阅读说明：本技术 一种多波束相干探测激光雷达 (Multi-beam coherent detection laser radar ) 是由 夏海云 裘家伟 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种多波束相干探测激光雷达,包括种子光激光器、第一多通道光纤分束器、声光调制器、第一脉冲光纤放大器、第二多通道光纤分束器、第二脉冲光纤放大器、环行器、多波束收发望远镜、光纤合束器、平衡探测器与多通道模拟采集卡；本发明采用大视场多线激光输出,可同时探测N个视场的目标距离、仰角、方位、速度和风场；采用大视场角的激光多线输出,在保障探测距离的同时增大了探测视场角范围；搭配水平扫描装置,可以实现高速三维空间风场和目标探测；采用单台种子光激光器驱动N台激光放大器的方法,节省了多台种子光激光器的成本。(The invention discloses a multi-beam coherent detection laser radar, which comprises a seed light laser, a first multi-channel optical fiber beam splitter, an acousto-optic modulator, a first pulse optical fiber amplifier, a second multi-channel optical fiber beam splitter, a second pulse optical fiber amplifier, a circulator, a multi-beam transceiver telescope, an optical fiber beam combiner, a balance detector and a multi-channel analog acquisition card, wherein the seed light laser is connected with the first multi-channel optical fiber beam splitter; the invention adopts large-view-field multi-line laser output, and can simultaneously detect the target distance, elevation angle, azimuth, speed and wind field of N view fields; the laser multi-line output with a large field angle is adopted, so that the detection field angle range is enlarged while the detection distance is ensured; the horizontal scanning device is matched, so that high-speed three-dimensional space wind field and target detection can be realized; the method of driving N laser amplifiers by using a single seed optical laser saves the cost of a plurality of seed optical lasers.)

1. The utility model provides a multi-beam coherent detection laser radar, includes seed light laser instrument A, first multichannel fiber optic splitter B, acoustic optical modulator C, first pulse fiber amplifier D, second multichannel fiber optic splitter E, second pulse fiber amplifier F, circulator G, multi-beam transceiver telescope H, optic fibre beam combiner I, balanced detector J and multichannel analog acquisition card K, its characterized in that: the light source point of the seed light laser A is connected with the input end of a first multi-channel optical fiber beam splitter B through optical fibers, the output end of the first multi-channel optical fiber beam splitter B is respectively connected with the input end of an acousto-optic modulator C and the input end of an optical fiber beam combiner I, the signal output end of the acousto-optic modulator C is connected with the signal input end of a first pulse optical fiber amplifier D through optical fibers, the signal output end of the first pulse optical fiber amplifier D is connected with the signal input port of a second multi-channel optical fiber beam splitter E through optical fibers, the output port of the multi-channel optical fiber beam splitter E is connected with the input ports of N second pulse optical fiber amplifiers F through optical fibers, the output ports of the N second pulse optical fiber amplifiers F are respectively connected with the first ports of N circulators G through optical fibers, and the second ports of the N circulators G are connected with a multi-beam transceiver H through optical fibers, the third ports of the N circulators G are connected with the input port of the optical fiber beam combiner I through optical fibers, the output port of the optical fiber beam combiner I is connected with the input end of the balance detector J through optical fibers, and the output end of the balance detector J is connected with the multi-channel analog acquisition card K through an electric signal.

2. The multibeam coherent detection lidar of claim 1, wherein: the multi-beam transceiver telescope H forms a sector space laser linear array.

3. The multibeam coherent detection lidar of claim 1, wherein: the modulation result of the acousto-optic modulator C is pulse light.

4. The multibeam coherent detection lidar of claim 1, wherein: the wavelength output by the seed light laser A can be ultraviolet light, visible light or infrared light.

5. The multibeam coherent detection lidar of claim 1, wherein: the optical fiber coupled with the multi-beam transceiver telescope H is a multimode optical fiber.

6. A multibeam coherent detection lidar according to claims 1-5, wherein the apparatus is operable to comprise the steps of:

step 1, generating single-mode narrow-linewidth frequency-stabilized continuous light by a seed light laser A;

step 2, dividing the single-mode narrow-linewidth frequency-stabilized continuous light into 1+ N narrow-linewidth frequency-stabilized continuous light with equal power by a first multi-channel optical fiber beam splitter B;

step 3, enabling 1 beam of narrow-line-width frequency-stabilized continuous light after the uniform division of the first multi-channel beam splitter B to enter an acousto-optic modulator C, and obtaining pulsed light through modulation of the acousto-optic modulator C;

step 4, leading the pulse light into a first pulse optical fiber amplifier D through an optical fiber, and performing power amplification through the first pulse optical fiber amplifier D to obtain first power amplification pulse light;

step 5, the first power amplification pulse light is equally divided through a second multi-channel optical fiber beam splitter E to obtain N pulse light with equal power;

step 6, the N pulse lights with equal power flow to the corresponding second pulse optical fiber amplifiers F respectively and independently, and the split pulse lights flowing in the pulse light amplifiers are amplified again through the corresponding second pulse optical fiber amplifiers F to obtain secondary power amplification pulse lights;

step 7, leading the N strands of second power amplification pulse light into a corresponding circulator G through an optical fiber, and carrying out unidirectional isolation on the second power amplification pulse light by the circulator G;

step 8, a second port of the circulator G guides the second power amplification pulse light to the multi-beam transceiver telescope H through the optical fiber, then the second power amplification pulse light array is transmitted through the multi-beam transceiver telescope H, and the reflected pulse light is received;

9, returning and feeding back the reflected pulse light to the circulator G through the multimode fiber, and then leading out the reflected pulse light through a third port of the circulator G to obtain feedback pulse light;

step 10, feeding back pulse light into an optical fiber beam combiner I through optical fibers, and simultaneously leading N beams of narrow-linewidth frequency-stabilized continuous light equally divided by a first multi-channel optical fiber beam splitter B in step 2 into the optical fiber beam combiner I through the optical fibers;

step 11, the optical fiber beam combiner I performs mutual interference on the feedback pulse light and the narrow-linewidth frequency-stabilized continuous light, and then guides the obtained combined beam interference light to a balance detector J;

step 12, detecting the combined interference light by a balance detector J to obtain a pulse electric signal;

and step 13, leading the pulse electrical signal into a multi-channel analog acquisition card K by the balance detector J for signal data acquisition.

Technical Field

The invention relates to the technical field of laser radars, in particular to a multi-beam coherent detection laser radar.

Background

The laser radar has the advantages of good directivity, high time resolution and spatial resolution, high precision, non-contact (remote sensing) detection and the like, and is applied to the fields of speed measurement, imaging, pollutant monitoring, wind measurement, temperature measurement, density detection and the like. The coherent laser radar adopts a heterodyne detection mode, a backward scattering signal is amplified through local oscillation light, and the signal-to-noise ratio can reach the quantum limit theoretically. The coherent radar requires the wave-front matching of the local oscillator light and the signal light, so that the coherent laser radar can inhibit background noise and detector noise, and can realize continuous observation under the condition without a filter. Compared with a direct wind lidar, the coherent radar does not need an optical frequency discriminator, has a simple receiving light path and is insensitive to temperature gradient and stress gradient.

Research work on coherent Doppler laser radars has been widely conducted at home and abroad. Representatively, rockschidmann and american coherent technology corporation (LMCT) have been working on the research of coherent doppler wind lidar. In 2002, LMCT issued a 2 μm-based WindTracer commercial coherent doppler wind lidar system. WindTracer has been upgraded to a 1.617 μm based Er: YAG laser. NASA used a commercial WindTracer system for aircraft wind trimming, clear sky turbulence, etc. detection, and modeled and predicted aircraft vortices at denver international airports in 2009. NASA uses a commercial winddracer system for aircraft wind shear, clear sky turbulence, etc. detection and modeling and prediction of aircraft vortices in denver international airport in 2009. In 2012, Mitsubishi corporation of Japan uses Er, Yb: Glass planar waveguide technology and uses secondary laser amplification technology to amplify the output power of the emitted laser, thereby realizing horizontal wind field detection exceeding 30 km. In 2015, ONERA achieved wind field detection at 16km by using multiple fiber amplifiers in parallel to increase the laser pulse energy of the fiber laser to 500 μ J.

In 2011, a 1.55-micrometer all-fiber coherent Doppler wind measurement laser radar system is reported by a Zhongding-rich task group of technical and physical institute (SITP) (209 institute) in southwest China, so that wind field measurement within a height range of 5-200 m is realized, and comparison with wind measurement tower data in a test base is performed. In 2017, the first coherent doppler wind lidar which can simultaneously observe the atmospheric depolarization ratio and the atmospheric wind field in the world was successfully developed by the summer sea cloud topic group of the university of science and technology in China.

However, the performance of the currently commercially used doppler laser radar still has many defects, such as small field angle, incapability of realizing three-dimensional wind field detection, incapability of detecting a target and the like. The coherent laser radar for simultaneously detecting the wind field and the target with large visual field detection capability is required for detecting the atmospheric wind field and the high-speed target which change at high speed.

Disclosure of Invention

The present invention is directed to a multi-beam coherent detection lidar for solving the above-mentioned problems of the prior art.

In order to achieve the purpose, the invention provides the following technical scheme:

a multi-beam coherent detection laser radar comprises a seed light laser, a first multi-channel optical fiber beam splitter, an acousto-optic modulator, a first pulse optical fiber amplifier, a second multi-channel optical fiber beam splitter, a second pulse optical fiber amplifier, a circulator, a multi-beam transceiver telescope, an optical fiber beam combiner, a balance detector and a multi-channel analog acquisition card, wherein a light source point of the seed light laser is connected with the input end of the first multi-channel optical fiber beam splitter through optical fibers, the output end of the first multi-channel optical fiber beam splitter is respectively connected with the input end of the acousto-optic modulator and the input end of the optical fiber beam combiner, the signal output end of the acousto-optic modulator is connected with the signal input end of the first pulse optical fiber amplifier through optical fibers, the signal output end of the first pulse optical fiber amplifier is connected with the signal input end of the second multi-channel optical fiber beam splitter through optical fibers, and the output end of the multi-channel optical fiber beam splitter is connected with the input ends of N second pulse optical fiber amplifiers through optical fibers The output ports of the N second pulse optical fiber amplifiers are respectively connected with the first ports of the N circulators through optical fibers, the second ports of the N circulators are connected with the multi-beam transceiver telescope through optical fibers, the third ports of the N circulators are connected with the input port of the optical fiber beam combiner through optical fibers, the output port of the optical fiber beam combiner is connected with the input end of the balance detector through optical fibers, and the output end of the balance detector is connected with the multi-channel analog acquisition card through an electric signal.

Preferably, the multi-beam transceiver telescope forms a sector space laser linear array.

Preferably, the modulation result of the acousto-optic modulator is pulsed light.

Preferably, the wavelength output by the seed light laser can be ultraviolet light, visible light or infrared light.

Preferably, the optical fiber coupled with the multi-beam transceiver telescope is a multimode optical fiber.

Based on a multi-beam coherent detection laser radar, the device work flow comprises the following steps:

step 1, generating single-mode narrow-linewidth frequency-stabilized continuous light by a seed light laser;

step 2, dividing the single-mode narrow-linewidth frequency-stabilized continuous light into 1+ N narrow-linewidth frequency-stabilized continuous light with equal power by a first multi-channel optical fiber beam splitter;

step 3, enabling 1 beam of narrow-linewidth frequency-stabilized continuous light after the uniform division of the first multi-channel beam splitter to enter an acousto-optic modulator C, and obtaining pulsed light through modulation of the acousto-optic modulator C;

step 4, leading the pulse light into a first pulse optical fiber amplifier through an optical fiber, and performing power amplification through the first pulse optical fiber amplifier to obtain first power amplification pulse light;

step 5, the first power amplification pulse light is equally divided through a second multi-channel optical fiber beam splitter to obtain N pulse light with equal power;

step 6, the N pulse lights with equal power flow to the corresponding second pulse optical fiber amplifiers respectively and independently, and the split pulse lights flowing in the pulse light amplifiers are amplified again through the corresponding second pulse optical fiber amplifiers to obtain secondary power amplification pulse lights;

step 7, leading the N strands of second power amplification pulse light into a corresponding circulator through an optical fiber, and carrying out unidirectional isolation on the second power amplification pulse light by the circulator;

step 8, a second port of the circulator guides the second power amplification pulse light to a multi-beam transceiver telescope through an optical fiber, then the second power amplification pulse light array is transmitted through the multi-beam transceiver telescope, and the reflected pulse light is received;

9, returning and feeding back the reflected pulse light to the circulator through the multimode fiber, and then leading out the reflected pulse light through a third port of the circulator to obtain feedback pulse light;

step 10, feeding back pulse light to enter the optical fiber beam combiner through optical fibers, and simultaneously leading N beams of narrow-linewidth frequency-stabilized continuous light equally divided by the first multi-channel optical fiber beam splitter in the step 2 into the optical fiber beam combiner through the optical fibers;

step 11, the optical fiber beam combiner performs mutual interference on the feedback pulse light and the narrow-linewidth frequency-stabilized continuous light, and then guides the obtained combined beam interference light to a balance detector;

step 12, detecting the combined interference light by a balance detector to obtain a pulse electric signal;

and step 13, leading the pulse electric signals into a multi-channel analog acquisition card by the balance detector to acquire signal data.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention adopts large-view-field multi-line laser output, and can simultaneously detect the target distance, elevation angle, azimuth, speed and wind field of N view fields;

2. the invention adopts the laser multi-line output with a large field angle, thereby ensuring the detection distance and simultaneously enlarging the detection field angle range;

3. the invention can realize high-speed three-dimensional space wind field and target detection by matching with a horizontal scanning device;

4. the invention adopts the method that a single seed optical laser drives N laser amplifiers, thereby saving the cost of a plurality of seed optical lasers.

Drawings

FIG. 1 is a system block diagram of the present invention.

In the figure: the system comprises a seed light laser-A, a first multi-channel optical fiber beam splitter-B, an acousto-optic modulator-C, a first pulse optical fiber amplifier-D, a second multi-channel optical fiber beam splitter-E, a second pulse optical fiber amplifier-F, a circulator-G, a multi-beam transceiver telescope-H, an optical fiber beam combiner-I, a balance detector-J and a multi-channel analog acquisition card-K.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Examples

Referring to fig. 1, the present invention provides a technical solution: a multi-beam coherent detection laser radar comprises a seed light laser A, a first multi-channel optical fiber beam splitter B, an acousto-optic modulator C, a first pulse optical fiber amplifier D, a second multi-channel optical fiber beam splitter E, a second pulse optical fiber amplifier F, a circulator G, a multi-beam transceiver telescope H, an optical fiber beam combiner I, a balance detector J and a multi-channel analog acquisition card K, wherein a light source point of the seed light laser A is connected with the input end of the first multi-channel optical fiber beam splitter B through an optical fiber, the output end of the first multi-channel optical fiber beam splitter B is respectively connected with the input end of the acousto-optic modulator C and the input end of the optical fiber beam combiner I, the signal output end of the acousto-optic modulator C is connected with the signal input end of the first pulse optical fiber amplifier D through an optical fiber, and the signal output end of the first pulse optical fiber amplifier D is connected with the signal input port of the second multi-channel optical fiber beam splitter E through an optical fiber, the output port of the multichannel optical fiber beam splitter E is connected with the input ports of N second pulse optical fiber amplifiers F through optical fibers, the output ports of the N second pulse optical fiber amplifiers F are respectively connected with the first ports of N circulators G through optical fibers, the second ports of the N circulators G are connected with the multi-beam transceiver telescope H through optical fibers, the third ports of the N circulators G are connected with the input port of an optical fiber beam combiner I through optical fibers, the output port of the optical fiber beam combiner I is connected with the input end of a balance detector J through optical fibers, and the output end of the balance detector J is connected with the multichannel analog acquisition card K through an electric signal.

Specifically, the multi-beam transceiver telescope H forms a sector spatial laser line array.

Specifically, the modulation result of the acousto-optic modulator C is pulsed light, and the modulation is coded quasi-continuous pulsed light in this embodiment.

Specifically, the wavelength output by the seed light laser a may be ultraviolet light, visible light, or infrared light.

Specifically, the optical fiber coupled to the multi-beam transceiver telescope H is a multimode optical fiber.

Based on a multi-beam coherent detection laser radar, the device work flow comprises the following steps:

step 1, generating single-mode narrow-linewidth frequency-stabilized continuous light by a seed light laser A;

step 2, dividing the single-mode narrow-linewidth frequency-stabilized continuous light into 1+ N narrow-linewidth frequency-stabilized continuous light with equal power by a first multi-channel optical fiber beam splitter B;

step 3, enabling 1 beam of narrow-line-width frequency-stabilized continuous light after the uniform division of the first multi-channel beam splitter B to enter an acousto-optic modulator C, and obtaining pulsed light through modulation of the acousto-optic modulator C;

step 4, leading the pulse light into a first pulse optical fiber amplifier D through an optical fiber, and performing power amplification through the first pulse optical fiber amplifier D to obtain first power amplification pulse light;

step 5, the first power amplification pulse light is equally divided through a second multi-channel optical fiber beam splitter E to obtain N pulse light with equal power;

step 6, the N pulse lights with equal power flow to the corresponding second pulse optical fiber amplifiers F respectively and independently, and the split pulse lights flowing in the pulse light amplifiers are amplified again through the corresponding second pulse optical fiber amplifiers F to obtain secondary power amplification pulse lights;

step 7, leading the N strands of second power amplification pulse light into a corresponding circulator G through an optical fiber, and carrying out unidirectional isolation on the second power amplification pulse light by the circulator G;

step 8, a second port of the circulator G guides the second power amplification pulse light to the multi-beam transceiver telescope H through the optical fiber, then the second power amplification pulse light array is transmitted through the multi-beam transceiver telescope H, and the reflected pulse light is received;

9, returning and feeding back the reflected pulse light to the circulator G through the multimode fiber, and then leading out the reflected pulse light through a third port of the circulator G to obtain feedback pulse light;

step 10, feeding back pulse light into an optical fiber beam combiner I through optical fibers, and simultaneously leading N beams of narrow-linewidth frequency-stabilized continuous light equally divided by a first multi-channel optical fiber beam splitter B in step 2 into the optical fiber beam combiner I through the optical fibers;

step 11, the optical fiber beam combiner I performs mutual interference on the feedback pulse light and the narrow-linewidth frequency-stabilized continuous light, and then guides the obtained combined beam interference light to a balance detector J;

step 12, detecting the combined interference light by a balance detector J to obtain a pulse electric signal;

and step 13, leading the pulse electrical signal into a multi-channel analog acquisition card K by the balance detector J for signal data acquisition.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The standard parts used in the invention can be purchased from the market, the special-shaped parts can be customized according to the description of the specification and the accompanying drawings, the specific connection mode of each part adopts conventional means such as mature bolts, rivets, welding and the like in the prior art, the machines, the parts and equipment adopt conventional models in the prior art, and the circuit connection adopts the conventional connection mode in the prior art, so that the detailed description is omitted.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.