lower glass plate and the lower polarizer are arranged in parallel on the bottom of the second layer of liquid crystal plate; The scanning electrodes and the row signal electrodes are perpendicular to each other and aligned up and down, the column signal electrodes and the row signal electrodes are perpendicular to each other and aligned up and down, and the column scanning electrodes and the column signal electrodes are perpendicular to each other and aligned up and down;

The first oriented film, the second oriented film, the third oriented film and the fourth oriented film are all made of a thin layer of polymer organic matter, which is oriented and rubbed so that the rod-shaped liquid crystal molecules are parallel to the glass surface and processed along the orientation. The direction arrangement is used to make the molecular orientation of the upper surface of the crystal of each layer of liquid crystal panel and the molecular orientation of the lower surface of the crystal perpendicular to each other;

There are n row-scan electrodes, and the n row-scan electrodes are evenly divided into n1 groups, and there are n2 row-scan electrodes in each group, then n=n1*n2; Group widths and intervals are equally sized;

There are m column scanning electrodes, and the m column scanning electrodes are evenly divided into m1 groups, and there are m2 column scanning electrodes in each group, then m=m1*m2; the width and interval of the electrodes in the group are distributed in equal dimensions, The width and interval of each group are distributed in equal dimensions;

The n groups of row scanning electrodes correspond to n3 row signal electrodes, and the m groups of column scanning electrodes correspond to m3 column signal electrodes.

The optical switch scanning control device includes a holding circuit, a gating circuit, an optical switch gating controller and an independent controllable voltage stabilized power supply; the control output end of the optical switch gating controller is connected to the input end of the gating circuit , the output end of the gating circuit is connected to the electrode in the switch array to be controlled through the holding circuit; the described independent controllable voltage stabilized power supply is used to supply power to the holding circuit, the gating circuit and the optical switch gating controller; the described The holding circuit is composed of a plurality of holding units with the same structure, and the holding circuit includes a row/column signal holding circuit, a column scanning holding circuit and a row scanning holding circuit; It constitutes a row/column signal gating circuit, a column scanning gating circuit and a row scanning holding circuit.

The holding circuit includes a peripheral circuit composed of an operational amplifier MAX419 and a capacitor; the gating circuit uses a high-speed CMOS multiplexing circuit CA74HC4051, or uses a CA74HC4067 to save the number of chips used.

The laser array light source is composed of an array of n rows×m columns of optical array elements arranged on an expandable frame. The optical array elements are individually packaged individuals, and the optical array elements include pressure rings, collimating lenses, Adjusting spacers, laser diodes, pre-drive circuits, sockets, metal casings and organic silica gel, the sockets are fixed at one end of the metal casing and connected to the pre-drive circuits; the laser diode packaged by the heat sink is fixed in the middle of the metal casing Position, the pins of the laser diode are connected to the output end of the pre-drive circuit and are potted with organic silica gel; the collimator lens is fixed on the other end of the metal shell through the adjustment gasket and the pressure ring;

The expandable frame includes upper and lower fixed partitions arranged in parallel, n rows×m columns of array elements are arranged in a vertical array between the upper and lower fixed partitions, and the array elements are parallel to each other, and The socket end is at the lower end, and the interval between the array elements is uniform, and the interval is filled with a potting material, the potting material is a mixture of aluminum powder and silica gel, and the array light source is also packaged as a whole while filling;

The drive circuit includes a filter circuit and a drive and brightness control circuit, the input end of the filter circuit is connected to the output end of the socket, the output end of the filter circuit is connected to the input end of the drive and brightness control circuit, and the output of the drive and brightness control circuit The terminal is connected to the corresponding pin of the laser diode.

The n×m laser array light source corresponds to an optical switch array with n×m light-passing windows, and a double-structure grating array device with n×m coarse grating array elements, and a corresponding light source array element communicates with an optical switch The optical window and the coarse grating elements of a double-structured grating array form a micro-optical phased array illumination channel, and n×m micro-optical phased-array illumination channels work together in a certain order and with a phase difference to form an overall optical phased-array based The laser radar scanning irradiation working mode of the array technology, the reflection signal of the target to the irradiation laser is received by the avalanche photodiode device and the relevant information parameters are solved by the microcontroller.

The liquid crystal optical switch array with a double-layer structure adopts the sequential strobe and hold working mode of "gate → hold → strobe → hold → strobe →...", specifically for the requirements of different scanning working modes on the driving signal Different, among them, for the three gating (scanning) working modes of linear scanning, sectoral scanning and deep focusing, the corresponding driving signal characteristics and timing requirements are as follows:

①Linear scanning: the delay time is constant or changes regularly, the driving signal amplitude is constant, all elements are selected one by one, and only one element can be selected at any time;

②Sector scan: The delay time changes according to the sector scan rule, the driving signal amplitude is constant, all elements are selected one by one, and the elements selected in the previous period remain selected;

③Irradiation intensity control: The delay time changes regularly, the driving signal amplitude changes according to the rules, all elements are gated one by one, and the elements gated in the previous period remain gated.

The optical phased array laser radar device of the present invention encapsulates ordinary low-power laser diodes into a laser array light source, provides a new type of multi-beam laser irradiation source for the laser radar, and adopts a specially designed double-layer structure liquid crystal As a beam channel control device, the optical switch array performs phase modulation on the laser beam under the control of the gating (scanning) control device, and uses the unique functions of the specially designed double-structure grating device to achieve various far-field irradiation modes. It adopts high sensitivity, The low-noise InGaAs photodetector receives the target laser reflection signal and calculates the measurement parameters to realize applications such as search, detection, positioning, and tracking. At the same time, laser array light sources, double-layer liquid crystal optical switch arrays, and double-structure grating devices It can also be independently applied to other optical measurement and control systems.

Description of drawings

Fig. 1 is a schematic structural diagram of the present invention;

Fig. 2 is a schematic diagram of the coarse grating structure of the dual-structure grating array device of the present invention;

Fig. 3 is a schematic diagram of the fine grating structure of the dual-structure grating array device of the present invention;

4 is a schematic diagram of the working principle of the optical phased array of the present invention;

Fig. 5 is a structural diagram of a double-layer liquid crystal optical switch array of the present invention;

Fig. 6 is a structural diagram of a laser array light source of the present invention;

Fig. 7 is a schematic structural view of the array source in the laser array light source of the present invention;

8 is a schematic circuit diagram of a light source drive circuit in the laser array light source of the present invention;

Fig. 9 is a functional block diagram of the optical switch gating (scanning) control device of the present invention;

Fig. 10 is 8 channel gates (scanning) of the present invention, keep the control circuit diagram;

Fig. 11 is a circuit diagram of the optical switch scanning control of the present invention.

Detailed ways

As shown in Figure 1, the present invention includes a laser array light source 1, a double-layer structure liquid crystal optical switch array 2, a double-structure grating array device 3, an optical switch scanning control device 4, a laser reflection signal processing device 5, and an optical lens 6. The optical lens includes a scanning irradiation lens and a target reflective receiving lens, which are respectively arranged between the double-structured grating array device 3 and the irradiation target and between the irradiation target and the laser reflection signal processing device 5, and are respectively used to process the outgoing beam and the incident beam correction;

The laser array light source 1 provides multi-beams and parallel laser beams distributed in a planar array as the irradiation light source of the system;

The dual-structure grating array device 3 is a structure in which the light-transmitting elements of the coarse grating array are partially embedded with a fine grating, so that its diffraction nesting and space-synchronous interference characteristics produce various steering angles and the irradiation intensity in the distance direction is adjustable. Far-field illumination mode;

The light beam emitted by the laser array light source 1 is controlled by the optical switch scanning control device 4, and the phase modulation between the light beams and the light beam itself is carried out through the delay gating of the double-layer structure liquid crystal optical switch array 2 , combined with the dual-structure grating array device 3 to complete the optical phased array scanning irradiation on the target;

The number and spacing of the laser diode array elements of the laser array light source 1, the light-passing window array elements of the double-layer structure liquid crystal optical switch array 2, and the coarse grating array elements of the double-structure grating array device 3 are all in one-to-one correspondence and Keeping consistent, the laser reflection signal processing device receives and processes the laser signal reflected back from the target, and calculates information parameters such as distance, orientation, and speed.

As shown in FIG. 2 and FIG. 3, the double-structured grating array device 3 includes n×m light-transmitting windows, which are arranged and distributed according to n rows×m columns of rectangular black and white alternately, the black part is opaque and the white part is light-transmitting, The width of any light-transmitting unit (window) 8 is equal to the width of its adjacent opaque unit 9, and the sum of the width of any light-transmitting unit 8 and the width of its adjacent opaque unit 9 is phased for this unit The cell spacing during modulation is denoted as D, thus forming a device body with n rows×m columns of rectangular black and white alternately arranged. The light transmission window is an independent area grating, and the area array grating is evenly distributed There are s*s light-transmitting round holes, where the unit spacing of the area grating is recorded as d, then D is an integer multiple of d, where n, m, s, D, and d are all positive integers.

Apply photolithography and etching technology, adopt matrix area array structure, arrange and distribute in accordance with n rows × m columns of rectangular black and white, the black part is opaque, the white part is light-transmitting, and the white light-transmitting part itself is also an independent area array grating , the grating parameters are specially designed according to the laser wavelength corresponding to the device application, so that it has a high diffraction efficiency.

When the double-structure grating device is in use, each light-transmitting unit of the array corresponds to a laser diode light source and a phase modulation window, and the wavelength of the laser diode light source is λ, then d is not greater than 1/2λ,

As shown in FIG. 2 and FIG. 3 , the dual-structure grating array device 3 , the so-called double structure means that a thick grating is embedded with a fine grating. The double-structure grating array device is composed of coarse and fine grating double structures. Each light-transmitting unit of the coarse grating corresponds to a beam of laser irradiation array (a beam of laser light emitted by a laser diode). The phase modulation of a single beam of a phased array laser radar is changed to the modulation of multiple beams of a laser array, which breaks through the limitation that the size of the phase modulation device array unit must not be greater than 500nm (corresponding to a laser wavelength of about 1 micron), making it possible to use conventional The materials, processing technology and process used to make the device used in the phase modulation of the optical phased array; each of the above-mentioned light-transmitting units is a fine grating array, similar to the traditional device, its grating parameters depend on the laser wavelength, for a single The effect of the combination of coarse and fine gratings is that the materials for making devices are easy to obtain, the requirements for microstructure processing are greatly reduced, the requirements for manufacturing processes and equipment are simplified, and the applicability of devices is greatly improved.

As shown in Figure 1, the dual-structure grating device and the optical phase modulation device are combined to form a two-dimensional array optical phased array component, and after the laser array light source 1 is incident on the optical phased array component, each unit of the phase modulation device 2 is controlled The phase difference between the adjacent beams and the beam phase difference between the units makes the phase of the output light wave of the beam through the double-structure grating array device 3 in the same direction in the specified direction, thereby realizing constructive interference in this direction, and the phase of the output light is at the same time. Destructive interference occurs in other directions, so that the light is focused to the corresponding position at the target scanning position 7 after passing through the lens. The combination of the larger structural size of the coarse grating and the microstructural size of the fine grating can obtain a large-scale device while satisfying the requirements of The use function of the beam scanning device in the optical phased array laser radar system, and the cost is low, the process is simple, and the reliability is high when used. A laser area array component is formed by n×m light-transmitting units, and the direction scanning and irradiation intensity control of the output light of the area array component can be realized by controlling the phase and intensity of the output light of each laser diode. It is applied to such as laser radar, laser measurement distance and other occasions; as shown in Figure 4, in specific use, each light transmission hole of the coarse grating corresponds to the beam of an independent laser diode device, and the beam phase difference of the laser diode device between adjacent light transmission holes is ΔΦ, and the outgoing light deflection angle.

θ _s = arcsin[(ΔΦ·λ)/(2π·D)]

Among them, λ is the wavelength of the incident light, D is the distance between adjacent modulation units (or coarse grating parameters), and ΔΦ is the phase difference between adjacent units. Directional scanning can be realized by controlling the magnitude and positive or negative of the phase difference ΔΦ. For a two-dimensional area array device, controlling the phase difference between row units can realize azimuth scanning, and controlling the phase difference between column units can realize pitch scanning and control focus The lens can realize the front and rear focus depth changes, and control the opening degree of the optical switch to control the illumination intensity.

出射光偏转角度保持与粗光栅调制偏转角度一致，即Each light beam inside the fine grating can be modulated similarly to the above, or not modulated, and the overall effect after modulation is better than without modulation. During modulation, the phase difference between adjacent beams is controlled by the phase modulation device as

The deflection angle of the outgoing light remains consistent with the deflection angle of the coarse grating modulation, that is,

为相邻单元相位差，同时需要保证ΔΦ是

的整数倍。Among them, λ is the wavelength of the incident light, d is the distance between adjacent modulated beams (or fine grating parameters),

is the phase difference between adjacent units, and it is necessary to ensure that ΔΦ is

Integer multiples of .

The present invention uses a special structural design combining coarse and fine gratings to solve the problem of laser array integration and the miniaturization of the pitch of phase modulation units. The parameters of the coarse grating meet the difficulties of multi-laser integration and device installation; The phase modulation device realizes the miniaturization of phase modulation unit spacing, eliminates side lobes, and improves efficiency and precision.

As shown in Figure 5, the described double-layer structure liquid crystal light switch array 2 is made up of the first layer liquid crystal panel 28 and the second layer liquid crystal panel 29 that are arranged up and down, and the upper layer liquid crystal panel 28 is arranged in parallel successively The first alignment film 17, the row scanning electrode 22, the upper glass plate 21 and the upper polarizer 27, the second alignment film 16, the row signal electrode 24 and the middle glass plate 30 are arranged in parallel in sequence below the first layer of liquid crystal panel 28; The third directional film 18 and the column scanning electrode 23 are arranged in parallel successively on the pole plate of the second layer liquid crystal panel 29, and the fourth directional film 19, the column signal electrode 25, and the lower glass plate are arranged in parallel successively below the second layer liquid crystal panel 29. 20 and the lower polarizing plate 31; the row signal electrodes 24 and the column signal electrodes 25 are respectively connected with electrode lead wires 26, and the electrode lead wires 26 are used to make the layout of the lead pins reasonable and convenient for the row signal electrodes 24 and column The signal electrodes 25 are respectively connected to the row scanning electrodes 22 and the column scanning electrodes 23 on the same horizontal plane, which is convenient to be connected with the drive control circuit to control the power supply of the row signal electrodes 24 and the column signal electrodes 25; there are n number of the row scanning electrodes 22, The n row scanning electrodes are evenly divided into n1 groups, and there are n2 row scanning electrodes in each group, then n=n1*n2; the electrode width and spacing in the group are distributed in equal dimensions, and the width and spacing in each group are distributed in equal dimensions;

The intermediate glass plate 30 in the present invention is a double-sided electrode plate, that is, the glass plate shared by the first layer of liquid crystal plate 28 and the second layer of liquid crystal plate 29. In actual use, two glass plates can also be used to process corresponding electrodes respectively. However, it is obviously not as cost-effective as sharing a glass plate. By sharing a glass plate, the corresponding electrodes can be set on the upper and lower end faces of the glass plate at the same time, and processed in one piece.

There are m column scanning electrodes 23, and the m column scanning electrodes are evenly divided into m1 groups, and there are m2 column scanning electrodes in each group, then m=m1*m2; the electrode width and spacing in the group are distributed in equal dimensions , the width and interval of each group are distributed in equal dimensions;

The n1 group of row scanning electrodes corresponds to n3 row signal electrodes, and the m1 group of column scanning electrodes corresponds to m3 column signal electrodes, wherein n, n1, n2, m, m1, m2, n3 and m3 are all positive integers.

The row scanning electrodes 22 and the row signal electrodes 24 are perpendicular to each other and aligned up and down, the column signal electrodes 25 and the row signal electrodes 24 are perpendicular to each other and aligned up and down, and the column scanning electrodes 23 and the column signal electrodes 25 are perpendicular to each other and aligned up and down; It is a vertical relationship, so it must correspond to each other, that is, there cannot be a part of the row scanning electrode 22 below which there is no corresponding row signal electrode 24, otherwise there cannot be a row scanning electrode 22 above the part of the row signal electrode 24 The same relationship exists between the column scanning electrodes 23 and the column signal electrodes 25, thus forming the diversity feature of the double-layer structure optical switch control method.

The first oriented film 17, the second oriented film 16, the third oriented film 18 and the fourth oriented film 19 are all made of a thin layer of macromolecular organic matter, which is processed by directional rubbing to make the rod-shaped liquid crystal molecules parallel to the glass surface. , arranged along the direction of orientation treatment, used to make the molecular orientation of the crystal upper surface of each layer of liquid crystal panel and the molecular orientation of the crystal lower surface perpendicular to each other. The orientation of the liquid crystal molecules is gradually twisted, twisting 90° from the upper surface to the lower surface of the liquid crystal, so it is called a twisted nematic liquid crystal panel. The polarization direction of the upper polarizer 27 is identical with the upper surface molecular orientation of the first layer liquid crystal panel 28 crystals, and the upper surface molecular orientation of the second layer liquid crystal panel 29 crystals is parallel to the upper surface molecular orientation of the first layer liquid crystal panel 28 crystals, and the lower surface The polarization direction of the polarizer 31 is consistent with that of the upper polarizer 27 .

When all electrodes are at low level, after the light beam is incident on the upper polarizer 27, the linearly polarized light that is the same as the molecular orientation on the surface of the first layer of liquid crystal plate 28 is formed through the upper polarizer 27, and enters the first layer of liquid crystal plate 28, and the polarization direction follows the direction of the liquid crystal. The long axis of the molecule rotates 90°, and emits linearly polarized light perpendicular to the molecular orientation on the upper surface of the second-layer liquid crystal panel 29, so the light cannot pass through the 29 layers of the second-layer liquid crystal panel, that is, the array element is in an "off" state; row scanning and When the column scanning electrodes are all energized and the potential is higher than a specific threshold, and the corresponding signal electrode is grounded, the light beam enters the upper polarizer, passes through the polarizer to form linearly polarized light with the same orientation as the surface molecules of the first layer of liquid crystal panel 28, and enters the first layer Liquid crystal panel 28, because the polarization direction of electric field effect light no longer rotates when propagating in the first layer liquid crystal panel 28 and remains unchanged, with the linearly polarized light that is parallel to the molecular orientation on the second layer liquid crystal panel 29, the same principle After the light passes through the 29th layer of the second liquid crystal panel, the polarization direction of the outgoing light is parallel to the original polarization direction, and the light exit can be realized through the lower polarizer, that is, the array element is in the "on" state.

The optical switch scanning control device includes a holding circuit, a gating circuit, an optical switch gating controller and an independent controllable voltage stabilized power supply; the control output end of the optical switch gating controller is connected to the input end of the gating circuit , the output end of the gating circuit is connected to the electrode in the switch array to be controlled through the holding circuit; the independent controllable voltage stabilized power supply is used to supply power to the holding circuit, the gating circuit and the optical switch gating controller; the The holding circuit described above is composed of a plurality of holding units with the same structure, and the holding circuit includes a row/column signal holding circuit, a column scanning holding circuit and a row scanning holding circuit; The unit constitutes a row/column signal gating circuit, a column scanning gating circuit and a row scanning holding circuit.

As shown in Fig. 6 and Fig. 7, the laser array light source 1 of the present invention is composed of n rows×m columns of array elements 46 arrayed on an expandable frame 45, and the array elements 46 are individually packaged individual, and the array element 46 includes a pressure ring 54, a collimating lens 53, an adjustment spacer 52, a laser diode 51, a pre-drive circuit 49, a socket 47, a metal casing 48 and an organic silica gel 50, and the socket 47 is fixed on One end of the metal shell 48 is connected to the pre-drive circuit 49; wherein, the light source is a laser diode 51, an adjustment spacer 52 and a collimation lens 53 to form a collimation correction link, and a certain range of adjustment is performed by adjusting the thickness of the spacer 52 ; The specially designed pre-drive circuit 49 has the function of identifying the polarity of the power supply, which can be adaptively connected to an external power supply, and can be used for both AC and DC.

The array element 46 independently packages the laser diode 51, pre-driver circuit 49, and collimator lens 53 into a single body, and the array is not limited by the array form and the number of array elements, so that the corresponding control methods such as working mode, scanning, and correction are relatively It is independent and easy to realize the implementation of different technical routes, so that the overall performance of the array is minimized by the characteristics of individual array elements.

Described laser diode 51 is the laser diode of heat sink package, and the laser diode of heat sink package is fixed in the middle position in metal case 48, and the pin of the laser diode of heat sink package is connected with the output end of pre-drive circuit 49 and passes through Potting with organic silica gel 50; the collimating lens is fixed on the other end of the metal shell through the adjustment gasket and the pressure ring;

The expandable frame includes an upper fixed partition 41 and a lower fixed partition 42 arranged in parallel, n rows×m columns of array elements 46 are arranged in a vertical array between the upper and lower fixed partitions, and the array elements 46 are parallel to each other, and the socket end is at the lower end, the interval between the array elements is uniform, and the interval is filled with potting material 43. The potting material 43 is a mixture of aluminum powder and silica gel. Encapsulate the light source of the array 46 as a whole; as shown in Figure 6, the connection between the array element 46 and the external circuit adopts a connector 47, and the connector 47 includes two electrodes for the power supply and one electrode for the control signal, and the specially designed power supply polarity is automatically identified The circuit can be adaptively connected to an external power supply, and there is no need to worry about the right or wrong connection polarity (regardless of positive and negative poles). external circuit connections. When the three-wire system is connected, the input power is a DC constant voltage source, which is used as the driving power of the semiconductor laser diode; the brightness of the semiconductor laser diode is independently controlled by the brightness adjustment signal, and the field effect switch is controlled by changing the duty cycle or frequency of the brightness adjustment signal. On/off to adjust laser brightness.

When the two-wire system is connected, the brightness adjustment signal is invalid (grounded), and the input power supply is a variable-amplitude DC voltage source, and the on-off of the voltage controls the on-off of the semiconductor laser diode;

Figure 6 is a schematic diagram of the composition of a laser array light source. The laser array light source used for optical scanning is made into a distributed laser source that can be applied to an optical phased array laser radar by using the current common semiconductor laser diode device. The array element is packaged and controlled independently; the array element is fixed by the upper and lower metal partitions and then encapsulated in the expandable metal frame, filled with silicone sealant; the metal frame of the array packaging is provided with a half-shaped guide groove, and multiple arrays can pass through the I-shaped lock. , Quickly form array components of different shapes and sizes, suitable for different application requirements.

A prominent feature of the laser array light source is that the array element independently packages the illuminant, pre-driver and collimation correction into a single unit, which is not limited by the array form and the number of array elements, so that the corresponding working mode, scanning , Correction and other control methods are relatively independent and easy to implement different technical routes, and are not affected by the characteristics of the array elements. The convenient and expandable packaging frame is also one of the characteristics of the laser array light source. On the basis of the independent packaging of the array elements, the expansion connection of the packaging frame is an important indicator of product applicability. The I-shaped through-type guide groove, when splicing and expansion is required, the two array modules that are opposite to each other are connected and fixed by the I-shaped lock. It is not limited by the splicing and expansion form, and does not increase auxiliary components and difficulty. The realization of array expansion is equivalent to simple parallel application of devices.

As shown in Figure 8, the drive circuit includes a filter circuit and a drive and brightness control circuit, the input end of the filter circuit is connected to the output end of the socket, the output end of the filter circuit is connected to the input end of the drive and brightness control circuit, and the drive The corresponding pin of the laser diode is connected with the output end of the brightness control circuit. The drive circuit also includes a power supply polarity conversion circuit, which is a rectification module for converting direct current or alternating current of different polarities into direct current with a certain polarity, which is used as a power supply for subsequent circuits. The filter circuit includes a pre-filter and a post-filter, which are respectively arranged at the input end and the output end of the rectification module, and both the pre-filter and the post-filter adopt capacitor filtering. The drive and brightness control circuit includes a reference voltage, a comparator, a bias resistor R1, a calibration resistor R2, a current-limiting resistor R3 and a field effect tube, which are used to control the laser diode load on and off and brightness according to an external control signal. Regulatory control.

The pre-drive circuit is composed of socket, pre-filter, polarity conversion, post-filter, reference voltage, comparator, bias, feedback, calibration, field effect high-speed switch tube and load (laser diode), and the rectifier circuit input terminal and pre-filter Connect the socket power input pin after parallel connection, the output terminal of the polarity conversion circuit is connected in parallel with the post-filtering circuit to supply power to the subsequent circuit; the input terminal of the reference voltage chip is connected to the brightness adjustment pin of the socket, and the output terminal is connected to the reference voltage input terminal of the comparator, and the comparator The output of the field effect high-speed switching tube controls the on/off of the switch to realize the on/off of the semiconductor laser diode and the adjustment of the brightness, and also includes bias, feedback, calibration and current limiting circuits. The front end is connected to the external circuit through the socket, and the output of the back end directly drives the semiconductor laser diode. The power input through the socket is filtered by C1 and then input to the input terminal of the rectification module (equivalent to the aforementioned polarity conversion), and the output terminal of the rectification module is filtered by C2 to supply power for the comparator and the semiconductor laser diode. The external brightness adjustment signal is connected to the input terminal of the reference voltage module through the socket, and the output terminal of the reference voltage module is connected to the voltage reference terminal of the comparator as a reference for brightness control. The output terminal of the comparator is connected to the gate of the field effect switch tube to control The on/off of the field effect switch tube realizes the on/off control and brightness adjustment of the semiconductor laser diode. The above-mentioned rectification link has the function of self-adjustment (also called self-adaptive) of power supply polarity, so that the external power supply does not need to distinguish positive and negative poles, and can be directly connected (regardless of whether the polarity of the power supply applied to the input terminal of the rectification module is upper positive or lower negative, It is still upper negative and lower positive, and the voltage polarity loaded on C2 at the output end of the rectifier module is still upper positive and lower negative, and the subsequent circuit still works normally), and it is also suitable for AC power supply.

The n×m laser array light source corresponds to an optical switch array with n×m light-through windows, and a double-structure grating array device with n×m coarse grating array elements, one light source element and one optical switch light-through window and The coarse grating elements of a double-structure grating array form a micro-optical phased array illumination channel, and n×m micro-optical phased-array illumination channels work together in a certain order and with a phase difference to form an overall optical phased-array technology-based In the scanning irradiation mode of the laser radar, the reflected signal of the target to the irradiation laser is received by the avalanche photodiode device and the relevant information parameters are solved by the microcontroller.

Between adjacent micro-optical phased array irradiation channels, the phase difference between the last modulated beam of the front channel and the first modulated beam of the rear channel needs to be strictly controlled. According to the scanning working mode, it is controlled by the switch scanning control device. According to the adjacent channel The interval size of the device and the width of the optical switch scanning electrode in the dimension direction calculate the phase difference between the last modulated beam of the front channel and the first modulated beam of the rear channel, and the controller generates a delay control signal for adjustment to realize all Requirements for phase difference consistency between illumination channels of micro-optical phased arrays.

The double-structure grating array device is composed of coarse and fine grating double structures. Each light-transmitting unit of the coarse grating corresponds to a beam of laser irradiation array (a beam of laser light emitted by a laser diode). The phase modulation of a single beam of phased array lidar is changed to the modulation of multiple beams of a laser array, which breaks through the limitation that the size of the array unit must not be greater than 500nm (corresponding to a laser wavelength of about 1 micron), making it possible to use conventional materials , processing technology and process to produce a device for phase modulation in an optical phased array; each of the above-mentioned light-transmitting units is a fine grating array, similar to traditional devices, and its grating parameters depend on the laser wavelength. For a single beam of laser The effect of the combination of coarse and fine gratings is that the materials for making devices are easy to obtain, the requirements for microstructure processing are greatly reduced, the requirements for manufacturing processes and equipment are simplified, and the applicability of devices is greatly improved.

The liquid crystal light switch array with a double-layer structure is essentially different from the liquid crystal light switch array with a common single-layer structure in application mode and effect, and is different from the traditional liquid crystal light switch when gating row by row (or column). "Gating→Off→Gating→..." pulse working mode, but adopts "strobing→holding→strobing→maintaining→strobing→..." sequential strobing and keeping working mode, so it has a similar function to the opening and closing of curtains The gradual opening effect of the process.

The current common semiconductor laser diode device is used to make a distributed laser source that can be applied to optical phased array lidar, and the array elements are independently packaged and controlled; the array elements are fixed by upper and lower metal partitions and then packaged in an expandable metal frame. Filling and sealing; the metal expandable frame of the array packaging is provided with a semi-I-shaped guide groove, and multiple arrays can be quickly formed into array components of different shapes and sizes through the I-shaped locking method, which is suitable for different application requirements.

As shown in Figure 9, the optical switch gating (scanning) control device consists of a row/column signal control circuit, a row/column scanning control circuit, an independently controllable high-precision regulated power supply, an optical switch gating controller, and a built-in control code The row/column signal control circuit is composed of the row/column signal gate circuit and the row/column signal hold circuit. The row/column scan control circuit is composed of the row/column scan gate circuit and the row/column scan hold circuit. The column signal control circuit, the row/column scanning control circuit and the optical switch gating controller are respectively provided with different working voltages by independent controllable high-precision regulated power supplies, and the row/column signal control circuit is controlled by the optical switch gating controller under the unified coordination It cooperates with the row/column scanning control circuit to control the linear scanning and sector scanning; the independent controllable high-precision regulated power supply is responsible for the control of the irradiation intensity.

As shown in Figure 10, the row/column signal gating circuit and the row/column scanning gating circuit are composed of high-speed CMOS multi-channel analog multiplexer/demultiplexer integrated circuit chips, and the row/column signal holding circuit And the row/column scanning and holding circuit is composed of integrated operational amplifiers. The strobing circuit cooperates with the holding circuit. Under the control of the controller, the "strobe"→"hold"→"strobe"→...cycle of the channel is realized.

Different gating (scanning) working modes have different requirements for driving signals. For the three gating (scanning) working modes of linear scanning, sectoral scanning and deep focusing, the corresponding driving signal characteristics and timing requirements are as follows:

①Linear scanning: The delay time is constant or changes regularly, the driving signal amplitude is constant, all elements are selected one by one, and only one element can be selected at any time.

②Sector scan: The delay time changes according to the sector scan rule, the amplitude of the driving signal is constant, all elements are selected one by one, and the elements selected in the previous period remain selected.

③Irradiation intensity control: The delay time changes regularly, the driving signal amplitude changes according to the rules, all elements are gated one by one, and the elements gated in the previous period remain gated.

The double-layer structure liquid crystal optical switch array shown in Fig. 5, when described double-layer structure liquid crystal optical switch array, when normally off state, all electrodes of upper and lower layers are in low level, and all array elements (optical windows) are in light-blocking state, In the row scanning (or column scanning) working mode, set the row signal (or column signal) electrodes A, B, C, D, E...etc. All units on one layer (including all 8×8 optical windows of this layer, and all 10×10 optical channels in the window) are in the conduction state, and then line-scanned sequentially according to a certain time interval (corresponding to the phase) (or column scanning) electrodes a, b, c, d, e, f, ... etc. are at high level, so that the light transmission of the upper and lower liquid crystals of the corresponding unit is no longer twisted in the axial direction under the action of the electric field and transmits light. Realize the gradual opening similar to the curtain opening and closing process. There is a certain phase difference (delay) between the beams controlled (modulated) by the liquid crystal optical switch array. This process is the phase modulation process of the beams, also known as the optical phase control process. The liquid crystal light switch array with a double-layer structure is essentially different from the liquid crystal light switch array with a common single-layer structure in application mode and effect, and is different from the traditional liquid crystal light switch when gating row by row (or column). "Gating→Off→Gating→..." pulse working mode, but adopts "strobing→holding→strobing→maintaining→strobing→..." sequential strobing and keeping working mode, so it has a similar function to the opening and closing of curtains The gradual opening effect of the process.

The preferred embodiments of the present invention will be described in detail below; it should be understood that the preferred embodiments are only for illustrating the present invention, rather than limiting the protection scope of the present invention.

The system light source adopts 8×8 laser array light source. For the input control link, choose a small-pitch 3-wire socket (ZH1.0-3P); for the voltage polarity conversion link, choose a fast rectification integrated chip (MP6908GJ PD), and take C1=C2=0.22μF; for the drive and brightness control link, the reference voltage The circuit selects LM1403, the comparator selects LM358, the high-speed switch circuit selects 2SJ461 FET P-channel-50V-100mA, R1=1k, R2=R3=51Ω; for the load driving link, select a laser diode with a wavelength of 980nm (GH series), The outer diameter is 3.3mm, the length is 8.27mm, the driving voltage is ≦3.0V, and the output power is 120mW. Collimating lens The lens adopts a molded glass aspheric lens with a diameter of 3.0mm and a focal length of 2.0mm.

Phase modulation adopts 8×8 double-layer liquid crystal light switch array. The size of the array element is 2mm×2mm, the interval between the array elements is 2mm, and the shape and size are 18.5mm×18.5mm×0.5mm in length×width×thickness. The basic parameters are as follows:

① The shape and size of the line scanning electrodes: rectangular strip electrodes, 8 groups in total (n1=8), with an interval of 2 mm between groups. There are 10 electrodes in each group (n2=10), and the interval between electrodes is 100 μm. There are 80 electrodes in total (n=80), and the size of each electrode is 14 mm×100 μm×150 nm in length×width×thickness.

②Shape and size of row signal electrodes: 8 rectangular strip electrodes (n3=8), the interval between strips is 2mm, and the size of each electrode is 14mm×2mm×150nm in length×width×thickness.

③Shape and size of column scanning electrodes: rectangular strip electrodes, 8 groups in total (m1=8), with an interval of 2mm between groups. There are 10 electrodes in each group (m2=10), and the interval between electrodes is 100 μm. There are 80 electrodes in total (m=80), and the size of each electrode is 14 mm×100 μm×150 nm in length×width×thickness.

④ Shape and size of column signal electrodes: 8 rectangular strip electrodes (m3=8), the interval between the strips is 2mm, and the size of each electrode is 14mm×2mm×150nm in length×width×thickness.

The circuit design of the optical switch gating (scanning) control device adopts 4 sets of 4×4 double-layer structure liquid crystal light switch control circuits, and performs serial and parallel control on the 8×8 double-layer structure liquid crystal light switch array. Each set uses 5 pieces of high-speed 16-way multiplexing circuit CD74HC4067 as the row and column gating (scanning) circuit, 1 piece of 8-way multiplexing circuit CD74HC4051 as the row and column signal electrode control circuit, and 22 pieces of 4 op amps MAX419 to build the holding circuit. The optical switch gating (scanning) controller adopts STM32F107 with 32-bit ARMCortex-M3 structure. The principle of a single control circuit is shown in Figure 11.

The grating device adopts an 8×8 double-structure grating array device, see Fig. 2 and Fig. 3 . The basic parameters are as follows:

①Fine grating: The wavelength of the commonly used laser light source is about λ=1μm. Considering the elimination of side lobes, d<λ should be satisfied, and d<<λ should be satisfied to improve efficiency and precision. Take a=100nm, b=100nm, d= 200nm.

②Coarse grating: Considering that the outer diameter of the current laser device package is at least about 4mm, take A=2mm, B=2mm, D=A+B=2+2=4mm, corresponding to the outer diameter of the laser diode device should be smaller than D, Otherwise, the device cannot be installed and positioned. The outer diameter of the laser diode device is φ3.5mm in the application example of the present invention.

Therefore, in the square light-transmitting grid with A=2mm, the light and dark structures are evenly arranged and distributed, as shown in FIG. 3 , which is a partially enlarged view. The light-transmitting hole is a circle with a diameter equal to a=100nm (the smaller the aperture, the better the diffraction effect), and the distance between the two light-transmitting holes is b=100nm. 10000×10000=1×10 ⁸ light-transmitting round holes are evenly distributed within the range of 2mm×2mm, forming a surface grating structure in which longitudinal gratings and horizontal gratings are combined.

③ Dimensions and materials: According to the structural dimensions of the coarse grating, the outer dimensions of the double-structure grating are determined to be 32mm×32mm×4mm in length×width×thickness, and the material is made of optical K9 glass.

The laser reflection signal processing device is shown as 5 in Figure 1. It is composed of InGaAs (InGaAs) avalanche diode array detector and microcontroller. 1G, 1.5G, 2.5G optional, nanosecond response, short wave can be extended to 400nm ~ 1800nm, 12V power supply.

Optical system selection. A collimating lens with a long focal length is selected as the illuminating lens, and a focusing lens with a short focal length is used as the receiving lens.

An optical phased array laser radar device according to the present invention consists of six parts: a laser array light source, a double-layer structure liquid crystal optical switch array, an optical switch scanning control device, a double-structure grating array device, a laser reflection signal processing device, and an optical lens group. The laser array is used as the irradiation light source of the system to provide multi-beams and parallel laser beams distributed in a planar array. The double-layer structure liquid crystal optical switch array and the optical switch gating (scanning) control device pass the time-delay gating of the optical switch between the beams and The beam itself undergoes relative phase modulation, and the double-structure grating array device uses its unique diffraction nesting and space synchronization interference characteristics to generate various steering angles and far-field illumination modes with adjustable depth focus in the distance direction, and performs optical phased array on the target. Scanning irradiation, the laser diode array element of the laser array, the optical window array element of the liquid crystal optical switch array (itself is an array) and the array element of the double-structure grating array coarse grating (itself also an array), the number and interval size are the same One-to-one correspondence and consistency, the laser reflection signal processing device receives and processes the laser signal reflected back from the target, and calculates the information parameters such as distance, orientation, speed, etc. The beam is corrected.

Claims (10)

1. An optical phased array laser radar apparatus, characterized in that: the double-structure grating array laser comprises a laser array light source, a double-layer structure liquid crystal optical switch array, a double-structure grating array device, an optical switch scanning control device, a laser reflection signal processing device and an optical lens, wherein the optical lens comprises a scanning irradiation lens and a target reflection receiving lens which are respectively arranged between the double-structure grating array device and an irradiation target and between the irradiation target and the laser reflection signal processing device and are respectively used for correcting emergent light beams and incident light beams;

the laser array light source is used as an irradiation light source of the system to provide multiple beams and parallel laser beams distributed in a planar array;

the double-structure grating array device is formed by embedding a light-transmitting array element part of an array coarse grating into a fine grating, so that the diffraction nesting and space synchronous interference characteristics of the double-structure grating array device generate various steering angles and far-field irradiation modes with adjustable irradiation intensity in the distance direction;

under the control of the optical switch scanning control device, the beams emitted by the laser array light source are subjected to related phase modulation between the beams and the beams per se through the delayed gating of the double-layer structure liquid crystal optical switch array, and are combined with a double-structure grating array device to finish optical phased array scanning irradiation on a target;

the laser reflection signal processing device receives and processes laser signals reflected by a target and calculates distance, direction and speed information parameters.

2. The optical phased array lidar apparatus of claim 1, wherein: the double-structure grating array device comprises n multiplied by m light-transmitting windows, the light-transmitting windows are distributed in a black-and-white alternating arrangement mode according to n lines multiplied by m rows of rectangles, black parts are opaque, white parts are transparent, the width of any light-transmitting unit is equal to the width of the adjacent opaque unit, the sum of the width of any light-transmitting unit and the width of the adjacent opaque unit is the unit interval of the unit when the unit is subjected to phase modulation, and therefore the device body with n lines multiplied by m rows of rectangles is formed, the light-transmitting windows are independent area array gratings, s multiplied by s transparent round holes are uniformly distributed in the area array gratings, the unit interval of the area array gratings is recorded as D, the D is integral multiple of D, and the n, m, s, D and D are positive integers.

3. The optical phased array lidar apparatus according to claim 2, wherein: when the double-structure grating array device is used, each light-transmitting unit of the array corresponds to one laser diode light source and one phase modulation window respectively, the wavelength of the laser diode light source is lambda, and d is not more than 1/2 lambda.

4. The optical phased array lidar apparatus of claim 1, wherein: the double-layer structure liquid crystal optical switch array comprises a first layer liquid crystal panel and a second layer liquid crystal panel which are arranged up and down, wherein a first orientation film, a line scanning electrode, an upper glass plate and an upper polaroid are sequentially arranged on the first layer liquid crystal panel in parallel, and a second orientation film, a line signal electrode and a middle glass plate are sequentially arranged below the first layer liquid crystal panel in parallel;

a third oriented film and a column scanning electrode are sequentially arranged on the upper surface of the second layer of liquid crystal panel in parallel, and a fourth oriented film, a column signal electrode, a lower layer glass panel and a lower polarizing plate are sequentially arranged on the lower surface of the second layer of liquid crystal panel in parallel; the row scanning electrodes and the row signal electrodes are vertical to each other and are aligned in an up-and-down covering manner, the column signal electrodes and the row signal electrodes are vertical to each other and are aligned in an up-and-down covering manner, and the column scanning electrodes and the column signal electrodes are vertical to each other and are aligned in an up-and-down covering manner; the first oriented film, the second oriented film, the third oriented film and the fourth oriented film are all made of a thin layer of high molecular organic matter, and are subjected to oriented friction treatment to enable rod-shaped liquid crystal molecules to be parallel to the surface of the glass and to be arranged along the direction of the oriented treatment, so that the molecular orientation of the upper surface of the crystal of each layer of liquid crystal panel is perpendicular to the molecular orientation of the lower surface of the crystal.

5. The optical phased array lidar apparatus of claim 4, wherein: n line scanning electrodes are uniformly divided into n1 groups, and n2 line scanning electrodes are arranged in each group, so that n = n1 × n2; the width and the interval of the electrodes in each group are distributed in an equal size, and the width and the interval of each group are distributed in an equal size;

m column scanning electrodes are uniformly divided into m1 groups, and m2 column scanning electrodes are arranged in each group, so that m = m1 × m2; the width and the interval of the electrodes in each group are distributed in an equal size, and the width and the interval of each group are distributed in an equal size;

the n groups of row scanning electrodes correspond to n3 row signal electrodes, and the m groups of column scanning electrodes correspond to m3 column signal electrodes.

6. The optical phased array lidar apparatus of claim 1, wherein: the optical switch scanning control device comprises a holding circuit, a gating circuit, an optical switch gating controller and an independent controllable voltage-stabilized power supply; the control output end of the optical switch gating controller is connected with the input end of the gating circuit, and the output end of the gating circuit is connected with electrodes in the switch array to be controlled through the holding circuit; the independent controllable voltage-stabilized power supply is used for supplying power to the holding circuit, the gating circuit and the optical switch gating controller; the holding circuit is composed of a plurality of holding units with the same structure, and comprises a row/column signal holding circuit, a column scanning holding circuit and a row scanning holding circuit; the gate circuit comprises a row/column signal gate circuit, a column scanning gate circuit and a row scanning holding circuit which are formed by a plurality of gate units with the same structure.

7. The optical phased array lidar apparatus according to claim 6, wherein: the holding circuit comprises a peripheral circuit formed by an operational amplifier MAX419 and a capacitor; the gating circuit adopts a high-speed CMOS multiplexing circuit CA74HC4051 or adopts CA74HC4067 to save the number of used chips.

8. An optical phased array lidar apparatus according to claim 1, wherein: the laser array light source is formed by arranging n rows of light array elements on an expandable frame in an x m-column manner, the light array elements are independently packaged individuals and comprise pressing rings, collimating lenses, adjusting gaskets, laser diodes, a front-mounted driving circuit, a socket, a metal shell and organic silica gel, and the socket is fixed at one end of the metal shell and connected with the front-mounted driving circuit; a laser diode packaged by the heat sink is fixed in the middle position in the metal shell, and a pin of the laser diode is connected with the output end of the front driving circuit and is encapsulated by organic silica gel; the collimating lens is fixedly arranged at the other end in the metal shell through an adjusting gasket and a pressing ring respectively;

the expandable frame comprises an upper fixing partition plate and a lower fixing partition plate which are arranged in parallel, n rows of x m columns of array elements are vertically arrayed between the upper fixing partition plate and the lower fixing partition plate, the array elements are parallel to each other, the socket end is arranged at the lower end, the intervals between the array elements are uniform and consistent, the intervals are filled with potting materials, the potting materials are mixtures of aluminum powder and silica gel, and the whole array light source is also encapsulated while the potting materials are filled;

the driving circuit comprises a filter circuit and a driving and brightness control circuit, wherein the input end of the filter circuit is connected with the output end of the socket, the output end of the filter circuit is connected with the input end of the driving and brightness control circuit, and the output end of the driving and brightness control circuit is connected with a corresponding pin of the laser diode.

9. The optical phased array lidar apparatus according to any of claims 1-8, wherein: the n multiplied by m laser array light source corresponds to an optical switch array with n multiplied by m light-passing windows and a double-structure grating array device with n multiplied by m coarse grating array elements, a corresponding light source array element, one optical switch light-passing window and one coarse grating array element of the double-structure grating array form a micro optical phased array irradiation channel, the n multiplied by m micro optical phased array irradiation channels work cooperatively according to a certain sequence and phase difference to form an integral laser radar scanning irradiation working mode based on the optical phased array technology, and a reflection signal of a target to irradiated laser is received by an avalanche photodiode device and related information parameters are resolved by a microcontroller.

10. The optical phased array lidar apparatus of claim 9, wherein: the liquid crystal optical switch array with the double-layer structure adopts a sequential gating and maintaining working mode, specifically different requirements on driving signals aiming at different scanning working modes are different, wherein the corresponding driving signal characteristics and time sequence requirements are designed aiming at three gating working modes of linear scanning, sector scanning and deep focusing as follows:

(1) linear scanning: the delay time is fixed or changed regularly, the amplitude of the driving signal is fixed, all elements are selected one by one, and only one element is selected at any time;

(2) sector scanning: the delay time is changed according to the fan-scanning rule, the amplitude of the driving signal is constant, all elements are gated item by item, and the elements gated in the early stage are kept gated subsequently;

(3) irradiation intensity control: the delay time is changed regularly, the amplitude of the driving signal is changed regularly, the elements are gated item by item, and the elements gated in the early stage are kept gated subsequently.

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