WO2022099806A1 - 激光雷达系统 - Google Patents

激光雷达系统 Download PDF

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Publication number
WO2022099806A1
WO2022099806A1 PCT/CN2020/132324 CN2020132324W WO2022099806A1 WO 2022099806 A1 WO2022099806 A1 WO 2022099806A1 CN 2020132324 W CN2020132324 W CN 2020132324W WO 2022099806 A1 WO2022099806 A1 WO 2022099806A1
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Prior art keywords
local oscillator
laser
frequency
light
continuous wave
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PCT/CN2020/132324
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English (en)
French (fr)
Inventor
梁伟
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苏州镭智传感科技有限公司
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Publication of WO2022099806A1 publication Critical patent/WO2022099806A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/42—Simultaneous measurement of distance and other co-ordinates
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/50—Systems of measurement based on relative movement of target
    • G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems

Definitions

  • the present application relates to the field of laser technology, for example, to a laser radar system.
  • Frequency Modulated Continuous Wave (FMCW) system is an important type of radar; compared with traditional radar systems such as pulse radar and phase radar, it has high precision, anti-interference, no distance blind zone, direct speed measurement, structure Because of its simplicity and other advantages, it has good application prospects in many fields.
  • FMCW Frequency Modulated Continuous Wave
  • Frequency-modulated continuous wave lidar is based on laser interferometry, and the echoes scattered by the emitted light hitting the target need to interfere with the local oscillator light to detect an effective signal.
  • an interference system using free-space optical elements it is required that the angle of the echo and the angle of the local oscillator be strictly parallel to obtain a better interference signal.
  • a system using fiber coaxial transmission and reception requires the echo energy to be converged to the fiber.
  • an optical scanning mechanism needs to be used to scan the outgoing light in two-dimensional space. Due to the requirement of high frame rate, these scanning mechanisms usually have high angular velocity.
  • the optical axis of the scanning optical mechanism has been deflected, and an angular deviation occurs when the echoes interfere with the local oscillator light, resulting in a significant decrease in the spatial interference signal.
  • the scanning angular speed of the optical scanning mechanism is too fast, resulting in a significant reduction in the spatial coherent coupling loss of the coherent system echoes, and the farther the target is, the more likely it is. It is so.
  • the embodiment of the present application provides a lidar system, which can solve the problem of low spatial coupling efficiency of echo angle offset in the related art.
  • An embodiment of the present application provides a lidar system
  • the lidar system includes: a multi-wavelength output module, a branching and receiving module, a two-dimensional scanning mechanism, a first dispersion element disposed on the two-dimensional scanning mechanism, a second dispersion An element, a lens, a photodiode array, and a processing module; wherein the photodiode array includes a plurality of photodiodes.
  • the multi-wavelength output module is configured to output a frequency-modulated continuous wave laser, wherein the frequency-modulated continuous wave laser includes laser beams of different wavelengths.
  • the branching and receiving module is configured to divide the frequency-modulated continuous wave laser into local oscillator light and measurement light, and transmit the measurement light to the first dispersion element, and drive the two-dimensional scanning mechanism to drive the The first dispersive element performs spatial scanning; wherein, the first dispersive element radiates measurement light of different wavelengths in different directions, and combines the received target scattered echoes in different directions and transmits them to the branching and receiving module .
  • the branching and receiving module is further configured to transmit the local oscillator light and the target scattered echo to the second dispersion element; wherein the local oscillator light and the target scattered echo respectively comprise different wavelengths Element.
  • the second dispersion element is configured to reflect the local oscillator light and the target scattered echo; wherein, the local oscillator light and the target scattered echo with different wavelengths are reflected in different directions.
  • the lens is configured to condense the local oscillator light and the target scattered echoes to the photodiode array; wherein, a plurality of different photodiodes receive a plurality of local oscillator light and a plurality of different wavelengths in one-to-one correspondence.
  • the target scatters the echo, and the photodiode is placed in the focal plane of the lens.
  • the photodiode is configured to convert the local oscillator light and the target scattered echoes into electrical signals.
  • the processing module is configured to calculate the distance and speed of the target object according to different electrical signals converted by the photodiodes.
  • Figure 1 is a schematic structural diagram of a lidar system
  • FIG. 2 is a schematic structural diagram of a lidar system provided by an embodiment of the present application.
  • FIG. 3 is a curve for calculating the decrease of the interference coupling efficiency of two Gaussian beams of the same size as the included angle increases, provided by an embodiment
  • FIG. 4 is a schematic structural diagram of another lidar system provided by an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of another lidar system provided by an embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of a multi-wavelength output module provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of another multi-wavelength output module provided by an embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of another multi-wavelength output module provided by an embodiment of the present application.
  • FIG. 1 is a schematic structural diagram of a lidar system.
  • the FM continuous wave lidar includes a laser 10 ′, a beam splitter 20 ′, a circulator 30 ′, an angle scanning mechanism 40 ′, and a coupler 50 ', the photodiode 60' and the processor 70', the laser 10' is divided into the local oscillator light and the measurement light by the beam splitter 20'.
  • the measurement light exits through the circulator 30' and is spatially scanned by the angle scanning mechanism 40'.
  • the target scattered echo passes through the circulator 30', and interferes with another local oscillator light through the coupler 50'.
  • the interference signal is detected by the photodiode 60', and is sampled and calculated by the processor 70'.
  • the beam splitter 20 ′ may include, for example, a beam splitter 1
  • the circulator 30 ′ may include, for example, a polarization beam splitter 2 , a reflection mirror 3 and a polarization direction modulation unit 4 placed behind the polarization beam splitter 2 (the modulation unit 4 may be 1 /4 glass or 45 degree Faraday rotator)
  • the angle scanning mechanism 40 ′ may include a galvo scanning galvanometer, a MEMS galvanometer or a phased array, etc.
  • the coupler 50 ′ may include a beam combiner 5 .
  • the chirped laser output by the laser 10' is divided into local oscillator light and measurement light through the beam splitter 1, and the measurement light is transmitted to the angle scanning mechanism 40' through the polarizing beam splitter 2, and the angle scanning mechanism 40' performs spatial scanning.
  • the target scattered echo returns along the original path, as indicated by the dotted line, the direction of the target scattered echo adjusted by the reflector 3 is exactly the same as that of the local oscillator after passing through the beam combiner 5, so that the photodiode 60' can generate an effective output. interference signal.
  • the space scanning usually rotates at a high speed in the direction of a fast axis, when the long-distance echo returns, the space scanning has turned the preset angle, causing the target scattered echo to deviate from the optimum as shown by the dotted line.
  • the coherent electrical signal is greatly lost when it interferes with the local oscillator light.
  • FIG. 2 is a schematic structural diagram of a lidar system provided by an embodiment of the present application.
  • the lidar system provided by this embodiment includes a multi-wavelength output module 10 , a branching and receiving module 20 , and a two-dimensional scanning mechanism 41.
  • the output module 10 is configured to output a frequency-modulated continuous wave laser, wherein the frequency-modulated continuous wave laser includes laser beams of different wavelengths;
  • the branching and receiving module 20 is configured to divide the frequency-modulated continuous wave laser into a local oscillator light and a measurement light, and the measurement light It is transmitted to the first dispersive element 40, and the first dispersive element 40 is driven by the two-dimensional scanning mechanism 41 to perform spatial scanning; wherein, the first dispersive element 40 is set to emit the measurement light of different wavelengths in different directions, and to receive different The target scattered echo in the direction is transmitted to the branching and receiving module 20; the branching and receiving module 20 is further configured to transmit the local oscillator light and the target scattered echo to the second
  • the oscillating light and the target scattered echoes are converged into the photodiode array 70; wherein, a plurality of different photodiodes 71 receive the interference signals of the local oscillator light of a plurality of different wavelengths and the target scattered echoes in one-to-one correspondence, and the photodiodes 71 are set On the focal plane of the lens 60 ; the photodiode 71 is configured to convert the interference signal into an electrical signal; the processing module 80 is configured to calculate the distance and speed of the target object according to the electrical signals converted by different photodiodes 71 .
  • the first dispersive element 40 and the second dispersive element 50 may include gratings, prisms, and the like, respectively.
  • the two-dimensional scanning mechanism 41 may include a galvo scanning galvanometer, a MEMS galvanometer, a phased array, or the like.
  • the first dispersive element 40, the second dispersive element 50 and the two-dimensional scanning mechanism 41 include but are not limited to the above examples, and the types of the first dispersive element 40, the second dispersive element 50 and the two-dimensional scanning mechanism 41 can be selected according to the actual situation, as long as It can be achieved that the measurement light of different wavelengths can be directed to different directions.
  • the multi-wavelength output module 10 outputs a frequency-modulated continuous wave light source, wherein the output frequency-modulated continuous wave light source contains a plurality of wavelength components.
  • the branching and receiving module 20 divides the frequency-modulated continuous wave light source into a local oscillator light and a measuring light, wherein the local oscillator light and the measuring light both contain different wavelength components.
  • the branching and receiving module 20 transmits the measurement light containing different wavelength components to the first dispersion element 40, the measurement light of different wavelengths is directed to different directions through the first dispersion element 40, and the two-dimensional scanning mechanism 41 drives the first dispersion element 41.
  • the dispersive element 40 performs spatial scanning, so that the emitted light beam can cover the space of one direction dimension, for example, the direction of the fast axis corresponding to the first scattering element 40 in FIG. 2 .
  • the first dispersive element 40 only needs to scan the angle in the slow axis direction, and the scan frequency may be lower than 20 Hz, for example. Due to the slower scanning speed, a larger spot, such as a centimeter-scale spot, can be used without worrying about the mismatch of the target scattered echo angles.
  • the first scattering element 40 can emit light beams with different wavelengths at different angles, so that it is not necessary to scan a larger angle when scanning, avoiding the need for The problem of angular offset due to the deflection of the two-dimensional scanning mechanism 41 . Since the emission directions of the measurement light of each wavelength are different, when the measurement light reaches the target object, scattering occurs, and the target scattered echoes return to the first scattering element 40 from different directions and converge in the same direction. It is coupled with the local oscillator light through the branching and receiving module 20, and both the coupled local oscillator light and the target scattered echo contain components of different wavelengths.
  • the local oscillator light of different wavelengths and the target scattered echoes of different wavelengths are reflected to different directions through the second dispersive element 50, and then converged to the photodiode 71 through the lens 60, wherein different photodiodes 71 correspond to different wavelengths.
  • Local oscillator light and target scattered echoes are reflected to different directions through the second dispersive element 50, and then converged to the photodiode 71 through the lens 60, wherein different photodiodes 71 correspond to different wavelengths.
  • the photodiode array 70 includes four photodiodes 71 , and the four photodiodes 71 can be a first photodiode 711 , a second photodiode 712 , and a third photodiode 713 and the fourth photodiode 714,
  • the frequency-modulated continuous wave laser includes four wavelengths of laser beams, such as laser beams with wavelengths of ⁇ 1, ⁇ 2, ⁇ 3 and ⁇ 4;
  • the second dispersion element 50 combines the local oscillator light with a wavelength of ⁇ 1 and a wavelength of ⁇ 1
  • the target scattered echo is transmitted to the first photodiode 711 through the lens 60, the local oscillator light with a wavelength of ⁇ 2 and the target scattered echo with a wavelength of ⁇ 2 are transmitted to the second photodiode 712 through the lens 60, and the local oscillator with a wavelength of ⁇ 3 is transmitted.
  • the vibrating light and the target scattered echo with a wavelength of ⁇ 3 are transmitted to the third photodiode 713 through the lens 60, and the local oscillator light with a wavelength of ⁇ 4 and the target scattered echo with a wavelength of ⁇ 4 are transmitted to the fourth photodiode 714 through the lens 60,
  • the first photodiode 711, the second photodiode 712, the third photodiode 713, and the fourth photodiode 714 convert the interference signals of the local oscillator light and the target scattered echo into electrical signals, so that the processing module 80 can make the 71
  • the converted electrical signal calculates information such as the distance and speed of the target object. In this way, the parallel measurement of the original fast axis scanning space is realized.
  • Fig. 3 is a curve of calculating the decrease of the interference coupling efficiency of two Gaussian beams with the same size as the included angle increases.
  • the Gaussian beam radius in the optical path is 2.5 mm
  • the scanning angle of the fast axis of the galvanometer is 1rad
  • the scanning frequency is 250Hz
  • the one-way scanning time is 2ms
  • the angle changes by 0.5mrad.
  • the coupling efficiency is greatly reduced to Below 1% of the ideal value, the signal is lost by more than 20dB.
  • the scattered echo decays with the inverse square of the distance, and the long-distance echo is already very weak, and the 20dB interference loss due to the angle deviation is unacceptable.
  • the spot divergence angle is smaller, and the coherent coupling is more sensitive to angle changes.
  • the multi-wavelength laser and the wavelength division multiplexing method can be used to simultaneously measure distances in different directions in one dimension space at the same time, so that a fast large-scale angle scanning of a fast axis can be omitted or the scanning range can be reduced.
  • the frequency is low, for example, 20 Hz, and the time required for a half cycle of one-way scanning is 25 ms.
  • the frequency sweep rate is preferably at least 100MHz/us, and the sweep range can be selected to determine the single measurement time.
  • the first scattering element 40 is arranged in the two-dimensional scanning mechanism 41, the first scattering element 40 can Light beams with different wavelengths are emitted at different angles, so that when scanning, it is not necessary to scan a larger angle, which solves the problem of low spatial coupling efficiency of echo angle offset.
  • the distance can be measured in parallel in different directions in one dimension space at the same time.
  • the two dispersive elements and the photodiode interfere with signals of different wavelengths respectively.
  • a beam expander 30 is arranged between the first dispersive element 40 and the branching and receiving module 20, and the beam expander 30 expands the light spots of the measurement light of different wavelengths. More waves.
  • the lidar system further includes an amplifier 91, which is arranged between the multi-wavelength output module 10 and the branching and receiving module 20, and is arranged to amplify the energy of the frequency-modulated continuous wave laser to increase the frequency of each The energy of each wavelength component to achieve the purpose of distance measurement.
  • an amplifier 91 which is arranged between the multi-wavelength output module 10 and the branching and receiving module 20, and is arranged to amplify the energy of the frequency-modulated continuous wave laser to increase the frequency of each The energy of each wavelength component to achieve the purpose of distance measurement.
  • a transimpedance differential amplifier 90 is arranged between the photodiode array 70 and the processing module 80 , and the electrical signal (current) output by the photodiode 71 is converted into a voltage through the transimpedance differential amplifier 90 , so that the processing module 80 Calculate the distance and speed of the target object according to different voltages.
  • the specific structure of the branching and receiving module 20 may have a variety of different structures of the branching and receiving module 20, and the working principles of the branching and receiving modules 20 with various different structures are slightly different.
  • the working principle of the branching and receiving module 20 and the working principle of the lidar system will be described in detail below with reference to specific examples. The following content does not constitute a limitation to this application.
  • FIG. 4 is a schematic structural diagram of another lidar system provided by an embodiment of the present application.
  • the branching and receiving module 20 includes a beam splitter 21 , a circulator 22 and a coupler 23 .
  • the input end of the beam splitter 21 is connected with the output end of the multi-wavelength output module 10, and is arranged to receive the frequency-modulated continuous wave laser output of the multi-wavelength output module 10; the first output end of the beam splitter 21 is connected with the first output end of the circulator 22 The second output end of the beam splitter 21 is connected to the first input end of the coupler 23.
  • the beam splitter 21 is set to divide the frequency-modulated continuous wave laser into local oscillator light and measurement light, and pass through the beam splitter 21.
  • the second output end transmits the local oscillator light to the first input end of the coupler 23 ;
  • the second end of the circulator 22 is connected to the first dispersive element 40 , and the third end of the circulator 22 is connected to the second input end of the coupler 23 connected, the second end of the circulator 22 is set to transmit the measurement light to the first dispersion element 40, the second input end of the coupler 23 is set to receive the target scattered echo;
  • the output end of the coupler 23 is set to transmit the local oscillator light and the target scattered echoes are coupled to the second dispersive element 50 .
  • the beam splitter 21 divides the frequency-modulated continuous wave light source into local oscillator light and measurement light, wherein both the local oscillator light and the measurement light contain different wavelength components.
  • the second end of the circulator 22 transmits the measurement light of different wavelength components to the first dispersive element 40, and drives the first dispersive element 40 through the two-dimensional scanning mechanism 41 to emit the measurement light of different wavelengths in different directions, which can cover a In the space of direction dimension, the first dispersive element 40 only needs to scan the angle in the slow axis direction and scan the small angle in the fast axis direction.
  • the outgoing directions of the measurement light of each wavelength are different, when the measurement light reaches the target object, scattering occurs, and the target scattered echoes return to the first scattering element 40 from different directions and converge in the same direction. It is transmitted to the coupler 23 through the third end of the circulator 22, and the coupled local oscillator light and the target scattered echo both contain different wavelength components. Then, the local oscillator light of different wavelengths and the target scattered echoes of different wavelengths are reflected to different directions through the second dispersive element 50, and then converged to a photodiode 71 through the lens 60, wherein different photodiodes 71 correspond to different wavelengths. LO and target scattered echoes. The local oscillator light and the target scattered echoes are converted into electrical signals by the photodiodes 71 , so that the processing module 80 calculates information such as the distance and speed of the target object according to the electrical signals converted by each photodiode.
  • FIG. 5 is a schematic structural diagram of another lidar system provided by an embodiment of the present application.
  • the branching and receiving module 20 includes a partial reflection mirror 24 , a polarization beam splitter 25 and a polarization direction.
  • the adjustment unit 26; the partial reflection mirror 24 is arranged to divide the frequency-modulated continuous wave laser into the local oscillator light and the measurement light, and transmit the measurement light to the first dispersion element 40, and transmit the local oscillator light to the polarization direction adjustment unit 26; the polarization direction
  • the adjustment unit 26 is configured to change the polarization direction of the local oscillator light and the polarization direction of the target scattered echo, and transmit the local oscillator light and the target scattered echo after the polarization direction has been changed to the polarization beam splitter 25; the polarization beam splitter 25 is set to The local oscillator light and the target scattered echo are transmitted to the second dispersive element 50 .
  • the polarization direction adjusting unit 26 may be a Raday polarization rotator or a quarter glass or the like.
  • the polarization direction adjusting unit 26 includes but is not limited to the above examples, as long as the polarization direction of light can be changed, it is within the protection scope of the present application.
  • the frequency modulated continuous wave laser is transmitted to the partial reflection mirror 24 through the polarization beam splitter 25 and the polarization direction adjustment unit 26, and the partial beam is reflected by the partial reflection mirror 24, that is, the local oscillator;
  • both the local oscillator light and the measurement light contain different wavelength components.
  • the measurement light of different wavelength components is transmitted to the first dispersive element 40, and the first dispersive element 40 is driven by the two-dimensional scanning mechanism 41 to emit the measurement light of different wavelengths in different directions, which can cover the space of one direction dimension.
  • the dispersive element 40 only needs to scan an angle in the slow axis direction and a small angle scan in the fast axis direction.
  • the outgoing directions of the measurement light of each wavelength are different, when the measurement light reaches the target object, scattering occurs, and the target scattered echoes return to the first scattering element 40 from different directions and converge in the same direction.
  • the polarization direction adjusting unit 26 After passing through the partial reflecting mirror 24, it is transmitted to the polarization direction adjusting unit 26, and the polarization direction of the target scattered echo is changed by the polarization direction adjusting unit 26.
  • the polarization direction adjusting unit 26 is a 1/4 glass
  • the target scattered echo is the same as this one.
  • the vibrating light is polarized and rotated by 90 degrees through the 1/4 glass, and then reflected to the second dispersive element 50 through the polarizing beam splitter 25 .
  • the local oscillator light of different wavelengths and the target scattered echoes of different wavelengths are reflected to different directions through the second dispersive element 50, and then converged to a photodiode 71 through the lens 60, wherein different photodiodes 71 correspond to different wavelengths of the local oscillator. Vibration and target scattered echoes.
  • the local oscillator light and the target scattered echoes are converted into electrical signals by the photodiodes 71 , so that the processing module 80 calculates information such as the distance and speed of the target object according to the electrical signals converted by each photodiode.
  • the local oscillator light is formed by reflecting light from a partial reflection mirror 24 behind the polarization direction adjusting unit 26 .
  • the target scattered echo and the local oscillator light are polarized and rotated by 90 degrees through the polarization direction adjusting unit 26, and then reflected by the polarization beam splitter PBS, and the structure is simple.
  • the wavelength laser source may be generated by combining laser beams of different wavelengths, or a single laser may be generated by modulation or nonlinear effect optical frequency comb.
  • the method of generating laser beams of different wavelengths of the present application will be described in detail below with reference to examples, but the following examples do not constitute limitations of the present application, as long as laser beams of different wavelengths can be generated, they are all within the protection scope of the present application.
  • FIG. 6 is a schematic structural diagram of a multi-wavelength output module provided by an embodiment of the present application.
  • the multi-wavelength output module 10 includes a laser emitting unit 11 and a wavelength division beam combining unit 12;
  • the transmitting unit 11 is configured to emit a frequency-modulated continuous-wave laser, wherein the frequency-modulated continuous-wave laser includes laser beams of different wavelengths;
  • the wavelength-division beam combining unit 12 is configured to combine the frequency-modulated continuous wave laser to output to the branching and receiving module 20 .
  • a plurality of lasers with different wavelengths may be directly combined by the wavelength division beam combining unit 12, wherein the wavelength division beam combining unit 12 may be a wavelength division multiplexer (WDM, Wavelength Division Multiplexing) or an arrayed waveguide.
  • WDM wavelength division multiplexer
  • AWG Arrayed Waveguide Grating
  • FIG. 7 is a schematic structural diagram of another multi-wavelength output module provided by an embodiment of the present application.
  • the multi-wavelength output module 10 includes a laser emission unit 11 and a modulation unit 14; the laser emission unit 11 is configured to emit a laser beam of one wavelength; the modulation unit 14 is configured to modulate the laser beam of one wavelength to generate laser beams of different wavelengths.
  • the modulation unit 14 may include, for example, a single, or a combination of multiple phase or intensity modulators, or modulators placed in an optical cavity, so as to generate more wavelength components with uniform energy distribution.
  • the laser emitting unit 11 generates a single laser, which is then modulated by the modulation unit 14 to generate laser beams of different wavelengths.
  • a single laser is generated by the laser emitting unit 11, and only one laser source is frequency modulated, that is, only a single laser needs to be scanned linearly in frequency, and the frequency scanning is automatically applied to each wavelength component. In this way, all the Light of wavelength components can be synchronized with the same rate of frequency modulation.
  • FIG. 8 is a schematic structural diagram of another multi-wavelength output module provided by an embodiment of the present application.
  • the multi-wavelength output module 10 includes a laser emitting unit 11 and a nonlinear optical cavity 15 .
  • the laser emission unit 11 is configured to emit a laser beam of one wavelength
  • the nonlinear optical cavity 15 is configured to generate laser beams of different wavelengths according to the laser beam of one wavelength.
  • the nonlinear optical cavity 15 can be a high-quality annular cavity, and various wavelength components are directly generated through the nonlinear effect optical frequency comb, thereby realizing the laser beams of different wavelengths. output.
  • the laser emitting unit 11 also generates a single laser, and only needs to perform frequency modulation on one laser source, that is, only need to perform a linear frequency scan on the single laser, and the frequency scan is automatically loaded on each wavelength component. In this way, Light of all wavelength components can be synchronized at the same rate of frequency modulation.

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Abstract

一种调频连续波激光雷达，包括多波长输出模块（10）、分路和接收模块（20）、二维扫描机构（41）、设置于二维扫描机构（41）上的第一色散元件（40）、第二色散元件（50）、透镜（60）、光电二极管阵列（70）和处理模块（80）；多波长输出模块（10）设置为输出调频连续波激光，其中，调频连续波激光包括不同波长的激光光束，分路和接收模块（20）设置为将调频连续波激光分为本振光和测量光，且将测量光传输至第一色散元件（40），第一色散元件（40）设置为将不同波长的测量光射向不同的方向，并将接收的不同方向的目标散射回波传输至分路和接收模块（20）；分路和接收模块（20）还设置为将本振光和目标散射回波传输至第二色散元件（50），第二色散元件（50）设置为将本振光和目标散射回波进行反射，不同波长的本振光和目标散射回波反射的方向不同，光电二极管阵列（70）包括多个光电二极管（71），不同光电二极管（71）对应不同的波长的本振光和目标散射回波。

Description

激光雷达系统
本申请要求申请日为2020年11月10日、申请号为202011247071.3的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本申请涉及激光技术领域，例如涉及一种激光雷达系统。
背景技术
调频连续波(Frequency Modulated Continuous Wave，FMCW)体制是一种重要的雷达类型；相比于脉冲雷达、相位雷达等传统雷达体制而言具有精度高、抗干扰、无距离盲区、能直接测速、结构简单等优势，因而在很多领域具有良好的应用前景。
调频连续波激光雷达基于激光干涉测量，发射出去的光打到目标上散射的回波与本振光需要干涉才能探测到有效的信号。对于使用自由空间光学元件的干涉系统，要求回波的角度与本振光角度严格的平行，才能得到较好的干涉信号。例如，使用光纤同轴收发的系统，则要求回波能汇聚到光纤。对于成像激光雷达，需要使用光学扫描机构，对出射光进行二维空间扫描，由于高帧率的要求，通常这些扫描机构角速度很高。而对于远距离回波，例如150米外回波延时1μs，则扫描光学机构的光轴已经发生了偏转，回波与本振光干涉时产生了角度偏差，造成空间干涉信号显著下降。尤其对于应设置为自动驾驶机器人等的成像激光雷达，由于追求高分辨率和帧率，光学扫描机构扫描角速度过快，造成相干系统回波空间相干耦合损耗大为降低，对越远的目标越是如此。
发明内容
本申请实施例申请提供了一种激光雷达系统，能够解决相关技术中回波角度偏移空间耦合效率低的问题。
本申请实施例提供了激光雷达系统，该激光雷达系统包括：多波长输出模块、分路和接收模块、二维扫描机构、设置于所述二维扫描机构上的第一色散元件、第二色散元件、透镜、光电二极管阵列和处理模块；其中，所述光电二极管阵列包括多个光电二极管。
所述多波长输出模块设置为输出调频连续波激光，其中，所述调频连续波 激光包括不同波长的激光光束。
所述分路和接收模块设置为将所述调频连续波激光分为本振光和测量光，且将所述测量光传输至所述第一色散元件，通过所述二维扫描机构带动所述第一色散元件做空间扫描；其中，所述第一色散元件将不同波长的测量光射向不同的方向，并将接收的不同方向的目标散射回波汇合后传输至所述分路和接收模块。
所述分路和接收模块还设置为将所述本振光和所述目标散射回波传输至所述第二色散元件；其中，所述本振光和所述目标散射回波分别包括不同波长成分。
所述第二色散元件设置为将所述本振光和所述目标散射回波进行反射；其中，不同波长的本振光和目标散射回波反射的方向不同。
所述透镜设置为将所述本振光和所述目标散射回波汇聚到所述光电二极管阵列；其中，多个不同的所述光电二极管一一对应的接收多个不同波长的本振光和目标散射回波，且所述光电二极管设置在所述透镜的焦平面上。
所述光电二极管设置为将所述本振光和所述目标散射回波转换为电信号。
所述处理模块设置为根据不同所述光电二极管转换的电信号计算目标物体的距离和速度。
附图说明
图1是一种激光雷达系统的结构示意图；
图2是本申请一实施例提供的一种激光雷达系统的结构示意图；
图3是一实施例提供的计算两个同样大小的高斯光束干涉耦合效率随夹角增加而下降的曲线；
图4是本申请一实施例提供的又一种激光雷达系统的结构示意图；
图5是本申请一实施例提供的又一种激光雷达系统的结构示意图；
图6是本申请一实施例提供的一种多波长输出模块的结构示意图；
图7是本申请一实施例提供的又一种多波长输出模块的结构示意图；
图8是本申请一实施例提供的又一种多波长输出模块的结构示意图。
具体实施方式
图1是为一种激光雷达系统的结构示意图，如图1所示，该调频连续波激光 雷达包括激光器10’、分束器20’、环形器30’、角度扫描机构40’、耦合器50’、光电二极管60’和处理器70’，激光器10’通过分束器20’分为本振光和测量光。测量光通过环形器30’出射由角度扫描机构40’做空间扫描。目标散射回波经过环形器30’，与另一路本振光通过耦合器50’合束干涉，干涉信号由光电二极管60’检测，并由处理器70’采样计算。其中，分束器20’例如可以包括分光片1，环形器30’例如可以包括偏振分光镜2、反射镜3以及置于偏振分光镜2后的偏振方向调制单元4(调制单元4可以为1/4玻片或45度法拉第旋转片)，在一实施例中，角度扫描机构40’可以包括galvo扫描振镜、MEMS振镜或相控阵等，耦合器50’可以包括合束片5。在一实施例中，激光器10’输出的线性调频激光经过分光片1分为本振光和测量光，测量光通过偏振分光镜2传输至角度扫描机构40’，角度扫描机构40’做空间扫描。目标散射回波正常情况下沿原路返回，如虚线表示，目标散射回波通过反射镜3调节方向与本振光经过合束片5后具有完全一致的方向，才能在光电二极管60’产生有效的干涉信号。但实际使用中，由于做空间扫描通常在一个快轴方向做高速旋转，远距离回波返回时，做空间扫描已经转过了预设角度，造成目标散射回波如虚线所示偏离了最佳的干涉光方向，在与本振光干涉时相干电信号受到很大损失。
基于上述技术问题，本实施例提供了一种激光雷达系统，本实施例提供的激光雷达系统。图2是本申请实施例提供的一种激光雷达系统的结构示意图，如图2所示，本实施例提供的激光雷达系统包括多波长输出模块10、分路和接收模块20、二维扫描机构41、设置于二维扫描机构41上的第一色散元件40、第二色散元件50、透镜60、光电二极管阵列70和处理模块80；其中，光电二极管阵列70包括多个光电二极管71；多波长输出模块10设置为输出调频连续波激光，其中，调频连续波激光包括不同波长的激光光束；分路和接收模块20设置为将调频连续波激光分为本振光和测量光，且将测量光传输至第一色散元件40，通过二维扫描机构41带动第一色散元件40做空间扫描；其中，第一色散元件40设置为将不同波长的测量光射向不同的方向，并将接收的不同方向的目标散射回波传输至分路和接收模块20；分路和接收模块20还设置为将本振光和目标散射回波传输至第二色散元件50；其中，本振光和目标散射回波分别包括不同波长成分；第二色散元件50设置为将本振光和目标散射回波进行反射；其中，不同波长的本振光和目标散射回波反射的方向不同；透镜60设置为将本振光和目标散射回波汇聚到光电二极管阵列70；其中，多个不同的光电二极管71一一对应的 接收多个不同波长的本振光和目标散射回波的干涉信号，且光电二极管71设置在透镜60的焦平面上；光电二极管71设置为将干涉信号转换为电信号；处理模块80设置为根据不同光电二极管71转换的电信号计算目标物体的距离和速度。
在一实施例中，第一色散元件40和第二色散元件50可以分别包括光栅、棱镜等。二维扫描机构41可以包括galvo扫描振镜、MEMS振镜或相控阵等。第一色散元件40、第二色散元件50和二维扫描机构41包括但不限于上述示例，可以根据实际情况选择第一色散元件40、第二色散元件50和二维扫描机构41的类型，只要可以实现将不同波长的测量光射向不同的方向即可。
在一实施例中，多波长输出模块10输出调频连续波光源，其中，输出的调频连续波光源含有多个波长组分。分路和接收模块20将此调频连续波光源分为本振光和测量光，其中，本振光和测量光均含有不同波长成分。分路和接收模块20将含有不同波长成分的测量光传输至第一色散元件40，不同波长的测量光通过此第一色散元件40射向不同的方向，且通过二维扫描机构41带动第一色散元件40做空间扫描，如此使得射出的光束可以覆盖一个方向维度的空间，例如图2中的第一散射元件40对应的快轴方向。如此，第一色散元件40只需要在慢轴方向扫描角度，扫描频率例如可以低于20Hz。由于扫描速度较慢，可以使用较大的光斑，例如厘米尺度的光斑，而无需担心目标散射回波角度不匹配的问题。且由于第一散射元件40设置于二维扫描机构41，第一散射元件40就可以将不同波长的光束以不同的角度射出去，如此，扫描的时候就不需要扫描更大的角度，避免了由于二维扫描机构41偏转造成的角度偏移的问题。由于各波长的测量光的出射的方向不同，所以当测量光达到目标物体后发生散射，且目标散射回波从不同方向返回第一散射元件40，沿同一个方向汇合。经过分路和接收模块20与本振光耦合，耦合的本振光和目标散射回波均含有不同波长成分。再通过第二色散元件50将不同波长的本振光和不同波长的目标散射回波反射至不同的方向，然后通过透镜60汇聚于至光电二极管71，其中，不同光电二极管71对应不同的波长的本振光和目标散射回波，在一实施例中，光电二极管阵列70包括四个光电二极管71，四个光电二极管71可以为第一光电二极管711、第二光电二极管712、第三光电二极管713和第四光电二极管714，调频连续波激光包括四个波长的激光光束，例如波长为λ1、λ2、λ3和λ4的激光光束；第二色散元件50将波长为λ1的本振光和波长为λ1的目标散射回波通过透镜60传输至第一光电二极管711，将波长为λ2的本振光和波长为λ2的目标散射回波通过透镜60传输 至第二光电二极管712，将波长为λ3的本振光和波长为λ3的目标散射回波通过透镜60传输至第三光电二极管713，将波长为λ4的本振光和波长为λ4的目标散射回波通过透镜60传输至第四光电二极管714，第一光电二极管711、第二光电二极管712、第三光电二极管713和第四光电二极管714将本振光和目标散射回波的干涉信号转换为电信号，以使处理模块80根据每个光电二极管71转换的电信号计算目标物体的距离和速度等信息。如此，实现对原快轴扫描空间的并行测量。
参见图3，其中，图3是计算两个同样大小的高斯光束干涉耦合效率随夹角增加而下降的曲线。在一实施例中，假设光路中高斯光束半径为2.5mm，1550nm光衍射发散角半角为θ＝0.2mrad。振镜快轴扫描角度1rad，扫描频率为250Hz，单向扫描时间为2ms，角速度平均1rad/2ms＝500rad/s，对于150米目标往返1us，角度变化0.5mrad，根据图3耦合效率大大降低到低于理想值的1％以下，损失超过20dB信号。散射回波随距离平方反比衰减，远距离回波已经很弱，由于角度偏差干涉损失20dB是无法接受的。如果要提高光斑大小以增加回波接收面积，例如半径为5mm的光斑，光斑发散角更小，相干耦合对角度变化更为敏感。同时快轴250Hz，慢轴如果要达到10Hz，则慢轴方向分辨率仅为250/10＝25，要提高分辨率，快轴频率还需要进一步提高，角度扫描更快，回波角度不匹配的问题更加严重。所以本实施例通过多波长激光和波分复用方法，可同时对一个维度空间不同方向并行同时测距，如此可省去一个快轴的快速大范围角度扫描或降低扫描范围，由于慢轴扫描频率低，例如为20Hz，单向扫描半个周期所需时间为25ms。而为了达到多普勒测速目的，扫频速率优选至少100MHz/us，可选择扫描范围来决定单次测量时间。例如1GHz扫描范围作三角波扫频，则单次测量时间为20us,慢轴角度像素可达25ms/20us＝1250，可获得较高的角度分辨率。或者以100us为一个像素点，可以完成5次测量，通过对数据取平均的方法，可以提高信噪比；且第一散射元件40设置于二维扫描机构41，第一散射元件40就可以将不同波长的光束以不同的角度射出去，如此，扫描的时候就不需要扫描更大的角度，解决回波角度偏移空间耦合效率低的问题。
本实施例的技术方案，通过采用多波长的激光光束，且通过第一色散元件将不同波长的光束反射至不同方向，可同时对一个维度空间不同方向并行同时测距，同时接收端通过设置第二色散元件和光电二极管对不同波长信号分别干涉，如此，可省去一个快轴的快速大角度扫描，解决回波角度偏移空间耦合效 率低的问题；此外，由于第一色散元件设置于二维扫描机构，如此，可以减小扫描的角度和范围，避免了由于二维扫描机构偏转造成的角度偏移的问题；此外，本实施例接收端通过第二色散元件和透镜的结合，可以采用较大光斑，接收的效率可以更高；且使得激光雷达系统的结构更加紧凑，体积更小，避免了采用光纤导致体积大的问题。
在一实施例中，在第一色散元件40和分路和接收模块20之间设置扩束器30，通过扩束器30将不同波长的测量光的光斑进行扩大，如此，接收的目标散射回波较多。
在一实施例中，激光雷达系统还包括放大器91，该放大器91设置在多波长输出模块10和分路和接收模块20之间，并设置为将调频连续波激光的能量进行放大，以增加每个波长组分的能量，达到测远距的目的。
在一实施例中，光电二极管阵列70和处理模块80之间设置跨阻差分放大器90，通过跨阻差分放大器90将光电二极管71的输出的电信号(电流)转换为电压，以使处理模块80根据不同的电压计算目标物体的距离和速度等信息。
在实际设置时，分路和接收模块20的具体结构可以有多种不同结构的分路和接收模块20，多种不同结构的分路和接收模块20工作原理略有不同。下面将结合具体示例对分路和接收模块20的工作原理以及激光雷达系统的工作原理进行详细说明。下述内容不构成对本申请的限定。
在一实施例中，图4是本申请实施例提供的又一种激光雷达系统的结构示意图，如图4所示，分路和接收模块20包括分束器21、环形器22和耦合器23；分束器21的输入端与多波长输出模块10的输出端连接，设置为接收多波长输出模块10输出的调频连续波激光；分束器21的第一输出端与环形器22的第一端连接，分束器21的第二输出端与耦合器23的第一输入端连接，分束器21设置为将调频连续波激光分为本振光和测量光，并通过分束器21的第二输出端将本振光传输至耦合器23的第一输入端；环形器22的第二端与第一色散元件40连接，环形器22的第三端与耦合器23的第二输入端连接，环形器22的第二端设置为将测量光传输至第一色散元件40，耦合器23的第二输入端设置为接收目标散射回波；耦合器23的输出端设置为将本振光和目标散射回波耦合至第二色散元件50。
在一实施例中，分束器21将此调频连续波光源分为本振光和测量光，其中，本振光和测量光均含有不同波长成分。通过环形器22的第二端将不同波长成分的测量光传输至第一色散元件40，通过二维扫描机构41带动第一色散元件40将 不同波长的测量光射向不同的方向，可以覆盖一个方向维度的空间，如此，第一色散元件40只需要在慢轴方向扫描角度和在快轴方向做小角度扫描。由于各波长的测量光的出射的方向不同，所以当测量光到达目标物体后发生散射，且目标散射回波从不同方向返回第一散射元件40，沿同一个方向汇合。经过环形器22的第三端传输至耦合器23，耦合的本振光和目标散射回波均含有不同波长成分。再通过第二色散元件50将不同波长的本振光和不同波长的目标散射回波反射至不同的方向，然后通过透镜60汇聚于一个光电二极管71，其中，不同光电二极管71对应不同的波长的本振光和目标散射回波。通过光电二极管71将本振光和目标散射回波转换为电信号，以使处理模块80根据每个光电二极管转换的电信号计算目标物体的距离和速度等信息。
在一实施例中，图5是本申请实施例提供的又一种激光雷达系统的结构示意图，如图5所示，分路和接收模块20包括部分反射镜24、偏振分光镜25和偏振方向调节单元26；部分反射镜24设置为将调频连续波激光分为本振光和测量光，并将测量光传输至第一色散元件40，将本振光传输至偏振方向调节单元26；偏振方向调节单元26设置为改变本振光的偏振方向和目标散射回波的偏振方向，并将偏振方向改变后的本振光和目标散射回波传输至偏振分光镜25；偏振分光镜25设置为将本振光和目标散射回波传输至第二色散元件50。
其中，偏振方向调节单元26可以为拉第偏振旋转片或1/4玻片等。偏振方向调节单元26包括但不限于上述示例，只要可以改变光的偏振方向都在本申请的保护范围内。
在一实施例中，调频连续波激光通过偏振分光镜25和偏振方向调节单元26传输至部分反射镜24，通过部分反射镜24将部分光束反射，即为本振光；同时部分光束通过，即为测量光束，其中，本振光和测量光均含有不同波长成分。不同波长成分的测量光传输至第一色散元件40，通过二维扫描机构41带动第一色散元件40将不同波长的测量光射向不同的方向，可以覆盖一个方向维度的空间，如此，第一色散元件40只需要在慢轴方向扫描角度和在快轴方向做小角度扫描。由于每个波长的测量光的出射的方向不同，所以当测量光达到目标物体后发生散射，且目标散射回波从不同方向返回第一散射元件40，沿同一个方向汇合。经过部分反射镜24后传输至偏振方向调节单元26，通过偏振方向调节单元26改变目标散射回波的偏振方向，例如当偏振方向调节单元26为1/4玻片时，目标散射回波与本振光通过1/4玻片偏振旋转90度，再通过偏振分光镜25反射至 第二色散元件50。通过第二色散元件50将不同波长的本振光和不同波长的目标散射回波反射至不同的方向，然后通过透镜60汇聚于一个光电二极管71，其中，不同光电二极管71对应不同的波长的本振光和目标散射回波。通过光电二极管71将本振光和目标散射回波转换为电信号，以使处理模块80根据每个光电二极管转换的电信号计算目标物体的距离和速度等信息。本实施例通过本振光由偏振方向调节单元26后的一个部分反射镜24反射光构成。目标散射回波与本振光通过偏振方向调节单元26偏振旋转90度，再通过偏振分光镜PBS反射，结构简单。
在一实施例中，产生不同波长的激光光束的方式也有多种，例如波长激光源可以是不同波长激光合束产生，也可以是单个激光通过调制或非线性效应光频梳产生。下面将结合示例对本申请的产生不同波长的激光光束的方式进行详细说明，但是下述示例不构成对本申请的限定，只要可以产生不同波长的激光光束，都在本申请的保护范围内。
在一实施例中，图6是本申请实施例提供的一种多波长输出模块的结构示意图，如图6所示，多波长输出模块10包括激光发射单元11和波分合束单元12；激光发射单元11设置为发射调频连续波激光，其中，调频连续波激光包括不同波长的激光光束；波分合束单元12设置为将调频连续波激光进行合束，以输出至分路和接收模块20。
在一实施例中，可以是多个不同波长的激光器通过波分合束单元12直接合束，其中，波分合束单元12可以为波分复用器(WDM，Wavelength Division Multiplexing)或阵列波导光栅(AWG，Arrayed Waveguide Grating)，每个激光器需以固定已知的频率扫描速率扫频。
在一实施例中，图7是本申请实施例提供的又一种多波长输出模块的结构示意图，如图7所示，多波长输出模块10包括激光发射单元11和调制单元14；激光发射单元11设置为发射一种波长的激光光束；调制单元14设置为对一种波长的激光光束进行调制，以产生不同波长的激光光束。
其中，调制单元14例如可以包括单个、或者多个相位或强度调制器的组合、或者置于光腔内的调制器，以产生较多的，能量分布均匀的波长组分。激光发射单元11产生单个激光，然后通过调制单元14对此单个激光进行调制，以产生不同波长的激光光束。本实施例中，通过激光发射单元11产生单个激光，只用对一个激光源做频率调制，即只需对单激光做频率线性扫描，该频率扫描自动加载于每个波长组分，如此，所有波长组分的光可以得到同步的同样速率的频 率调制。
在一实施例中，图8是本申请实施例提供的又一种多波长输出模块的结构示意图，如图8所示，所述多波长输出模块10包括激光发射单元11和非线性光腔15；激光发射单元11设置为发射一种波长的激光光束；非线性光腔15设置为根据一种波长的激光光束产生不同波长的激光光束。
本实施例中，通过将激光注入非线性光腔15，非线性光腔15可以为高品质环形腔，通过非线性效应光频梳直接产生多种波长组分，实现了不同波长的激光光束的输出。本实施例中，同样是激光发射单元11产生单个激光，只用对一个激光源做频率调制，即只需对单激光做频率线性扫描，该频率扫描自动加载于每个波长组分，如此，所有波长组分的光可以得到同步的同样速率的频率调制。

Claims (10)

  1. 一种激光雷达系统，包括：多波长输出模块、分路和接收模块、二维扫描机构、设置于所述二维扫描机构上的第一色散元件、第二色散元件、透镜、光电二极管阵列和处理模块；其中，所述光电二极管阵列包括多个光电二极管；
    所述多波长输出模块设置为输出调频连续波激光，其中，所述调频连续波激光包括不同波长的激光光束；
    所述分路和接收模块设置为将所述调频连续波激光分为本振光和测量光，且将所述测量光传输至所述第一色散元件，通过所述二维扫描机构带动所述第一色散元件做空间扫描；其中，所述第一色散元件将不同波长的测量光射向不同的方向，并将接收的不同方向的目标散射回波汇合后传输至所述分路和接收模块；
    所述分路和接收模块还设置为将所述本振光和所述目标散射回波传输至所述第二色散元件；其中，所述本振光和所述目标散射回波分别包括不同波长成分；
    所述第二色散元件设置为将所述本振光和所述目标散射回波进行反射；其中，不同波长的本振光和目标散射回波反射的方向不同；
    所述透镜设置为将所述本振光和所述目标散射回波汇聚到所述光电二极管阵列；其中，多个不同的所述光电二极管一一对应的接收多个不同波长的本振光和目标散射回波，且所述光电二极管设置在所述透镜的焦平面上；
    所述光电二极管设置为将所述本振光和所述目标散射回波转换为电信号；
    所述处理模块设置为根据不同所述光电二极管转换的电信号计算目标物体的距离和速度。
  2. 根据权利要求1所述的激光雷达系统，其中，所述分路和接收模块包括分束器、环形器和耦合器；
    所述分束器的输入端与所述多波长输出模块的输出端连接，并设置为接收所述多波长输出模块输出的所述调频连续波激光；
    所述分束器的第一输出端与所述环形器的第一端连接，所述分束器的第二输出端与所述耦合器的第一输入端连接，所述分束器设置为将所述调频连续波激光分为本振光和测量光，并通过所述第二输出端将所述本振光传输至所述耦合器的第一输入端；
    所述环形器的第二端与所述第一色散元件连接，所述环形器的第三端与所述耦合器的第二输入端连接，所述环形器的第二端设置为将所述测量光传输至 所述第一色散元件，所述耦合器的第二输入端设置为接收所述目标散射回波；
    所述耦合器的输出端设置为将所述本振光和所述目标散射回波耦合至所述第二色散元件。
  3. 根据权利要求1所述的激光雷达系统，其中，所述分路和接收模块包括部分反射镜、偏振分光镜和偏振方向调节单元；
    所述部分反射镜设置为将所述调频连续波激光分为本振光和测量光，并将所述测量光传输至所述第一色散元件，将所述本振光传输至所述偏振方向调节单元；
    所述偏振方向调节单元设置为改变所述本振光的偏振方向和所述目标散射回波的偏振方向，并将偏振方向改变后的本振光和目标散射回波传输至所述偏振分光镜；
    所述偏振分光镜设置为将所述本振光和所述目标散射回波传输至所述第二色散元件。
  4. 根据权利要求1所述的激光雷达系统，其中，所述多波长输出模块包括激光发射单元和波分合束单元；
    所述激光发射单元设置为发射调频连续波激光，其中，所述调频连续波激光包括不同波长的激光光束；
    所述波分合束单元设置为将所述调频连续波激光进行合束，以输出至所述分路和接收模块。
  5. 根据权利要求1所述的激光雷达系统，其中，所述多波长输出模块包括激光发射单元和调制单元；
    所述激光发射单元设置为发射调频连续波激光，其中，所述调频连续波激光包括一种波长的激光光束；
    所述调制单元设置为对所述调频连续波激光进行调制，以产生不同波长的激光光束。
  6. 根据权利要求5所述的激光雷达系统，其中，所述调制单元包括至少一个相位调制器或至少一个强度调制器。
  7. 根据权利要求1所述的激光雷达系统，其中，所述多波长输出模块包括激光发射单元和非线性光腔；
    所述激光发射单元设置为发射调频连续波激光，其中，所述调频连续波激光包括一种波长的激光光束；
    所述非线性光腔设置为根据所述调频连续波激光产生不同波长的激光光束。
  8. 根据权利要求1所述的激光雷达系统，还包括扩束器，设置在所述第一色散元件和所述分路和接收模块之间，设置为将所述不同波长的测量光的光斑进行扩大。
  9. 根据权利要求1所述的激光雷达系统，还包括放大器，设置在所述多波长输出模块和所述分路和接收模块之间，设置为将所述调频连续波激光的能量进行放大。
  10. 根据权利要求1所述的激光雷达系统，其中，所述第一色散元件和所述第二色散元件分别包括光栅或棱镜。
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CN116931002B (zh) * 2023-09-07 2023-12-29 深圳市速腾聚创科技有限公司 激光雷达及可移动设备
CN116908812A (zh) * 2023-09-14 2023-10-20 苏州旭创科技有限公司 半固态激光雷达系统
CN116908812B (zh) * 2023-09-14 2023-12-22 苏州旭创科技有限公司 半固态激光雷达系统
CN116930995A (zh) * 2023-09-19 2023-10-24 天津大学四川创新研究院 调频连续波激光高速目标的速度和距离测量系统及方法
CN116930995B (zh) * 2023-09-19 2023-11-28 天津大学四川创新研究院 调频连续波激光高速目标的速度和距离测量系统及方法

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