CN108693540A - Phased-array laser radar - Google Patents

Abstract

The present invention relates to a kind of phased-array laser radars, including:Laser generator, for generating original laser;Optical transmission medium;Light distributor, the smooth distributor connect the laser generator by optical transmission medium;The smooth distributor includes the device for receiving the original laser;And Z radiating element, each radiating element are connected with the smooth distributor respectively;Wherein, Z is the natural number more than 1;Wherein, light distributor is used to original laser being assigned as the first optical signal of the roads Z, and will be respectively sent to each radiating element per the first optical signal all the way, so that the electromagnetic wave of all radiating elements radiation synthesizes a branch of radar wave;The material of laser generator, device and optical transmission medium be can transimission power be more than setting performance number laser material.Above-mentioned phased-array laser radar can improve the input power of phased-array laser radar, and then improve the general power of the radar wave of all radiating element synthesis.

Description

Phased Array LiDAR

technical field

The invention relates to the technical field of laser radar, in particular to a phased array laser radar.

Background technique

LiDAR is a sensor that uses laser light to detect and measure distances. Its principle is similar to that of radar and sonar, that is, the transmitting device emits laser pulses to the target, and the receiving device measures the delay and intensity of the return pulse to measure the distance and reflectivity of the target. Traditional lidars use mechanical rotating devices to achieve 360-degree spatial scanning, but such radars use bulky mechanical devices, and at the same time, the scanning rate is slow. Once the mechanical rotating devices fail, it is difficult to continue normal use.

In order to solve these problems, phased array lidar came into being. Phased array lidar consists of many identical antennas forming a matrix, and the radiation waves of all antennas form a radar wave through interference in the far field. An electronic system controls the phase of each antenna in real time, thereby controlling the direction of the radar wave in the far field. By changing the phase of certain antennas, the electronic system can change the direction of the radar wave, thus realizing dynamic scanning. Such electronic scanning does not require a mechanical rotating device, the scanning rate is fast, and even if a small number of antennas fail, it will not affect the actual use of the phased array lidar. However, it is difficult for the traditional phased-array lidar to achieve higher transmission power, so how to increase the transmission power of the phased-array lidar is an urgent problem to be solved.

Contents of the invention

Based on this, it is necessary to provide a phased array laser radar for the problem of how to increase the transmission power of the phased array laser radar.

A phased array lidar, comprising:

a laser generator for generating raw laser light;

optical transmission medium;

A light distribution device, the light distribution device is connected to the laser generator through an optical transmission medium; the light distribution device includes a device for receiving the original laser light; and

Z radiation units, each of which is connected to the light distribution device; wherein, Z is a natural number greater than 1;

Wherein, the light distributing device is used to distribute the original laser light into Z channels of first-type optical signals, and send each of the first-type optical signals to each of the radiation units, so that all of the radiation The electromagnetic wave radiated by the unit synthesizes a radar wave; the materials of the laser generator, the device and the optical transmission medium are materials capable of transmitting laser with a power greater than a set power value.

In one embodiment, the condition that the set power value satisfies is: the phased array laser radar can use the original laser with the power of the set power value to detect the target whose distance is greater than the set distance value.

In one of the embodiments, the set power value is greater than 10W.

In one of the embodiments, the material of the laser generator, the device and the optical transmission medium is SiN.

In one of the embodiments, the phase modulation efficiency of the material of the radiation unit is greater than a set efficiency threshold.

In one of the embodiments, the material of the radiation unit is Si.

In one of the embodiments, the light distribution device includes:

A first light distribution unit, the first light distribution unit is connected to the laser generator through the optical transmission medium; the material of the first light distribution unit is a material capable of transmitting laser light with a power greater than a set power value; and

M second light distribution units, each of the second light distribution units is connected to the first light distribution unit, and the second light distribution unit is connected to N radiation units; the M and N are natural numbers , and M×N=Z; the first optical distribution unit distributes the original laser light into M channels of second-type optical signals, and sends each second-type optical signal to the corresponding second optical distribution unit unit; the second optical distribution unit distributes the second type of optical signal into N channels of the first type of optical signal, and sends each channel of the first type of optical signal to the corresponding radiation unit.

In one of the embodiments, the first light distribution unit and the second light distribution unit are optical couplers or optical beam splitters.

In one of the embodiments, the light distribution device further includes M phase adjusters; each of the phase adjusters is connected between the first light distribution unit and each of the second light distribution units; the phase The adjuster is used to adjust the phase of the second type of optical signal, and send the phase-modulated second type of optical signal to the corresponding second optical distribution unit.

In one of the embodiments, in the phased array lidar, the phase modulation efficiency of the materials of the structures located on the optical path behind the first light distribution unit along the transmission direction of the original laser light is greater than the set efficiency threshold.

In the above-mentioned phased array laser radar, the optical distribution device distributes the original laser light into the first optical signal of the Z channel, and sends each optical signal of the first optical signal to each radiation unit, so that the electromagnetic waves radiated by all the radiation units are combined into one Therefore, the performance of the transmission optical path of the original laser directly affects the transmission power of the entire phased array laser pointer radar, and in the phased array laser radar, the laser generator and the optical distribution device used to receive the original laser The material of the device and the optical transmission medium is a material that can transmit a laser with a power greater than the set power value, that is, the transmission optical path of the original laser can perform high-power transmission, which can increase the input power of the phased array laser radar, thereby improving all radiation. The total power of the radar waves synthesized by the unit.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain the drawings of other embodiments according to these drawings without creative work.

Fig. 1 is a block diagram of a phased array lidar provided by an embodiment;

FIG. 2 is a schematic structural diagram of an embodiment of the phased array laser radar of the implementation manner shown in FIG. 1 .

Detailed ways

In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the associated drawings. Preferred embodiments of the invention are shown in the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the understanding of the disclosure of the present invention more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terminology used herein in the description of the invention is for the purpose of describing specific embodiments only, and is not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to FIG. 1 , an embodiment provides a phased array laser radar, including a laser generator 100 , an optical transmission medium 400 , an optical distribution device 200 and Z radiation units 300 . The laser generator 100 is connected to the light distribution device 200 through an optical transmission medium 400 . The light distribution device 200 is connected to each radiation unit 300 respectively. Among them, Z is a natural number, and Z>1.

The laser generator 100 is used to generate raw laser light. Among them, the original laser is laser, which needs to have higher power for long-distance lidar. The optical transmission medium 400 is capable of propagating light waves, such as an optical waveguide.

The light distribution device 200 is used to distribute the original laser light into Z channels of first-type optical signals, and send each of the first-type optical signals to each radiation unit 300, so that electromagnetic waves radiated by all radiation units 300 are combined into a radar wave . In other words, the optical distribution device 200 has Z output terminals, and each output terminal is connected to a radiation unit 300 , so that each optical signal of the first type propagates to a different radiation unit 300 through different optical paths. The first type of optical signal refers to the light wave obtained after a certain proportion of power distribution is performed on the original laser.

Wherein, the light distribution device 200 is, for example, an optical coupler or an optical beam splitter, and its function is to distribute the original laser light to each radiation unit 300 . The optical coupler is, for example, a directional coupler (Directional coupler) or a star coupler (Star coupler). The optical beam splitter is, for example, a multi-mode interference optical beam splitter (Multi-mode interferometer, MMI) or a Y-shaped beam splitter. Specifically, the optical distribution device 200 evenly distributes the original laser light to each radiation unit 300 , that is, the energy of each first type optical signal is the same.

The radiation unit 300 can perform phase modulation on the received first optical signal, and radiate corresponding electromagnetic waves. Therefore, by adjusting the phase shift of each radiating unit 300, the phase distribution of electromagnetic waves can be changed, so that electromagnetic waves radiated by all radiating units 300 can be synthesized into a specific radar wave through interference in the far field.

Specifically, the optical transmission medium 400, the light distribution device 200, and the radiation unit 300 can all be manufactured using silicon photonics technology. Silicon photonics technology uses silicon and silicon-based substrate materials as optical media, and manufactures corresponding photonic devices and optoelectronic devices (such as silicon-based light-emitting devices, modulators, detectors, optical waveguide devices, etc.) through integrated circuit technology, and uses These devices excite, process, and manipulate photons to realize their practical applications in the fields of optical communication, optical interconnection, and optical computing.

In addition, the light distribution device 200 includes means for receiving raw laser light. Moreover, the materials of the device, the laser generator 100 and the optical transmission medium 400 are materials capable of transmitting laser light with a power greater than the set power value, for example: the laser generator 100, the optical transmission medium 400 and the optical distribution device 200 need to ensure that they can transmit high power laser. Specifically, the condition that the set power value satisfies is that the phased array laser radar can use the original laser with the set power value to detect the target whose distance is greater than the set distance value. For example: the set power value can at least meet the needs of long-range lidar. Specifically, the set power value is greater than 10W, for example. At this time, the materials of the laser generator 100, the optical transmission medium 400, and the optical distribution device 200 for receiving the original laser light can transmit the laser light with a power greater than 10W. Optionally, the materials of the laser generator 100 , the optical transmission medium 400 , and the optical distribution device 200 for receiving the original laser light are, for example, but not limited to SiN.

Among them, the laser generator 100, the optical transmission medium 400, and the devices used to receive the original laser light in the optical distribution device 200 together constitute the transmission optical path of the original laser light, and the performance of the transmission optical path directly determines the acceptable input power of the phased array laser radar. the size of. For long-distance laser radar, the higher the input power of the laser generator 100, the better, and in this embodiment, the laser generator 100, the optical transmission medium 400 and the devices used to receive the original laser light in the optical distribution device 200 are all It can transmit high-power laser, that is, the transmission optical path of the original laser can pass high-power laser, so that the input power of the phased array laser radar can be increased. As the input power is increased, the total power of the radar waves synthesized by all the radiation units 300 is correspondingly increased, so that the detection distance can be extended.

In one embodiment, the phase modulation efficiency of the material of the radiation unit 300 is greater than a set efficiency threshold. For example, the radiating unit 300 is made of a material with relatively high phase modulation efficiency (such as Si), so that the phase modulation efficiency of the entire phased array lidar can be improved.

Specifically, all radiation units 300 form a planar array. Please refer to FIG. 2 , the light distribution device 200 includes a first light distribution unit 210 and M second light distribution units 220 . The laser generator 100 is connected to the first light distribution unit 210 through an optical transmission medium 400 . The first light distribution unit 210 is respectively connected to the second light distribution units 220 , that is, the first light distribution unit 210 includes one input port and M output ports, and each output port is connected to one second light distribution unit 220 . The second light distribution unit 220 is connected to N radiation units 300 . Both M and N are natural numbers, and M×N=Z. Therefore, the second light distribution unit 220 includes 1 input terminal and N output terminals. If each second light distribution unit 220 is located in a different column, then different second light distribution units 220 are connected to N radiation units located in different columns. 300.

Wherein, the first optical distribution unit 210 distributes the original laser light into M channels of second-type optical signals, and sends each channel of second-type optical signals to corresponding second optical distribution units 220 . The second type of optical signal refers to the light wave obtained after a certain proportion of power is allocated to the original laser. Specifically, the first light distribution unit 210 is, for example, a 1:M optical coupler or a 1:M optical beam splitter. Further, the power of the second optical signal is less than or equal to 1/M times the power of the original laser. Therefore, in this embodiment, the first light distribution unit 210 is a device used to receive the original laser light in the light distribution device 200, and the material of the first light distribution unit 210 is a material capable of transmitting laser light with a power greater than the set power value .

The second optical distribution unit 220 distributes the second type of optical signal into N channels of the first type of optical signal, and sends each channel of the first type of optical signal to corresponding radiation units 300 . Specifically, the second light distribution unit 220 is, for example, a 1:N optical coupler or a 1:N optical beam splitter. Further, the power of the first optical signal is less than or equal to 1/N times the power of the second optical signal, that is, the power of the first optical signal is less than or equal to 1/(M×N) times the power of the original laser .

Specifically, the first light distribution unit 210 and the second light distribution unit 220 are optical couplers or optical beam splitters.

Further, please continue to refer to FIG. 2 , the optical distribution device 200 further includes M phase adjusters 230 . Each phase adjuster 230 is connected between the first light distribution unit 210 and each second light distribution unit 220 . In other words, each output end of the first light distribution unit 210 is connected to a second light distribution unit 220 through a phase adjuster 230 . The phase adjuster 230 is used to adjust the phase of the second type of optical signal, and send the phase-modulated second type of optical signal to the corresponding second optical distribution unit 220 . Therefore, each phase adjuster 230 can simultaneously control the phases of the radiation waves of all the radiation units 300 in a row, so that the efficiency of phase modulation can be improved.

Specifically, the phase adjuster 230 may utilize a thermo-optic effect (Thermo-optic effect) or a plasma-dispersion effect (Plasma-dispersion effect) to perform phase modulation. For example, the phase adjuster 230 can be an optical waveguide controlled by a micro heater or an optical waveguide containing a PN junction. Specifically, the manufacturing material of the phase adjuster 230 is such as but not limited to Si.

Further, in the above-mentioned phased array lidar, the phase modulation efficiency of the materials of each structure located on the optical path behind the first light distribution unit 210 along the transmission direction of the original laser light is greater than the set efficiency threshold. For example: each structure located on the optical path behind the first light distribution unit 210 is made of materials with high phase adjustment efficiency. Specifically, in FIG. 2 , from the phase adjuster 230 to the radiation unit 300 , the phase modulation efficiencies of materials of all structures through which light passes are greater than a set efficiency threshold. After the light respectively passes through the first light distribution unit 210 and the second light distribution unit 220, the light power is respectively less than (1/M) times of the original laser power and 1/(M×N) times of the original laser power, therefore, The structures on the optical path after the first optical distribution unit 210 do not need to use materials capable of transmitting high-power laser light, that is, they can be made of materials different from the first optical distribution unit 210 and the optical transmission medium 400, for example, the phase modulation efficiency is selected Made of higher material, thus improving phase modulation efficiency.

Therefore, the above-mentioned phased array laser radar provided by this embodiment adopts different materials in the front and back two different optical paths, which can not only transmit laser light at high power, but also have the characteristics of large-scale phase modulation, so that long-distance and large-scale LiDAR scanning angle.

Specifically, please continue to refer to FIG. 2 , the radiation unit 300 includes an optical antenna 310 and a phase modulator 320 . Wherein, the phase modulator 320 is used to perform phase modulation on the first type of optical signal from the second optical distribution unit 220 , and transmit the phase-modulated optical signal through the optical antenna 310 . Specifically, the phase modulator 320 can be controlled by the electronic system to adjust the phase of the optical antenna 310 . Optionally, the phase modulator 320 can utilize thermo-optic effect or plasma dispersion effect to perform phase modulation.

Therefore, in the above-mentioned phased array lidar provided in this embodiment, on the premise of including the phase adjuster 230, it is possible to use the phase adjuster 230 to adjust all the optical antennas 310 in a row to emit electromagnetic waves with the same phase, and Different optical antennas 310 in each column can emit electromagnetic waves with different phases through the phase modulator 320 in each radiation unit 300 , so that a high-precision radiation distribution pattern can be generated by interference in the far field.

The various technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the various technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A phased array laser radar, comprising: a laser generator for generating raw laser light; optical transmission medium; A light distribution device, the light distribution device is connected to the laser generator through an optical transmission medium; the light distribution device includes a device for receiving the original laser light; and Z radiation units, each of which is connected to the light distribution device; wherein, Z is a natural number greater than 1; Wherein, the light distributing device is used to distribute the original laser light into Z channels of first-type optical signals, and send each of the first-type optical signals to each of the radiation units, so that all of the radiation The electromagnetic wave radiated by the unit synthesizes a radar wave; the materials of the laser generator, the device and the optical transmission medium are materials capable of transmitting laser with a power greater than a set power value. 2. The phased array laser radar according to claim 1, wherein the condition that the set power value satisfies is: the phased array laser radar can use the original laser whose power is the set power value Detect targets whose distance is greater than the set distance value. 3. The phased array laser radar according to claim 2, wherein the set power value is greater than 10W. 4. The phased array laser radar according to claim 1, characterized in that, the materials of the laser generator, the device and the optical transmission medium are SiN. 5. The phased array laser radar according to any one of claims 1 to 4, wherein the phase modulation efficiency of the material of the radiation unit is greater than a set efficiency threshold. 6. The phased array laser radar according to claim 5, wherein the material of the radiation unit is Si. 7. The phased array laser radar according to claim 5, wherein the light distribution device comprises: A first light distribution unit, the first light distribution unit is connected to the laser generator through the optical transmission medium; the material of the first light distribution unit is a material capable of transmitting laser light with a power greater than a set power value; and M second light distribution units, each of the second light distribution units is connected to the first light distribution unit, and the second light distribution unit is connected to N radiation units; the M and N are natural numbers , and M×N=Z; the first optical distribution unit distributes the original laser light into M channels of second-type optical signals, and sends each second-type optical signal to the corresponding second optical distribution unit unit; the second optical distribution unit distributes the second type of optical signal into N channels of the first type of optical signal, and sends each channel of the first type of optical signal to the corresponding radiation unit. 8. The phased array laser radar according to claim 7, wherein the first light distribution unit and the second light distribution unit are optical couplers or optical beam splitters. 9. The phased array laser radar according to claim 7, wherein the optical distribution device also includes M phase regulators; each of the phase regulators is connected to the first optical distribution unit and each of the phase regulators. between the second optical distribution units; the phase adjuster is used to adjust the phase of the second type of optical signal, and send the phase-modulated second type of optical signal to the corresponding second optical distribution unit. 10. The phased array laser radar according to claim 7, characterized in that, in the phased array laser radar, along the transmission direction of the original laser light, on the optical path after the first light distribution unit The phase modulation efficiency of the material of each structure is greater than a set efficiency threshold.