CN114660622A - Wavelength division multiplexing laser radar integration method and system - Google Patents

Abstract

The invention discloses a wavelength division multiplexing laser radar integration method and a system; the method comprises the steps of outputting continuous multi-wavelength tuning laser by using a multi-wavelength laser; dividing the multi-wavelength tuning laser into local oscillation light and detection light after passing through a beam splitter; the detection light is emitted to the space through the laser emission subsystem; generating an echo signal after the space barrier meets the detection light; receiving echo signals through a laser receiving subsystem, and combining local oscillator light and the echo signals into interference signals; detecting the interference signal by a photoelectric detector to obtain a photoelectric signal; and analyzing the photoelectric signal through a data processor, and obtaining the distance and the speed corresponding to the detection object of each wavelength according to the analysis result. By the method, multi-line distance measurement can be obtained, a solid-state scheme of the laser radar is realized, the reliability and the economy of the laser radar are improved, and the complexity of a system is reduced.

Description

A wavelength division multiplexing laser radar integration method and system

technical field

The invention belongs to the field of laser radar scanning, in particular to a wavelength division multiplexing laser radar integration method and system.

Background technique

Lidar technology has a wide range of application value in the fields of automotive, metrology, and industrial measurement. Compared with TOF radar, FM continuous wave lidar can achieve smaller output power, longer-distance detection, and higher test accuracy. Laser FMCW (FrequencyModulated Continuous Wave), that is, frequency modulated continuous wave. Its principle is shown in Figure 1. The tunable light source outputs a continuous frequency modulation signal. The FM continuous wave is divided into two beams, one as the local oscillator and the other as the measurement light. The measurement light shines on the object to be measured, and a reverse echo is generated. The echo optical path and the local oscillator light obtain the echo time delay through coherent detection technology, that is, the transmission distance. Its schematic diagram is shown in Figure 2. Because the frequency-modulated continuous wave has better coherence. The detection signal and the local oscillator signal generate a beat frequency. The beat frequency signal is processed by a power amplifier, an AD conversion module, and then processed by a data processing module (DSP) to obtain frequency information.

The core components of lidar include light source, space scanning system, detector, signal processing unit, etc. Among them, spatial scanning technology is one of the core technologies of lidar. In order to obtain depth information in three-dimensional space, it is necessary to realize two-dimensional irradiation of laser light. Existing practices are mainly divided into two categories: mechanical and OPA. The first category includes traditional two-dimensional galvanometers, MEMS mirrors, etc.; the second category is divided into two cases, the first is to achieve two-dimensional scanning through phased array design; the second is flash mode, which uses surface light source irradiation, Then use the area array to receive.

Because in vehicle radar, there are extremely high requirements for reliability. However, the reliability design of the above-mentioned first type of solution is difficult due to the existence of moving parts. The first solution in the second category is expected to achieve all-solid-state scanning, but it involves a relatively complex integrated optical design, the process is not yet mature, and the emitting point of the laser is arranged in a lattice, there will be a certain diffraction sidelobe, which will some interference. The second scheme in the second category, sampling area array emission, makes the peak power of a single light source insufficient, limits the longest working distance, and makes coherent detection more difficult.

Therefore, how to make the lidar achieve good spatial scanning, while improving the reliability and economy of the lidar, and reducing the system complexity, has become a key issue in current research.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides a wavelength division multiplexing laser radar integration method and system that solves at least some of the above-mentioned technical problems, and can obtain multi-line distance measurement; at the same time, the present invention also realizes the solid-state solution of the laser radar, which improves the performance of the laser radar. reliability and economy, and reduce system complexity.

On the one hand, an embodiment of the present invention provides a wavelength division multiplexing laser radar integration method, including:

S1. Use multi-wavelength laser to output continuous multi-wavelength tuning laser;

S2, after the multi-wavelength tuned laser is passed through the beam splitter, it is divided into local oscillator light and probe light;

S3. The detection light is emitted into the space through the laser emission subsystem; an echo signal is generated after a space obstacle encounters the detection light;

S4, receiving the echo signal through the laser receiving subsystem, and combining the local oscillator light and the echo signal into an interference signal;

S5, the interference signal is detected by a photodetector to obtain a photoelectric signal;

S6. The photoelectric signal is analyzed by the data processor, and the distance and speed corresponding to the detection object of each wavelength are obtained according to the analysis result.

Further, it also includes:

S7. The data processor corrects the beat frequency signal detected by the photodetector according to the analysis result, so as to obtain a more accurate beat frequency signal.

Further, the tuning method of the multi-wavelength laser includes an internal tuning method and an external tuning method;

The internal tuning method includes: using current or temperature or piezoelectric ceramics to continuously tune the light source;

The external tuning method includes: after the multi-wavelength laser emits a fixed-frequency laser, using a phase modulator to tune the fixed-frequency laser.

Further, the S3 specifically includes:

S31, using a demultiplexer to divide the signal of the detection light into different optical paths according to wavelength;

S32, output the signal of the detection light processed by the S31 to the space through the laser transmitter;

S33. After the space obstacle encounters the signal of the detection light, an echo signal is generated.

Further, the S4 specifically includes:

S41, receiving the echo signal through a laser receiver;

S42, returning the echo signal to the waveguide through a multiplexer;

S43. Combine the echo signal in the waveguide and the local oscillator light to form an interference signal through a beam combiner.

Further, the S5 specifically includes:

S51, sending the interference signal to the photodetector according to the wavelength through a demultiplexer;

S52, the photodetector detects the interference signal to obtain a multi-channel photoelectric signal.

On the other hand, an embodiment of the present invention also provides a wavelength division multiplexing laser radar integrated system, using the above method, the system includes: a multi-wavelength laser, a beam splitter, a laser emission subsystem, a laser receiving subsystem, a combined beamers, photodetectors and data processors;

The multi-wavelength laser is used to output continuous multi-wavelength tuned laser light;

the beam splitter, for dividing the multi-wavelength tuned laser light into local oscillator light and probe light;

the laser emission subsystem, used for emitting probe light into space;

The laser receiving subsystem is used for receiving echo signals generated by space obstacles;

the beam combiner, configured to combine the local oscillator light and the echo signal into an interference signal;

The photodetector is used to detect the interference signal to obtain a photoelectric signal;

The data processor is configured to analyze the photoelectric signal, and obtain the distance and speed corresponding to the detection object of each wavelength according to the analysis result.

Further, the data processor is further configured to correct the beat frequency signal detected by the photodetector to obtain a more accurate lot signal.

Further, the laser emission subsystem includes a demultiplexer and a laser transmitter;

the demultiplexer, for dividing the signal of the detection light into different optical paths according to wavelength;

The laser transmitter is used for outputting the signal of the detection light to the space.

Further, the laser receiving subsystem includes a laser receiver and a combiner;

the laser receiver for receiving the echo signal;

The wave combiner is used for returning the echo signal to the waveguide.

Compared with the prior art, a wavelength division multiplexing laser radar integration method and system described in the present invention has the following beneficial effects:

The invention adopts the wavelength division multiplexing technology to realize the expansion of the optical path output, and emits laser light of different wavelengths in space.

The invention adopts the wavelength division multiplexing technology, which can save the number of components of the radar system and reduce the difficulty of control.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description, claims, and drawings.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

FIG. 1 is a flowchart of a method for integrating a wavelength division multiplexing laser radar according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a working mode of a wavelength division multiplexing laser radar according to Embodiment 1 of the present invention.

FIG. 3 is a schematic diagram of the second working mode of the wavelength division multiplexing laser radar according to Embodiment 1 of the present invention.

FIG. 4 is a schematic diagram of a third working mode of the wavelength division multiplexing laser radar according to Embodiment 1 of the present invention.

FIG. 5 is a schematic diagram of a wavelength division multiplexing laser radar integration method provided in Embodiment 2 of the present invention.

FIG. 6 is a schematic diagram of a wavelength division multiplexing laser radar integration method provided in Embodiment 3 of the present invention.

FIG. 7 is a schematic diagram of a wavelength division multiplexing laser radar integrated system provided by an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be more thoroughly understood, and will fully convey the scope of the present disclosure to those skilled in the art.

Referring to FIG. 1, an embodiment of the present invention provides a wavelength division multiplexing laser radar integration method, which specifically includes the following steps:

S1. Use multi-wavelength laser to output continuous multi-wavelength tuning laser;

S2, after the multi-wavelength tuned laser is passed through the beam splitter, it is divided into local oscillator light and probe light;

S3. The detection light is emitted into the space through the laser emission subsystem; an echo signal is generated after a space obstacle encounters the detection light;

S4, receiving the echo signal through the laser receiving subsystem, and combining the local oscillator light and the echo signal into an interference signal;

S5, the interference signal is detected by a photodetector to obtain a photoelectric signal;

S6, analyze the photoelectric signal by the data processor, and obtain the distance and speed corresponding to the detection object of each wavelength according to the analysis result;

S7. According to the analysis result, the data processor adjusts the beat frequency signal detected by the photodetector, and adjusts the driving and modulation signals of the multi-wavelength laser.

The above steps will be described in detail below.

In the above-mentioned step S1, the multi-wavelength laser used in the embodiment of the present invention may adopt DFB laser arrays of different wavelengths, may be realized by a multilateral belt generated by an EOM, or may be realized by a mode-locked laser splitting a longitudinal mode or the like. The multi-wavelength laser used in the embodiment of the present invention is a narrow linewidth laser; the narrow linewidth laser represents a laser whose output mode is a single longitudinal mode. Usually smaller bandwidth and RIN noise are required.

The tuning methods of multi-wavelength lasers include internal tuning and external tuning; among them, internal tuning can use current or temperature or piezoelectric ceramics or laser arrays to continuously tune the light source; external tuning is when the multi-wavelength laser emits a fixed frequency. After lasing, a phase modulator, such as EOM, is used to tune the fixed-frequency laser. When the external tuning method is used, the RIN noise and linewidth characteristics of narrow linewidth lasers can be better controlled. For the combined narrow linewidth light source using external modulation, a single modulator can be used to achieve synchronous modulation of multiple wavelengths, which greatly reduces the number of modulation devices required. The multi-wavelength laser used for external tuning can use multiple narrow linewidth lasers to form an array, or can generate multiple wavelengths at a time by using the multi-longitudinal mode characteristics of a mode-locked laser. The multi-wavelength laser can also realize multi-wavelength output by means of EOM generating multi-sideband or multi-sideband tuning. The narrow linewidth laser can be a DFB, VCSEL, a monolithic non-planar ring cavity laser, or other solid, gas, semiconductor narrow linewidth tunable lasers, or a MOPA structure laser, and the like.

In the above step S3, firstly, the wave splitter is used to divide the signal of the detection light into different optical paths according to the wavelength; secondly, the processed signal of the detection light is output to the space through the laser transmitter, and the technology such as galvanometer or OPA is used to realize the transmission of the light. Scanning; when a space obstacle encounters the signal of the detection light, an echo signal will be generated.

In the above step S4, the echo signal is firstly received by the laser receiver and coupled into the optical path; secondly, the echo signal is returned to a single waveguide by the combiner; finally, the echo signal in the single waveguide is combined by the beam combiner Combined with the local oscillator light to form an interference signal.

In the above-mentioned step S5, the interference signal is sent to the photodetector according to the wavelength through the wave splitter; after the photodetector detects the interference signal, a multi-channel photoelectric signal is obtained. Among them, the photodetector adopts a photodetector array, and the devices used can be semiconductor (positive-intrinsic-negative, PIN), APD (avalanche photon diode), PDB (balanced photon detector), SPAD (single photon avalanchediode), etc.;

In the above-mentioned step S7, the data processor (DSP) controls the driving module and the wavelength tuning module of the laser according to the analysis result, and the calibration and correction module is used to detect the tuning characteristics of the multi-wavelength laser, and correct the influence of the nonlinearity of the tuning. On the one hand, the signal is fed back to the data processor (DSP) for demodulating the beat frequency signal detected by the photodetector PD (photo detector); on the other hand, it is used to adjust the driving and modulation signals of the laser; in the specific use process, The data processor can be a single-chip microcomputer, an FPGA, or a waveform generator. It is used to analyze the detected photoelectric signal into distance or speed information, analyze the nonlinear characteristics of the light source, and analyze the signal-to-noise ratio, etc.

The wavelength division multiplexing unit (WDM) in the embodiment of the present invention, that is, the above-mentioned wave splitter or multiplexer, adopts TFF, AWG, or WSS, or the like. Among them, TFF is a thin film filter, AWG is an arrayed waveguide grating, and WSS is a wavelength selective switch. These devices are used to realize beam splitting and beam combining of multiple wavelengths.

The wavelength division multiplexing laser radar integrated system provided by the present invention will be described in detail below through three embodiments.

Example 1:

Next, Embodiment 1 of the present invention will be described through three working modes.

The working mode 1 provided by the first embodiment of the present invention is specifically shown in FIG. 2 . The specific steps of the working mode 1 include:

S1. A narrow linewidth laser is used to output n (n≥1) narrow linewidth laser light sources with different central wavelengths to form a multi-wavelength light source array; each laser beam is modulated in m order by the photoelectric modulator EOM1, thereby generating m×n laser with wavelengths; then frequency tuning is generated by the electro-optical modulator EOM2, so as to obtain a tuned laser signal with m×n wavelengths;

S2. After the multi-wavelength tuned laser signal passes through the beam splitter, it is divided into local oscillator light and probe light;

S3. The local oscillator light enters the relevant optical path as the reference light; and the probe light passes through the demultiplexer (ie, the wavelength division multiplexing module in FIG. 2 ) to generate n×m laser beams, which are arranged in an array, and through the emission lens, the n×m laser beams are emitted; space obstacles (that is, the target in Figure 2) will generate echo signals after encountering the laser beams;

In this step, when n=m=1, there is no need to pass the demultiplexer; m=1 can be used as a special case without EOM;

S4. When receiving the echo signal reflected by the space obstacle, the laser receiver transmits the echo signal to the relevant optical path, and combines the echo signal and the local oscillator light into an interference signal.

S5. After the interference signal passes through the demultiplexer, the light of different center wavelengths is separated; the interference light of n×m different wavelengths is received by the photodetector "that is, the receiver array in Fig. 2";

S6. Perform frequency evaluation on the interference light of n×m different wavelengths by the data processor, and obtain n×m distances.

For the second working mode provided by Embodiment 1 of the present invention, refer to FIG. 3 for details. The specific steps of the second working mode include:

S1. Use a narrow linewidth laser to output n (n≥1) narrow linewidth laser light sources with different central wavelengths to form a narrow linewidth laser array; the narrow linewidth laser array is synthesized into a beam by a combiner, and the combined beam The laser generated by the photoelectric modulator EOM1 produces m-order tuning output, thereby generating a beam of n×m wavelengths;

S2. After the multi-wavelength tuned laser signal passes through the beam splitter, it is divided into local oscillator light and probe light;

S3. The local oscillator light enters the relevant optical path as the reference light; and the probe light passes through the demultiplexer (ie, the wavelength division multiplexing module in FIG. 3 ) to generate n×m laser beams, which are arranged in an array, and through the emission lens, the n×m laser beams are emitted; space obstacles (that is, the target in Figure 3) will generate echo signals after encountering the laser beams;

In this step, when n=m=1, there is no need to pass the demultiplexer; m=1 can be used as a special case without EOM;

S4. When receiving the echo signal reflected by the space obstacle, the laser receiver transmits the echo signal to the relevant optical path, and combines the echo signal and the local oscillator light into an interference signal.

S5. The interference signal is divided into different wavelengths after passing through the demultiplexer; n×m interference lights of different wavelengths are received through the receiver array;

S6. Perform frequency evaluation on the interference light of n×m different wavelengths by the data processor, and obtain n×m distances.

The third working mode provided by Embodiment 1 of the present invention is specifically shown in FIG. 4 . The specific steps of the third working mode include:

S1. Use a narrow linewidth laser to output n (n>=1) narrow linewidth laser light sources with different central wavelengths to form a narrow linewidth laser array; the narrow linewidth laser array is synthesized into a beam by a combiner, and the beam is combined. The latter laser passes through the photoelectric modulator EOM1 to generate m-order tuning output, thereby generating a beam of n × m wavelengths; the beam of n × m wavelengths passes through the laser amplifier Amplifier to obtain higher output power; here the amplifier can use EDFA ( Erbium-Doped Fiber Amplifier), SOA (Semiconductor Optical Amplifier), etc. The signal can be passed through a GFF (Gain Flattening Filter) to make the output power of each wavelength consistent.

S2. After the multi-wavelength tuned laser signal passes through the beam splitter, it is divided into local oscillator light and probe light;

S3. The local oscillator light enters the relevant optical path as the reference light; and the probe light passes through the demultiplexer (ie, the wavelength division multiplexing module in Fig. 4 ) to generate n×m laser beams, which are arranged in an array, and through the emission lens, the n×m laser beams are emitted; space obstacles (that is, the target in Figure 4) will generate echo signals after encountering the laser beams;

In this step, when n=1, there is no need to pass the demultiplexer;

S4. When receiving the echo signal reflected by the space obstacle, the laser receiver transmits the echo signal to the relevant optical path, and combines the echo signal and the local oscillator light into an interference signal.

S5. The interference signal is divided into different wavelengths after passing through the demultiplexer; n×m interference lights of different wavelengths are received through the receiver array;

S6. Perform frequency evaluation on the interference light of n×m different wavelengths by the data processor, and obtain n×m distances.

Embodiment 1 of the present invention proposes to use a group of multi-wavelength tuned light sources and a method of wavelength division multiplexing to realize solid-state one-dimensional illumination. Compared with the prior art, Embodiment 1 of the present invention realizes multi-wavelength tuning laser beams by combining multi-wavelength light sources, EOM multi-sideband generation and EOM tuning technologies; Line lidar can be implemented by combining 10 sets of laser light sources and EOM 10th-order sidebands (assuming that the number of EOM side-orders is 10). In addition, in Embodiment 1 of the present invention, the external tuning scheme can ensure that the laser has a narrow linewidth.

Embodiment 2, with reference to shown in Figure 5:

S1. A narrow linewidth laser is used to output n (n≥1) narrow linewidth laser light sources with different central wavelengths to form a tunable light source array; each light source is divided into m (m≥1) groups, and the The wavelength division multiplexing module (WDM) synthesizes m beams of light;

S2. After the multi-wavelength tuned laser signal passes through the beam splitter, it is divided into local oscillator light and probe light;

S3. The local oscillator light enters the relevant optical path as the reference light; and the probe light passes through the demultiplexer (ie, the wavelength division multiplexing module in FIG. 5 ) to generate n×m laser beams, which are arranged in an array, and through the emission lens, the n laser beams are emitted; space obstacles (that is, the target in Figure 5) will generate echo signals after encountering the laser beams;

S4. When receiving the echo signal reflected by the space obstacle, the laser receiver transmits the echo signal to m groups of related optical paths, and combines the echo signal and the local oscillator light into an interference signal.

S5. The interference signal is divided into different wavelengths after passing through the demultiplexer; n×m interference lights of different wavelengths are received through the receiver array;

S6. Perform frequency evaluation on the interference light of n×m different wavelengths by the data processor, and obtain n×m distances.

Compared with the single-channel ranging laser in Embodiment 1 of the present invention, a set of adjustable light sources and coherent optical paths are required. The multiplexing system, on the one hand, can expand the emission beam of the lidar, and on the other hand, it can reduce the problems of excessive insertion loss and low efficiency caused by too many wavelengths of a single wavelength division system. The invention can reduce the number of lasers by combining the beam splitter and the wave combiner. In this embodiment, only 10 groups of laser light sources and 10 groups of optical paths are needed to achieve 100-line laser radar ranging, which saves costs.

Embodiment 3, with reference to Figure 6:

S1. Use a narrow linewidth laser to output n (n≥1) narrow linewidth laser light sources with different central wavelengths to form a tuned laser array; the tuned laser array is synthesized into a beam by a combiner, and the combined laser is passed through the photoelectric The modulator EOM1 produces an m-order tuned output, resulting in a beam of n×m wavelengths;

S2. After the multi-wavelength tuned laser signal passes through the beam splitter, it is divided into local oscillator light and probe light;

S3. The local oscillator light enters the relevant optical path as the reference light; and the probe light passes through the demultiplexer (ie, the wavelength division multiplexing module in Fig. 6 ) to generate n×m laser beams, which are arranged in an array, and the emitting lens is used to generate n×m laser beams. n laser beams are emitted; space obstacles (that is, the target in Figure 6) will generate echo signals after encountering the laser beams;

In this step, when n=m=1, there is no need to pass the demultiplexer; m=1 can be used as a special case without EOM;

S4. When receiving the echo signal reflected by the space obstacle, the laser receiver transmits the echo signal to m groups of related optical paths, and combines the echo signal and the local oscillator light into an interference signal.

S5. The interference signal is divided into different wavelengths after passing through the demultiplexer; n×m interference lights of different wavelengths are received through the receiver array;

S6. Perform frequency evaluation on the interference light of n×m different wavelengths by the data processor, and obtain n×m distances.

Compared with the above-mentioned Embodiment 1 and Embodiment 2 of the present invention, Embodiment 3 of the present invention adopts an internally modulated laser array based on the wavelength division multiplexing radar. This method can reduce the number of devices in the system and make the system more compact. At the same time, the EOM external modulation technology can be used to expand the number of wavelengths. The original method of 100-line LiDAR requires 100 sets of lasers and coherent optical paths. In this embodiment, only 10 sets of laser light sources and optical paths can be used to achieve 100-line laser radar ranging, which saves costs.

In Figures 2 to 6 of the accompanying drawings, E _TX represents the transmitting electric field intensity; E _RX represents the receiving electric field intensity; E _LO represents the local oscillator electric field intensity.

The embodiment of the present invention also provides a wavelength division multiplexing laser radar integrated system, as shown in FIG. 7 , the system includes a multi-wavelength laser, a beam splitter, a laser transmitting subsystem, a laser receiving subsystem, a beam combiner, an optoelectronic A detector and a data processor; wherein, the multi-wavelength laser is used to output continuous multi-wavelength tuned laser light; the beam splitter is used to divide the multi-wavelength tuned laser light into local oscillator light and probe light; the laser emission subsystem is used to emit the probe light to Space; the laser receiving subsystem is used to receive the echo signal generated by the space obstacle; the beam combiner is used to combine the local oscillator light and the echo signal into an interference signal; the photodetector is used to detect the interference signal and obtain the photoelectric signal; The data processor is used to analyze the photoelectric signal, and obtain the distance and speed corresponding to the detection object of each wavelength according to the analysis result.

The above-mentioned multi-wavelength laser includes a driving module and a wavelength tuning module; the data processor is used to adjust the driving and modulation signals of the multi-wavelength laser by controlling the driving module and the wavelength tuning module.

The above-mentioned laser emission subsystem includes a wave splitter and a laser transmitter; wherein, the wave splitter is used for dividing the signal of the detection light into different optical paths according to the wavelength; the laser transmitter is used for outputting the signal of the detection light to the space.

The above-mentioned laser receiving subsystem includes a laser receiver and a wave combiner; wherein, the laser receiver is used for receiving echo signals; and the wave combiner is used for returning the echo signals into a single waveguide.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (10)

1. A method for wavelength division multiplexing lidar integration, comprising:

s1, outputting continuous multi-wavelength tuning laser by adopting a multi-wavelength laser;

s2, dividing the multi-wavelength tuned laser into local oscillation light and detection light after passing through a beam splitter;

s3, emitting the probe light to the space through a laser emission subsystem; generating an echo signal after the space obstacle meets the detection light;

s4, receiving the echo signal through a laser receiving subsystem, and combining the local oscillator light and the echo signal into an interference signal;

s5, detecting the interference signal through a photoelectric detector to obtain a photoelectric signal;

and S6, analyzing the photoelectric signal through a data processor, and obtaining the distance and the speed corresponding to the detection object of each wavelength according to the analysis result.

2. The wavelength division multiplexed lidar integration method of claim 1, further comprising:

and S7, the data processor corrects the beat frequency signal detected by the photoelectric detector according to the analysis result to obtain a more accurate beat frequency signal.

3. The wdm lidar integration method of claim 1, wherein the tuning of the multi-wavelength laser comprises an inner-tuning and an outer-tuning;

the internal regulation method comprises the following steps: continuously tuning the light source by current or temperature or piezoelectric ceramics;

the external adjustment method comprises the following steps: and after the multi-wavelength laser emits the fixed-frequency laser, tuning the fixed-frequency laser by adopting a phase modulator.

4. The wavelength division multiplexing lidar integration method of claim 1, wherein the S3 specifically comprises:

s31, dividing the signal of the detection light into different light paths according to wavelength by adopting a wave splitter;

s32, outputting the signal of the probe light processed by the S31 to a space through a laser transmitter;

and S33, generating an echo signal after the space obstacle meets the signal of the detection light.

5. The wavelength division multiplexing lidar integration method of claim 1, wherein the S4 specifically comprises:

s41, receiving the echo signal through a laser receiver;

s42, returning the echo signal into a waveguide through a combiner;

and S43, combining the echo signals in the waveguide and the local oscillator light into interference signals through a beam combiner.

6. The wavelength division multiplexing lidar integration method of claim 1, wherein the S5 specifically comprises:

s51, sending the interference signal to the photoelectric detector according to the wavelength through a wave splitter;

and S52, detecting the interference signal by the photoelectric detector to obtain a plurality of paths of photoelectric signals.

7. A wdm lidar integrated system configured to implement the method of any of claims 1-6, the system comprising: the system comprises a multi-wavelength laser, a beam splitter, a laser emission subsystem, a laser receiving subsystem, a beam combiner, a photoelectric detector and a data processor;

the multi-wavelength laser is used for outputting continuous multi-wavelength tuning laser;

the beam splitter is used for splitting the multi-wavelength tuning laser into local oscillation light and detection light;

the laser emission subsystem is used for emitting detection light to a space;

the laser receiving subsystem is used for receiving echo signals generated by space obstacles;

the beam combiner is used for combining the local oscillator light and the echo signal into an interference signal;

the photoelectric detector is used for detecting the interference signal to obtain a photoelectric signal;

and the data processor is used for analyzing the photoelectric signals and obtaining the distance and the speed corresponding to the detection object with each wavelength according to the analysis result.

8. The wdm integrated system of claim 7, wherein said data processor is further configured to modify the beat signal detected by said photodetector to obtain a more accurate beat signal.

9. The integrated WDM lidar system of claim 7, wherein the lasing subsystem comprises a demultiplexer and a lasing transmitter;

the wave splitter is used for splitting the signal of the detection light into different light paths according to the wavelength;

the laser transmitter is used for outputting a signal of the detection light to the space.

10. The wdm lidar integrated system of claim 7, wherein the laser receiver subsystem comprises a laser receiver and a combiner;

the laser receiver is used for receiving the echo signal;

the wave combiner is used for returning the echo signals into the waveguide.

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