WO2021051696A1 - Fmcw lidar system - Google Patents

Fmcw lidar system Download PDF

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Publication number
WO2021051696A1
WO2021051696A1 PCT/CN2019/127767 CN2019127767W WO2021051696A1 WO 2021051696 A1 WO2021051696 A1 WO 2021051696A1 CN 2019127767 W CN2019127767 W CN 2019127767W WO 2021051696 A1 WO2021051696 A1 WO 2021051696A1
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WIPO (PCT)
Prior art keywords
port
signal
optical fiber
coupler
module
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PCT/CN2019/127767
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French (fr)
Chinese (zh)
Inventor
王超
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深圳市速腾聚创科技有限公司
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Priority to PCT/CN2019/127767 priority Critical patent/WO2021051696A1/en
Priority to CN201980051040.XA priority patent/CN113383246B/en
Publication of WO2021051696A1 publication Critical patent/WO2021051696A1/en

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S17/00Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06Systems determining position data of a target
    • G01S17/08Systems determining position data of a target for measuring distance only
    • G01S17/32Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S17/00Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/50Systems of measurement based on relative movement of target
    • G01S17/58Velocity or trajectory determination systems; Sense-of-movement determination systems
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481Constructional features, e.g. arrangements of optical elements
    • G01S7/4811Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
    • G01S7/4812Constructional features, e.g. arrangements of optical elements common to transmitter and receiver transmitted and received beams following a coaxial path
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481Constructional features, e.g. arrangements of optical elements
    • G01S7/4817Constructional features, e.g. arrangements of optical elements relating to scanning
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481Constructional features, e.g. arrangements of optical elements
    • G01S7/4818Constructional features, e.g. arrangements of optical elements using optical fibres
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO 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
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/491Details of non-pulse systems
    • G01S7/493Extracting wanted echo signals

Definitions

  • This application relates to the field of laser detection technology, and in particular to an FMCW lidar system.
  • Lidar is a radar system that emits laser beams to detect the target's position, speed and other characteristic quantities. Its working principle is to transmit a detection signal to the target, and then compare the received signal reflected from the target with the transmitted signal. After proper processing, relevant information of the target can be obtained, such as target distance, azimuth, height, speed, Attitude, even shape and other parameters, so as to detect, track and identify aircraft, missiles and other targets.
  • the principle of ranging is to emit a continuous wave with a linear change in frequency as the outgoing signal in the sweep period, a part of the outgoing signal is used as the local oscillator signal, and the rest is emitted outward for detection, and the return return after being reflected by the object There is a certain frequency difference between the wave signal and the local oscillator signal, and the distance information between the detected target and the radar can be obtained by measuring the frequency difference.
  • the FMCW lidar system it is often necessary to use a circulator to complete the emission of the outgoing signal and the reception of the echo signal.
  • the circulator often has insertion loss and strong echo interference, which leads to the low or even real signal-to-noise ratio of the system.
  • the intermediate frequency signal is completely annihilated and cannot be demodulated, resulting in the inability to accurately measure the position information of the target object.
  • the embodiment of the present application provides an FMCW lidar system, which can smoothly demodulate the intermediate frequency signal generated by interference, and then can accurately measure the position information of the target object.
  • the technical solution is as follows:
  • the embodiment of the application provides an FMCW lidar system, which includes a transmitting module, a beam splitting module, an optical fiber coupling module, a scanning module, and a receiving module, wherein:
  • the transmitting module is used to transmit a laser signal to the beam splitting module
  • the beam splitting module is configured to divide the laser signal into an emission signal and a local oscillator signal, and emit them to the input port of the optical fiber coupling module;
  • the optical fiber coupling module is used to make the output signal received by the input port to output through the transceiver port;
  • the scanning module is used to receive the outgoing signal from the transceiver port of the optical fiber coupling module, and scan it after emitting it outward, and is also used to receive the echo signal and emit it to the optical fiber coupling module.
  • Transceiver port
  • the optical fiber coupling module is further configured to make the local oscillator signal received by the input port and the echo signal received by the transceiver port to obtain an intermediate frequency signal after being coherent, and to emit the intermediate frequency signal through the output port;
  • the receiving module is configured to receive the intermediate frequency signal emitted from the output port of the optical fiber coupling module, and obtain detection information by resolving the intermediate frequency signal according to the intermediate frequency signal.
  • the beam splitting module is a beam splitter, configured to divide the received laser signal into the emission signal and the local oscillation signal, and the energy of the emission signal is greater than the local oscillation signal.
  • the optical fiber coupling module includes a double-clad coupler, and the double-clad coupler includes a first port, a second port, a third port, and a fourth port.
  • the port is the input port
  • the third port is the transceiver port
  • the fourth port is the output port.
  • the optical fiber coupling module further includes a first optical coupler, a second optical coupler, a third optical coupler, and a first transceiver coupler;
  • the first optical coupler is placed at the first port, and the outgoing signal enters the first port through the first optical coupler;
  • the second optical coupler is placed at the second port, and the local oscillator signal enters the second port through the second optical coupler;
  • the first transceiver coupler is placed at the third port, the outgoing signal exits from the third port through the first transceiver coupler, and the echo signal passes through the first transceiver coupler Enter the third port;
  • the third optical coupler is placed at the fourth port, and the intermediate frequency signal exits from the fourth port through the third optical coupler.
  • a double-clad single-mode optical fiber including a first core and a first inner cladding
  • the multimode optical fiber includes a first multimode cladding layer, and the first inner cladding layer and the first multimode cladding layer are welded to form a welded section.
  • the exit signal enters the first core through the first port, and is transmitted to the third port through the first core.
  • the echo signal enters the first inner cladding layer through the third port.
  • the echo signal and the local oscillator signal are coherently obtained in the welding section to obtain the intermediate frequency signal.
  • the beam splitting module is an eccentric fusion splicing optical fiber, including a first optical fiber, a second optical fiber, and a fusion splicing area between the first optical fiber and the second optical fiber
  • the eccentric fusion splicing optical fiber includes a second core And the second cladding; the laser signal enters the second core from the port of the first optical fiber, and when the laser signal is transmitted to the fusion zone, part of the laser signal is transmitted from the second core Enter the second cladding and transmit to the port of the second optical fiber, and the rest of the laser signal is transmitted to the port of the second optical fiber through the second core; the signal emitted from the second cladding Is the local oscillator signal, and the signal emitted by the second core is the emission signal.
  • the optical fiber coupling module includes an optical fiber coupler, the optical fiber coupler includes a fifth port, a sixth port, and a seventh port, the fifth port is the input port, and the sixth port is the For the transceiver port, the seventh port is the output port.
  • the fifth port is fusion spliced with the port of the second optical fiber or connected by an optical fiber connector
  • the optical fiber coupling module further includes a fourth optical coupler and a second transceiver coupler
  • the outgoing signal and the local oscillator signal directly enter the fifth port through the port of the second optical fiber;
  • the second transceiver coupler is placed at the sixth port, the outgoing signal exits from the sixth port through the second transceiver coupler, and the echo signal passes through the second transceiver coupler Enter the sixth port;
  • the fourth optical coupler is placed at the seventh port, and the intermediate frequency signal exits from the seventh port through the fourth optical coupler.
  • the fifth port and the sixth port is a double-clad single-mode optical fiber, including a third core and a third inner cladding, and the seventh port is connected to the third port through a multi-mode optical fiber.
  • the inner cladding is welded, and the multimode optical fiber includes a second multimode cladding.
  • the exit signal enters the third fiber core through the fifth port, and is transmitted to the sixth port through the third fiber core, and the local oscillator signal is transmitted from the fifth port to the sixth port.
  • the port enters the third inner cladding layer.
  • the echo signal enters the third inner cladding layer through the sixth port.
  • the echo signal and the local oscillator signal are coherently obtained in the third inner cladding layer and the second multimode cladding layer to obtain the intermediate frequency signal.
  • the FMCW lidar system is adopted, the 2x2 double-clad fiber coupler is used instead of the circulator or the up-taper fiber is used instead of the circulator, or a high-transmittance circulator can be welded at the exit port of the circulator.
  • the low-reflection micro-mirror structure eliminates the drawbacks of crosstalk and high-intensity echo interference that have to be introduced when the traditional coaxial system needs to use a circulator, and is beneficial to more accurately extract the signal intermediate frequency and demodulate it.
  • the coherent process occurs in the cladding of the optical fiber without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system.
  • the size and volume of the lidar system is greatly reduced, which is easy to integrate and even chip.
  • the total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
  • Fig. 1 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application
  • FIG. 2 is a schematic structural diagram of a double-clad fiber optic coupler provided by an embodiment of the present application
  • Fig. 3 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application.
  • FIG. 4 is a schematic structural diagram of an up-taper fiber provided by an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of a fiber coupling module in an FMCW lidar system with an up-taper fiber structure provided by an embodiment of the present application;
  • Fig. 6 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application.
  • plural means two or more.
  • “And/or” describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone.
  • the character “/” generally indicates that the associated objects before and after are in an "or” relationship.
  • FIG. 1 is a schematic structural diagram of an FMCW lidar system provided in an embodiment of this application.
  • Lidar is a radar system that emits laser beams to detect the target's position, speed and other characteristic quantities. Its working principle is to transmit a detection signal to the target, and then compare the received signal reflected from the target with the transmitted signal. After proper processing, relevant information of the target can be obtained, such as target distance, azimuth, height, speed, Attitude, even shape and other parameters, so as to detect, track and identify aircraft, missiles and other targets. It has been widely used in ranging systems, tracking and measurement of low-flying targets, weapon guidance, atmospheric monitoring, surveying and mapping, early warning, traffic management and other fields.
  • lidar such as Frequency Modulated Continuous Wave (FMCW) lidar
  • FMCW Frequency Modulated Continuous Wave
  • the basic principle is to transmit a continuous wave with a linear change in frequency as the outgoing signal in the sweep period. A part of the outgoing signal is used as the local oscillator signal, and the rest is used as the outgoing signal for detection.
  • the returned echo signal after being reflected by the object is
  • the local oscillator signal has a certain difference in frequency, phase, amplitude, etc.
  • the intermediate frequency signal is obtained through the coherence of the echo signal and the local oscillator signal, and the distance information between the measured object and the lidar can be obtained from the intermediate frequency signal.
  • the FMCW lidar system includes a transmitting module 11, a beam splitting module 12, an optical fiber coupling module 13, a scanning module 14 and a receiving module 15.
  • the transmitting module 11 is composed of various forms of lasers, such as a carbon dioxide laser, a neodymium-doped yttrium aluminum garnet laser, a semiconductor laser, a solid-state laser with tunable wavelength, and a fiber frequency-modulated laser.
  • a light source with continuously changing frequency is required for FMCW lidar.
  • the frequency sweep range is usually from several hundred MHz to several tens of GHz.
  • Triangular waves are generally used for modulation, and the modulation frequency is generally 10 kHz to 100 kHz.
  • FMCW lidar has high requirements for the continuity and linearity of the outgoing signal, so that the difference between the local oscillator signal and the echo signal is stable, avoiding the introduction of other variables due to nonlinear waveform changes.
  • current-modulated distributed feedback (DFB) semiconductor lasers or external cavity semiconductor lasers can be used as the light source.
  • the transmitting module 11 is a fiber frequency modulated laser, which is used to transmit a linearly modulated optical signal to the beam splitting module 12.
  • the beam splitting module 12 is configured to divide the received laser signal into an emission signal and a local oscillation signal, and the energy of the emission signal is greater than the local oscillation signal.
  • the beam splitting module 12 may be a 1*2 beam splitter. One end of the beam splitter is connected to the output end of the transmitting module 11, and the other end of the beam splitter is connected to the input end of the optical fiber coupling module 13.
  • the optical fiber coupling module 13 is used to make the output signal received by the input port output through the transceiver port.
  • the optical fiber coupling module 13 may specifically include a 2x2 double-clad optical fiber coupler that combines a single-mode optical fiber and a multi-mode optical fiber, and the double-clad coupler includes a first port, a second port, a third port, and a fourth port, The first port and the second port are input ports, the third port is a transceiver port, and the fourth port is an output port.
  • the 2x2 double-clad fiber coupler is a coupler that combines a double-clad fiber (a single-mode fiber core is wrapped with a multi-mode inner cladding) and a standard step index multi-mode fiber.
  • the schematic diagram of its internal structure is shown in Figure 2.
  • Between the first port (port 1) and the third port (port 3) is a double-clad single-mode optical fiber, including a first core and a first inner cladding.
  • a multimode optical fiber including a first multimode cladding, and the first inner cladding and the first multimode cladding are welded to form a welded section.
  • the outgoing signal enters the first core through the first port, and is transmitted to the third port through the first core.
  • the echo signal enters the first inner cladding layer through the third port.
  • port 1 is the double-clad single-mode fiber input end
  • port 3 is the double-clad single-mode fiber output end
  • port 2 is the multi-mode fiber input end
  • port 4 is the multi-mode fiber output end.
  • the echo signal and the local oscillator signal are coherently obtained in the welding section to obtain the intermediate frequency signal.
  • the optical fiber coupling module 13 further includes a first optical coupler, a second optical coupler, a third optical coupler, and a first transceiver coupler.
  • the first optical coupler is placed at the first port, the outgoing signal enters the first port through the first optical coupler; the second optical coupler is placed at the second port , The local oscillator signal enters the second port through the second optical coupler; the first transceiver coupler is placed on the third port, and the outgoing signal is transmitted from the second port through the first transceiver coupler.
  • the third port exits, the echo signal enters the third port through the first transceiver coupler; the third optical coupler is placed at the fourth port, and the intermediate frequency signal passes through the The third optical coupler exits from the fourth port.
  • the scanning module 14 is used to receive the outgoing signal from the transceiver port of the optical fiber coupling module, and scan it after emitting it outward, and is also used to receive the echo signal and emit it to all the optical fiber coupling module. ⁇ Transceiver port.
  • the tuned laser outputs a linear frequency-modulated optical signal.
  • one signal After passing through a 1*2 beam splitter, one signal enters the core of the single-mode fiber from port 1 and exits through port 3.
  • the optical collimation system and the scanning system will It is directed to the detected target, and then returns along the same optical path after being reflected by the detected target, and enters the single-mode fiber through the cladding of the single-mode fiber as an echo signal; the other signal is used as a local oscillator signal and passes through optical collimation and expansion.
  • the bundle is coupled into the cladding of the multimode fiber.
  • the echo signal is transmitted from the cladding of the single-mode fiber to the cladding of the multi-mode fiber, and interferes with the local oscillator signal in the cladding of the multi-mode fiber, thereby generating an intermediate frequency signal.
  • the intermediate frequency signal obtained by interference is much lower than the optical frequency.
  • the light is divergent, that is, the outgoing signal will spread more and more after it spreads outward.
  • the outgoing signal is collimated by the optical collimation system, so that the light beam is emitted in an approximately parallel manner.
  • the echo signal before the echo signal enters the cladding, it needs to pass through the transceiver coupler to improve the transmission and reception efficiency. And the echo signal returns along the same optical path as the outgoing signal to realize coaxial transmission and reception, which can reduce interference light.
  • the intermediate frequency signal is generated by the interference of the local oscillator signal and the echo signal. That is, the intermediate frequency signal generated by the local oscillator signal and the echo signal is filtered and detected after being emitted from the cladding, so that the position of the detection target can be determined.
  • the receiving module 15 is configured to receive the intermediate frequency signal emitted from the output port of the optical fiber coupling module, and obtain detection information by resolving the intermediate frequency signal.
  • the receiving module 15 adopts various forms of photodetectors, such as a combination of photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible light multi-element detectors.
  • it further includes a demodulation module 16.
  • the demodulation module 16 includes a data acquisition card and a signal analysis device.
  • the balance detector converts the received intermediate frequency signal into an electrical signal and transmits it to the The data acquisition card is connected, and the data acquisition card is connected with the signal analysis device to process and solve the received electric signal.
  • a photodetector After filtering the noise, a photodetector is used to detect the intermediate frequency signal.
  • a balanced detector can be used for detection.
  • the balanced detector is one of the core components of the coherent detection technology. It adopts the coherent detection technology of the balanced detector, and the receiving sensitivity of the optical detector is about 20dB higher than that of the usual direct detection technology, which significantly eliminates the weak pair of detector noise and electronic circuit noise. The influence of light signal detection.
  • Data acquisition refers to the automatic acquisition of analog or digital signals (detected intermediate frequency signals) of the equipment through the data acquisition card and sends them to the upper computer for analysis and processing, so as to realize the measurement of the distance of the detected target.
  • the data acquisition and processing system is set according to the actual performance requirements of the system.
  • a real-time system requires a high-speed data acquisition card.
  • a 2x2 double-clad fiber coupler is used instead of the circulator, and a linearly modulated optical signal is incident on the core of the single-mode fiber of the 2x2 double-clad fiber coupler to obtain the result.
  • the modulated signal is transmitted to the local oscillator signal of the cladding of the multimode fiber via the core, and the modulated signal is obtained and emitted via the core, and directed toward the detected target via an optical collimation system and a scanning system, And the echo signal coaxially incident on the cladding of the single-mode fiber after being reflected by the detected target, the local oscillator signal and the echo signal interfere in the fused cladding to generate an intermediate frequency signal, which is demodulated
  • the module performs demodulation.
  • the coaxial process of the outgoing signal and the echo signal is completed outside the fiber, the interference of the local oscillator signal and the echo signal is completed in the 2x2 double-clad fiber coupler, and the 2x2 double-clad fiber coupler is inserted inside
  • the loss and echo interference is small, so that the intermediate frequency signal generated by the interference will not be annihilated by the noise, can be demodulated smoothly, and then can accurately measure the position information of the target object.
  • the coherent process occurs in the cladding of the optical fiber without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system.
  • the size and volume of the lidar system is greatly reduced, which is easy to integrate and even chip.
  • the total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
  • FIG. 3 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of this application.
  • the FMCW lidar system includes a transmitting module 21, a beam splitting module 22, an optical fiber coupling module 23, a scanning module 24 and a receiving module 25.
  • the beam splitting module 22 is an eccentric fusion spliced fiber, that is, an up-taper fiber, and the corresponding structure is shown in FIG. 4, including a first fiber, a second fiber, and a gap between the first fiber and the second fiber.
  • the eccentric splicing optical fiber includes a second core and a second cladding; when the laser signal enters the second core from the port of the first optical fiber, and the laser signal is transmitted to the fusion splicing zone , Part of the laser signal enters the second cladding from the second core and is transmitted to the port of the second optical fiber, and the rest of the laser signal is transmitted to the second optical fiber through the second core
  • the port; the signal emitted by the second cladding is the local oscillator signal, and the signal emitted by the second core is the emitted signal.
  • the optical fiber coupling module 23 includes an optical fiber coupler, as shown in FIG. 5, the optical fiber coupler includes a fifth port (port 5), a sixth port (port 6), and a seventh port (port 7). Five ports are the input ports, the sixth port is the transceiver port, and the seventh port is the output port.
  • the fifth port is fusion spliced with the port of the second optical fiber or connected by an optical fiber connector
  • the optical fiber coupling module further includes a fourth optical coupler and a second transceiver coupler; the output signal and the local oscillator signal Enter the fifth port directly through the port of the second optical fiber; the second transceiver coupler is placed at the sixth port, and the outgoing signal passes through the second transceiver coupler from the sixth port Outwardly, the echo signal enters the sixth port through the second transceiver coupler; the fourth optical coupler is placed at the seventh port, and the intermediate frequency signal passes through the fourth optical coupling The device exits from the seventh port.
  • the fifth port and the sixth port is a double-clad single-mode optical fiber, including a third core and a third inner cladding, and the seventh port is welded to the third inner cladding through a multi-mode optical fiber,
  • the multimode optical fiber includes a second multimode cladding.
  • the outgoing signal enters the third fiber core through the fifth port, and is transmitted to the sixth port through the third fiber core, and the local oscillator signal enters the third fiber core through the fifth port.
  • the third inner cladding is used to transmit the third fiber core through the fifth port.
  • the echo signal enters the third inner cladding layer from the sixth port.
  • the echo signal and the local oscillator signal are coherently obtained in the third inner cladding layer and the second multimode cladding layer to obtain the intermediate frequency signal.
  • the fiber frequency-modulated laser outputs a chirped laser signal from the port of the first fiber and enters the up-taper fiber.
  • the laser signal passes through the central fusion splicing area, part of the light is transmitted from the core to the cladding.
  • the light is used as the local oscillator signal of the system, and the remaining laser signal transmitted in the core is used as the output signal of the system.
  • the outgoing signal exits from the port of the second fiber and enters the fiber coupler through port 5, propagates along the third core of the fiber coupler until it exits port 6, and then is directed to the detected target by the optical collimation system and the scanning module After being reflected by the detected target, the echo signal is returned along the same optical path and enters the third inner cladding of the fiber coupler through port 6.
  • the echo signal and the local oscillator signal interfere in the optical fiber cladding, specifically interference in the third inner cladding and the second multimode cladding to generate an intermediate frequency signal.
  • the intermediate frequency signal is emitted from port 7 and received by the receiving module. Although there will be some loss in the propagation of the local oscillator signal, it does not affect the ranging capability of the system.
  • the receiving module 25 adopts various forms of photodetectors, such as a combination of photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible light multi-detector devices, and the like.
  • photodetectors such as a combination of photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible light multi-detector devices, and the like.
  • it is necessary to filter out the noise (such as stray light) in the intermediate frequency signal.
  • it further includes a demodulation module 26 that includes a data acquisition card and a signal analysis device.
  • the balance detector converts the received intermediate frequency signal into an electrical signal and transmits it to the The data acquisition card is connected, and the data acquisition card is connected with the signal analysis device to process and solve the received electric signal.
  • an up-taper fiber is used to replace the circulator, and a linearly modulated laser signal is incident on the core of the up-taper fiber, and part of the laser signal is transmitted to the
  • the cladding of the up-taper fiber is used as the local oscillator signal.
  • the laser signal still transmitted in the core is the exit signal.
  • the local oscillator signal enters the cladding of the fiber coupler, the exit signal enters the core of the fiber coupler, and the exit signal passes through the optics.
  • the collimation system and the scanning system are directed towards the detected target, and the echo signal reflected by the detected target is coaxially incident on the cladding of the fiber coupler, and the local oscillator signal and the echo signal interfere in the cladding of the up-taper fiber
  • the generated intermediate frequency signal is demodulated after being received by the receiving module.
  • the up-taper fiber is used to split the local oscillator signal and the outgoing signal, and the local oscillator signal enters the cladding layer, which provides the basis for the coherence of the subsequent local oscillator signal and echo signal; completed in the cladding layer of the fiber coupler
  • the interference between the local oscillator signal and the echo signal, and the internal insertion loss and interference of the up-taper fiber and the fiber coupler are small, so that the intermediate frequency signal generated by the interference will not be annihilated by noise, can be demodulated smoothly, and can accurately measure the target The location information of the object.
  • the coherent process occurs in the cladding of the fiber coupler without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system.
  • the size and volume of the coherent system are greatly reduced, which is easy to integrate and even chip.
  • the total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
  • FIG. 6 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of this application.
  • the FMCW lidar system includes a transmitting module 31, a beam splitting module 32, an optical fiber coupling module 33, a scanning module 34, and a receiving module 35.
  • the transmitting module 31 is used to transmit a laser signal to the beam splitting module 32;
  • the beam splitting module 32 is used to divide the laser signal into an outgoing signal and a local oscillator signal, and emit them to the input port of the optical fiber coupling module
  • the beam splitting module 32 is a beam splitter, one end is connected to the output end of the transmitting module 21, and the other end is connected to the input end of the optical fiber coupling module 33.
  • the optical fiber coupling module 33 includes a circulator, a first optical coupler, a second optical coupler, and a transmitting lens.
  • the circulator includes an input end, a first output end, and a second output end, wherein:
  • the input terminal and the output terminal of the transmitting module 31 are connected through the first optical coupler, the first output terminal and the scanning module 34 are connected through the transmitting lens, and the second output terminal It is connected with the input end of the receiving module 35 through the second optical coupler.
  • the laser signal enters from port 1 of the circulator and exits from port 3 as the outgoing signal of the radar system.
  • a high-transmission and low-reflection micro-mirror structure can be welded to the exit port 1 of the circulator, so that half of the outgoing signal will be reflected back, and this part of the light will be used as the local oscillator signal of the system.
  • the echo signal of the target object enters through port 3 of the coaxial light-emitting router. At this time, the echo signal and the local oscillator signal interfere in the circulator, and the intermediate frequency signal is output from port 2 to the receiving module.
  • the intermediate frequency signal obtained by coherence is much lower than the optical frequency, and is finally detected by the balanced detector after the noise is filtered by the optical filter.
  • the back-end data acquisition and processing system is set according to the actual performance requirements of the system, and the real-time system needs a high-speed data acquisition card.
  • the advantage of this embodiment is based on a single-mode fiber, but it makes full use of the end face reflection characteristics of the circulator.
  • the receiving module 35 and the demodulating module 36 are similar to the foregoing embodiment, and will not be repeated here.
  • a high-transmission and low-reflection micro-mirror structure is welded at the exit port of the circulator, so that half of the outgoing light of the linear modulated light signal incident on the circulator will be reflected back. This part of the light is used as the local oscillator signal of the system.
  • the outgoing light is reflected by the detection target and coaxially incident on the echo signal of the cladding.
  • the local oscillator signal and the echo signal interfere with the intermediate frequency signal generated in the circulator, and are decoded by the demodulation module. Tune.
  • the end surface reflection characteristics of the circulator are fully utilized, so that the intermediate frequency signal generated by the interference will not be annihilated by noise, can be demodulated smoothly, and can accurately measure the position information of the target object.
  • the size and volume of the coherent system are greatly reduced, which is easy to integrate and even chip, and the total volume of the system is greatly reduced, which is beneficial to reducing the total power consumption of the system.
  • the program can be stored in a computer readable storage medium, and the program can be stored in a computer readable storage medium. During execution, it may include the procedures of the above-mentioned method embodiments.
  • the storage medium can be a magnetic disk, an optical disc, a read-only storage memory or a random storage memory, etc.

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Abstract

An FMCW LIDAR system, the system comprising an emission module (11), an optical fiber coupling module (13), a scanning module (14) and a demodulation module (16). An output terminal of the emission module (11) is connected to an input terminal of the optical fiber coupling module (13), a first output terminal of the optical fiber coupling module (13) is connected to the scanning module (14), and a second output terminal of the optical fiber coupling module (13) is connected to an input terminal of the demodulation module (16).

Description

一种FMCW激光雷达系统A FMCW Lidar System 技术领域Technical field
本申请涉及激光探测技术领域,尤其涉及一种FMCW激光雷达系统。This application relates to the field of laser detection technology, and in particular to an FMCW lidar system.
背景技术Background technique
激光雷达,是以发射激光束探测目标的位置、速度等特征量的雷达系统。其工作原理是向目标发射探测信号,然后将接收到的从目标反射回来的信号与发射信号进行比较,作适当处理后,就可获得目标的有关信息,如目标距离、方位、高度、速度、姿态、甚至形状等参数,从而对飞机、导弹等目标进行探测、跟踪和识别。Lidar is a radar system that emits laser beams to detect the target's position, speed and other characteristic quantities. Its working principle is to transmit a detection signal to the target, and then compare the received signal reflected from the target with the transmitted signal. After proper processing, relevant information of the target can be obtained, such as target distance, azimuth, height, speed, Attitude, even shape and other parameters, so as to detect, track and identify aircraft, missiles and other targets.
对于激光雷达系统,其测距原理是在扫频周期内发射频率线性变化的连续波作为出射信号,出射信号的一部分作为本振信号,其余部分向外出射进行探测,被物体反射后返回的回波信号与本振信号有一定的频率差,通过测量频率差可以获得被探测目标与雷达之间的距离信息。For lidar systems, the principle of ranging is to emit a continuous wave with a linear change in frequency as the outgoing signal in the sweep period, a part of the outgoing signal is used as the local oscillator signal, and the rest is emitted outward for detection, and the return return after being reflected by the object There is a certain frequency difference between the wave signal and the local oscillator signal, and the distance information between the detected target and the radar can be obtained by measuring the frequency difference.
目前,在FMCW激光雷达系统中,常常需要借助环形器完成出射信号的发射与回波信号的接收,环形器往往存在插损和较强的回波干扰从而导致系统的信噪比较低甚至真实的中频信号完全湮没而无法解调,从而导致无法准确的测量目标物体的位置信息。At present, in the FMCW lidar system, it is often necessary to use a circulator to complete the emission of the outgoing signal and the reception of the echo signal. The circulator often has insertion loss and strong echo interference, which leads to the low or even real signal-to-noise ratio of the system. The intermediate frequency signal is completely annihilated and cannot be demodulated, resulting in the inability to accurately measure the position information of the target object.
发明内容Summary of the invention
本申请实施例提供了一种FMCW激光雷达系统,可以顺利解调干涉生成的中频信号,进而能够准确的测量目标物体的位置信息。所述技术方案如下:The embodiment of the present application provides an FMCW lidar system, which can smoothly demodulate the intermediate frequency signal generated by interference, and then can accurately measure the position information of the target object. The technical solution is as follows:
本申请实施例提供了一种FMCW激光雷达系统,所述系统包括发射模块、分束模块、光纤耦合模块、扫描模块和接收模块,其中:The embodiment of the application provides an FMCW lidar system, which includes a transmitting module, a beam splitting module, an optical fiber coupling module, a scanning module, and a receiving module, wherein:
所述发射模块,用于发射激光信号,并射向所述分束模块;The transmitting module is used to transmit a laser signal to the beam splitting module;
所述分束模块,用于将所述激光信号分为出射信号和本振信号,并射向所述光纤耦合模块的输入端口;The beam splitting module is configured to divide the laser signal into an emission signal and a local oscillator signal, and emit them to the input port of the optical fiber coupling module;
所述光纤耦合模块,用于使所述输入端口接收到的所述出射信号通过收发 端口出射;The optical fiber coupling module is used to make the output signal received by the input port to output through the transceiver port;
所述扫描模块,用于接收所述光纤耦合模块的所述收发端口出射的所述出射信号,并向外出射后扫描,还用于接收回波信号并射向所述光纤耦合模块的所述收发端口;The scanning module is used to receive the outgoing signal from the transceiver port of the optical fiber coupling module, and scan it after emitting it outward, and is also used to receive the echo signal and emit it to the optical fiber coupling module. Transceiver port;
所述光纤耦合模块,还用于使所述输入端口接收到的所述本振信号和所述收发端口接收到的所述回波信号相干后得到中频信号,并通过输出端口出射;The optical fiber coupling module is further configured to make the local oscillator signal received by the input port and the echo signal received by the transceiver port to obtain an intermediate frequency signal after being coherent, and to emit the intermediate frequency signal through the output port;
所述接收模块,用于接收所述光纤耦合模块的所述输出端口出射的所述中频信号,并根据所述中频信号解算得到探测信息。The receiving module is configured to receive the intermediate frequency signal emitted from the output port of the optical fiber coupling module, and obtain detection information by resolving the intermediate frequency signal according to the intermediate frequency signal.
可选的,所述分束模块为分束器,用于将接收到的所述激光信号分为所述出射信号和所述本振信号,所述出射信号的能量大于所述本振信号。Optionally, the beam splitting module is a beam splitter, configured to divide the received laser signal into the emission signal and the local oscillation signal, and the energy of the emission signal is greater than the local oscillation signal.
可选的,所述光纤耦合模块包括双包层耦合器,所述双包层耦合器包括第一端口、第二端口、第三端口和第四端口,所述第一端口和所述第二端口为所述输入端口,所述第三端口为所述收发端口,所述第四端口为所述输出端口。Optionally, the optical fiber coupling module includes a double-clad coupler, and the double-clad coupler includes a first port, a second port, a third port, and a fourth port. The port is the input port, the third port is the transceiver port, and the fourth port is the output port.
可选的,所述光纤耦合模块还包括第一光耦合器、第二光耦合器、第三光耦合器以及第一收发耦合器;Optionally, the optical fiber coupling module further includes a first optical coupler, a second optical coupler, a third optical coupler, and a first transceiver coupler;
所述第一光耦合器置于所述第一端口,所述出射信号通过所述第一光耦合器进入所述第一端口;The first optical coupler is placed at the first port, and the outgoing signal enters the first port through the first optical coupler;
所述第二光耦合器置于所述第二端口,所述本振信号通过所述第二光耦合器进入所述第二端口;The second optical coupler is placed at the second port, and the local oscillator signal enters the second port through the second optical coupler;
所述第一收发耦合器置于所述第三端口,所述出射信号通过所述第一收发耦合器从所述第三端口向外出射,所述回波信号通过所述第一收发耦合器进入所述第三端口;The first transceiver coupler is placed at the third port, the outgoing signal exits from the third port through the first transceiver coupler, and the echo signal passes through the first transceiver coupler Enter the third port;
所述第三光耦合器置于所述第四端口,所述中频信号通过所述第三光耦合器从所述第四端口向外出射。The third optical coupler is placed at the fourth port, and the intermediate frequency signal exits from the fourth port through the third optical coupler.
可选的,所述第一端口和所述第三端口之间为双包层单模光纤,包括第一纤芯和第一内包层,所述第二端口和所述第四端口之间为多模光纤,包括第一多模包层,所述第一内包层和所述第一多模包层熔接形成熔接段。Optionally, between the first port and the third port is a double-clad single-mode optical fiber, including a first core and a first inner cladding, and between the second port and the fourth port is The multimode optical fiber includes a first multimode cladding layer, and the first inner cladding layer and the first multimode cladding layer are welded to form a welded section.
可选的,所述出射信号由所述第一端口进入所述第一纤芯,并通过所述第 一纤芯传递至所述第三端口。Optionally, the exit signal enters the first core through the first port, and is transmitted to the third port through the first core.
可选的,所述回波信号由所述第三端口进入所述第一内包层。Optionally, the echo signal enters the first inner cladding layer through the third port.
可选的,所述回波信号和所述本振信号在所述熔接段内相干得到所述中频信号。Optionally, the echo signal and the local oscillator signal are coherently obtained in the welding section to obtain the intermediate frequency signal.
可选的,所述分束模块为偏心熔接光纤,包括第一光纤、第二光纤及所述第一光纤和所述第二光纤之间的熔接区,所述偏心熔接光纤包括第二纤芯和第二包层;所述激光信号由所述第一光纤的端口进入所述第二纤芯,所述激光信号传递至所述熔接区时,部分所述激光信号由所述第二纤芯进入所述第二包层并传输至所述第二光纤的端口,其余所述激光信号通过所述第二纤芯传输至所述第二光纤的端口;由所述第二包层出射的信号为所述本振信号,由所述第二纤芯出射的信号为所述出射信号。Optionally, the beam splitting module is an eccentric fusion splicing optical fiber, including a first optical fiber, a second optical fiber, and a fusion splicing area between the first optical fiber and the second optical fiber, and the eccentric fusion splicing optical fiber includes a second core And the second cladding; the laser signal enters the second core from the port of the first optical fiber, and when the laser signal is transmitted to the fusion zone, part of the laser signal is transmitted from the second core Enter the second cladding and transmit to the port of the second optical fiber, and the rest of the laser signal is transmitted to the port of the second optical fiber through the second core; the signal emitted from the second cladding Is the local oscillator signal, and the signal emitted by the second core is the emission signal.
可选的,所述光纤耦合模块包括光纤耦合器,所述光纤耦合器包括第五端口、第六端口和第七端口,所述第五端口为所述输入端口,所述第六端口为所述收发端口,所述第七端口为所述输出端口。Optionally, the optical fiber coupling module includes an optical fiber coupler, the optical fiber coupler includes a fifth port, a sixth port, and a seventh port, the fifth port is the input port, and the sixth port is the For the transceiver port, the seventh port is the output port.
可选的,所述第五端口与所述第二光纤的端口熔接或通过光纤连接器连接,所述光纤耦合模块还包括第四光耦合器和第二收发耦合器;Optionally, the fifth port is fusion spliced with the port of the second optical fiber or connected by an optical fiber connector, and the optical fiber coupling module further includes a fourth optical coupler and a second transceiver coupler;
所述出射信号和所述本振信号通过由所述第二光纤的端口直接进入所述第五端口;The outgoing signal and the local oscillator signal directly enter the fifth port through the port of the second optical fiber;
所述第二收发耦合器置于所述第六端口,所述出射信号通过所述第二收发耦合器从所述第六端口向外出射,所述回波信号通过所述第二收发耦合器进入所述第六端口;The second transceiver coupler is placed at the sixth port, the outgoing signal exits from the sixth port through the second transceiver coupler, and the echo signal passes through the second transceiver coupler Enter the sixth port;
所述第四光耦合器置于所述第七端口,所述中频信号通过所述第四光耦合器从所述第七端口向外出射。The fourth optical coupler is placed at the seventh port, and the intermediate frequency signal exits from the seventh port through the fourth optical coupler.
可选的,所述第五端口和所述第六端口之间为双包层单模光纤,包括第三纤芯和第三内包层,所述第七端口通过多模光纤与所述第三内包层熔接,所述多模光纤包括第二多模包层。Optionally, between the fifth port and the sixth port is a double-clad single-mode optical fiber, including a third core and a third inner cladding, and the seventh port is connected to the third port through a multi-mode optical fiber. The inner cladding is welded, and the multimode optical fiber includes a second multimode cladding.
可选的,所述所述出射信号由所述第五端口进入所述第三纤芯,并通过所述第三纤芯传递至所述第六端口,所述本振信号由所述第五端口进入所述第三内包层。Optionally, the exit signal enters the third fiber core through the fifth port, and is transmitted to the sixth port through the third fiber core, and the local oscillator signal is transmitted from the fifth port to the sixth port. The port enters the third inner cladding layer.
可选的,所述回波信号由所述第六端口进入所述第三内包层。Optionally, the echo signal enters the third inner cladding layer through the sixth port.
可选的,所述回波信号和所述本振信号在所述第三内包层和所述第二多模包层中相干得到所述中频信号。Optionally, the echo signal and the local oscillator signal are coherently obtained in the third inner cladding layer and the second multimode cladding layer to obtain the intermediate frequency signal.
本申请一些实施例提供的技术方案带来的有益效果至少包括:The beneficial effects brought by the technical solutions provided by some embodiments of the present application include at least:
在本申请一个或多个实施例中,采用FMCW激光雷达系统,采用2x2双包层光纤耦合器替代环形器或采用up-taper光纤替代环形器或在环形器的出射端口处可以熔接一个高透低反的微镜面结构,省去了传统同轴系统需要使用环形器时不得不引入的串扰和高强度回波干扰的弊端,有利于更准确的提取信号中频,并进行解调。此外,相干过程发生在光纤的包层内无需使用3db耦合器,简化了系统的复杂度,有利于降低系统外部引入插损,利于提高系统的信噪比。激光雷达系统尺寸体积大幅减小,便于集成甚至芯片化,系统的总体积大幅减小,有利于降低系统总功耗。In one or more embodiments of this application, the FMCW lidar system is adopted, the 2x2 double-clad fiber coupler is used instead of the circulator or the up-taper fiber is used instead of the circulator, or a high-transmittance circulator can be welded at the exit port of the circulator. The low-reflection micro-mirror structure eliminates the drawbacks of crosstalk and high-intensity echo interference that have to be introduced when the traditional coaxial system needs to use a circulator, and is beneficial to more accurately extract the signal intermediate frequency and demodulate it. In addition, the coherent process occurs in the cladding of the optical fiber without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system. The size and volume of the lidar system is greatly reduced, which is easy to integrate and even chip. The total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
附图说明Description of the drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案,下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍,显而易见地,下面描述中的附图仅仅是本发明的一些实施例,对于本领域普通技术人员来讲,在不付出创造性劳动的前提下,还可以根据这些附图获得其他的附图。In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.
图1是本申请实施例提供的一种FMCW激光雷达系统结构示意图;Fig. 1 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application;
图2是本申请实施例提供的一种双包层光纤耦合器的结构示意图;2 is a schematic structural diagram of a double-clad fiber optic coupler provided by an embodiment of the present application;
图3是本申请实施例提供的一种FMCW激光雷达系统结构示意图;Fig. 3 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application;
图4是本申请实施例提供的一种up-taper光纤的结构示意图;4 is a schematic structural diagram of an up-taper fiber provided by an embodiment of the present application;
图5是本申请实施例提供的一种up-taper光纤结构的FMCW激光雷达系统中光纤耦合模块的结构示意图;5 is a schematic structural diagram of a fiber coupling module in an FMCW lidar system with an up-taper fiber structure provided by an embodiment of the present application;
图6是本申请实施例提供的一种FMCW激光雷达系统结构示意图。Fig. 6 is a schematic structural diagram of an FMCW lidar system provided by an embodiment of the present application.
具体实施方式detailed description
下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本申请一部分实施例,而不是 全部的实施例。基于本申请中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.
在本申请的描述中,需要理解的是,术语“第一”、“第二”等仅用于描述目的,而不能理解为指示或暗示相对重要性。在本申请的描述中,需要说明的是,除非另有明确的规定和限定,“包括”和“具有”以及它们任何变形,意图在于覆盖不排他的包含。例如包含了一系列步骤或单元的过程、方法、系统、产品或设备没有限定于已列出的步骤或单元,而是可选地还包括没有列出的步骤或单元,或可选地还包括对于这些过程、方法、产品或设备固有的其他步骤或单元。对于本领域的普通技术人员而言,可以具体情况理解上述术语在本申请中的具体含义。此外,在本申请的描述中,除非另有说明,“多个”是指两个或两个以上。“和/或”,描述关联对象的关联关系,表示可以存在三种关系,例如,A和/或B,可以表示:单独存在A,同时存在A和B,单独存在B这三种情况。字符“/”一般表示前后关联对象是一种“或”的关系。In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In the description of this application, it should be noted that, unless expressly stipulated and defined otherwise, "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes unlisted steps or units, or optionally also includes Other steps or units inherent to these processes, methods, products or equipment. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood under specific circumstances. In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And/or" describes the association relationship of the associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects before and after are in an "or" relationship.
下面结合具体的实施例对本申请实施例提供的FMCW激光雷达系统进行详细介绍。The FMCW lidar system provided in the embodiments of the present application will be introduced in detail below in conjunction with specific embodiments.
请参见图1,为本申请实施例提供的一种FMCW激光雷达系统的结构示意图。Please refer to FIG. 1, which is a schematic structural diagram of an FMCW lidar system provided in an embodiment of this application.
激光雷达,是以发射激光束探测目标的位置、速度等特征量的雷达系统。其工作原理是向目标发射探测信号,然后将接收到的从目标反射回来的信号与发射信号进行比较,作适当处理后,就可获得目标的有关信息,如目标距离、方位、高度、速度、姿态、甚至形状等参数,从而对飞机、导弹等目标进行探测、跟踪和识别。目前已被广泛应用于测距系统、低飞目标的跟踪测量、武器制导、大气监测、测绘、预警、交通管理等领域。Lidar is a radar system that emits laser beams to detect the target's position, speed and other characteristic quantities. Its working principle is to transmit a detection signal to the target, and then compare the received signal reflected from the target with the transmitted signal. After proper processing, relevant information of the target can be obtained, such as target distance, azimuth, height, speed, Attitude, even shape and other parameters, so as to detect, track and identify aircraft, missiles and other targets. It has been widely used in ranging systems, tracking and measurement of low-flying targets, weapon guidance, atmospheric monitoring, surveying and mapping, early warning, traffic management and other fields.
对于激光雷达,如调频连续波FMCW(Frequency Modulated Continuous Wave,FMCW)激光雷达,属于一种基于相干探测的连续波激光雷达。其基本原理是在扫频周期内发射频率线性变化的连续波作为出射信号,出射信号的一部分作为本振信号,其余部分作为出射信号向外出射进行探测,被物体反射后返回的回波信号与本振信号有一定的频率、相位、幅度等差异,通过回波信 号和本振信号相干得到中频信号,根据中频信号可以获得被测物体与激光雷达之间的距离信息。For lidar, such as Frequency Modulated Continuous Wave (FMCW) lidar, it belongs to a continuous wave lidar based on coherent detection. The basic principle is to transmit a continuous wave with a linear change in frequency as the outgoing signal in the sweep period. A part of the outgoing signal is used as the local oscillator signal, and the rest is used as the outgoing signal for detection. The returned echo signal after being reflected by the object is The local oscillator signal has a certain difference in frequency, phase, amplitude, etc. The intermediate frequency signal is obtained through the coherence of the echo signal and the local oscillator signal, and the distance information between the measured object and the lidar can be obtained from the intermediate frequency signal.
该FMCW激光雷达系统包括发射模块11、分束模块12、光纤耦合模块13、扫描模块14和接收模块15。The FMCW lidar system includes a transmitting module 11, a beam splitting module 12, an optical fiber coupling module 13, a scanning module 14 and a receiving module 15.
其中,发射模块11是各种形式的激光器,如二氧化碳激光器、掺钕钇铝石榴石激光器、半导体激光器及波长可调谐的固体激光器以及光纤调频激光器等组成。在本申请实施例中,对于FMCW激光雷达中,需要一个频率连续变化的光源,扫频范围通常在几百MHz到几十GHz,一般使用三角波进行调制,调制频率一般在10kHz~100kHz。而且FMCW激光雷达对出射信号的连续性和线性度有较高要求,使得本振信号和回波信号之间的差值是稳定的,避免因为波形变化非线性引入其他变量。通常可使用电流调制的分布反馈式(Distributed Feedback,DFB)半导体激光器或外腔半导体激光器(External Cavity Diode Lasers,ECDL)作为光源。所述发射模块11为光纤调频激光器,用于发射线性调制的光信号,并射向所述分束模块12。Among them, the transmitting module 11 is composed of various forms of lasers, such as a carbon dioxide laser, a neodymium-doped yttrium aluminum garnet laser, a semiconductor laser, a solid-state laser with tunable wavelength, and a fiber frequency-modulated laser. In the embodiments of the present application, for FMCW lidar, a light source with continuously changing frequency is required. The frequency sweep range is usually from several hundred MHz to several tens of GHz. Triangular waves are generally used for modulation, and the modulation frequency is generally 10 kHz to 100 kHz. Moreover, FMCW lidar has high requirements for the continuity and linearity of the outgoing signal, so that the difference between the local oscillator signal and the echo signal is stable, avoiding the introduction of other variables due to nonlinear waveform changes. Generally, current-modulated distributed feedback (DFB) semiconductor lasers or external cavity semiconductor lasers (External Cavity Diode Lasers, ECDL) can be used as the light source. The transmitting module 11 is a fiber frequency modulated laser, which is used to transmit a linearly modulated optical signal to the beam splitting module 12.
所述分束模块12,用于将接收到的所述激光信号分为出射信号和本振信号,所述出射信号的能量大于所述本振信号。The beam splitting module 12 is configured to divide the received laser signal into an emission signal and a local oscillation signal, and the energy of the emission signal is greater than the local oscillation signal.
所述分束模块12可以为1*2的分束器。所述分束器的一端与所述发射模块11的输出端相连接,所述分束器的另一端与所述光纤耦合模块13的输入端相连接。The beam splitting module 12 may be a 1*2 beam splitter. One end of the beam splitter is connected to the output end of the transmitting module 11, and the other end of the beam splitter is connected to the input end of the optical fiber coupling module 13.
所述光纤耦合模块13用于使所述输入端口接收到的所述出射信号通过收发端口出射。The optical fiber coupling module 13 is used to make the output signal received by the input port output through the transceiver port.
所述光纤耦合模块13具体可包括单模光纤与多模光纤结合的2x2双包层光纤耦合器,所述双包层耦合器包括第一端口、第二端口、第三端口和第四端口,所述第一端口和所述第二端口为输入端口,所述第三端口为收发端口,所述第四端口为输出端口。The optical fiber coupling module 13 may specifically include a 2x2 double-clad optical fiber coupler that combines a single-mode optical fiber and a multi-mode optical fiber, and the double-clad coupler includes a first port, a second port, a third port, and a fourth port, The first port and the second port are input ports, the third port is a transceiver port, and the fourth port is an output port.
所述2x2双包层光纤耦合器,是双包层光纤(单模光纤纤芯外面包裹了一层多模内包层)与标准阶跃折射率多模光纤结合的耦合器。其内部结构示意图如图2所示,第一端口(端口1)和第三端口(端口3)之间是一根双包层单模光纤,包括第一纤芯和第一内包层,所述第二端口和所述第四端口之间为多 模光纤,包括第一多模包层,所述第一内包层和所述第一多模包层熔接形成熔接段。所述出射信号由所述第一端口进入所述第一纤芯,并通过所述第一纤芯传递至所述第三端口。所述回波信号由所述第三端口进入所述第一内包层。The 2x2 double-clad fiber coupler is a coupler that combines a double-clad fiber (a single-mode fiber core is wrapped with a multi-mode inner cladding) and a standard step index multi-mode fiber. The schematic diagram of its internal structure is shown in Figure 2. Between the first port (port 1) and the third port (port 3) is a double-clad single-mode optical fiber, including a first core and a first inner cladding. Between the second port and the fourth port is a multimode optical fiber, including a first multimode cladding, and the first inner cladding and the first multimode cladding are welded to form a welded section. The outgoing signal enters the first core through the first port, and is transmitted to the third port through the first core. The echo signal enters the first inner cladding layer through the third port.
第二端口(端口2)和第四端口(端口4)之间是一根多模光纤,单模光纤的内包层与多模光纤的包层熔接到一起。也就是说,端口1为双包层单模光纤输入端、端口3为双包层单模光纤输出端、端口2为多模光纤输入端以及端口4为多模光纤输出端。Between the second port (port 2) and the fourth port (port 4) is a multi-mode optical fiber, and the inner cladding of the single-mode optical fiber and the cladding of the multi-mode optical fiber are fused together. That is to say, port 1 is the double-clad single-mode fiber input end, port 3 is the double-clad single-mode fiber output end, port 2 is the multi-mode fiber input end, and port 4 is the multi-mode fiber output end.
所述回波信号和所述本振信号在所述熔接段内相干得到所述中频信号。The echo signal and the local oscillator signal are coherently obtained in the welding section to obtain the intermediate frequency signal.
需要说明的是,所述光纤耦合模块13还包括第一光耦合器、第二光耦合器、第三光耦合器以及第一收发耦合器。其中,所述第一光耦合器置于所述第一端口,所述出射信号通过所述第一光耦合器进入所述第一端口;所述第二光耦合器置于所述第二端口,所述本振信号通过所述第二光耦合器进入所述第二端口;所述第一收发耦合器置于所述第三端口,所述出射信号通过所述第一收发耦合器从所述第三端口向外出射,所述回波信号通过所述第一收发耦合器进入所述第三端口;所述第三光耦合器置于所述第四端口,所述中频信号通过所述第三光耦合器从所述第四端口向外出射。It should be noted that the optical fiber coupling module 13 further includes a first optical coupler, a second optical coupler, a third optical coupler, and a first transceiver coupler. Wherein, the first optical coupler is placed at the first port, the outgoing signal enters the first port through the first optical coupler; the second optical coupler is placed at the second port , The local oscillator signal enters the second port through the second optical coupler; the first transceiver coupler is placed on the third port, and the outgoing signal is transmitted from the second port through the first transceiver coupler. The third port exits, the echo signal enters the third port through the first transceiver coupler; the third optical coupler is placed at the fourth port, and the intermediate frequency signal passes through the The third optical coupler exits from the fourth port.
所述扫描模块14,用于接收所述光纤耦合模块的所述收发端口出射的所述出射信号,并向外出射后扫描,还用于接收回波信号并射向所述光纤耦合模块的所述收发端口。The scanning module 14 is used to receive the outgoing signal from the transceiver port of the optical fiber coupling module, and scan it after emitting it outward, and is also used to receive the echo signal and emit it to all the optical fiber coupling module.述 Transceiver port.
具体的,调谐激光器输出线性调频的光信号,经过1*2的分束器后,一路信号从端口1进入单模光纤的纤芯,经端口3出射,再由光学准直系统和扫描系统将其射向被探测目标,经被探测目标反射后沿相同光路返回,经单模光纤的包层进入单模光纤,作为回波信号;另一路信号作为本振信号,进过光学准直、扩束后被耦合进入多模光纤的包层。回波信号由单模光纤的包层传输至多模光纤的包层中,并与多模光纤的包层中的本振信号发生干涉,从而生成中频信号。干涉得到的中频信号远低于光频。Specifically, the tuned laser outputs a linear frequency-modulated optical signal. After passing through a 1*2 beam splitter, one signal enters the core of the single-mode fiber from port 1 and exits through port 3. The optical collimation system and the scanning system will It is directed to the detected target, and then returns along the same optical path after being reflected by the detected target, and enters the single-mode fiber through the cladding of the single-mode fiber as an echo signal; the other signal is used as a local oscillator signal and passes through optical collimation and expansion. The bundle is coupled into the cladding of the multimode fiber. The echo signal is transmitted from the cladding of the single-mode fiber to the cladding of the multi-mode fiber, and interferes with the local oscillator signal in the cladding of the multi-mode fiber, thereby generating an intermediate frequency signal. The intermediate frequency signal obtained by interference is much lower than the optical frequency.
其中,通常光线是发散的,即出射信号向外传播后会越来越扩散。通过光学准直系统对出射信号进行准直,使光束以近似平行的方式出射。Among them, usually the light is divergent, that is, the outgoing signal will spread more and more after it spreads outward. The outgoing signal is collimated by the optical collimation system, so that the light beam is emitted in an approximately parallel manner.
需要说明的是,回波信号在进入包层前,需要先经过收发耦合器,提高发 射和接收效率。且该回波信号沿与出射信号相同的光路返回,实现同轴收发,可以减少干扰光。It should be noted that before the echo signal enters the cladding, it needs to pass through the transceiver coupler to improve the transmission and reception efficiency. And the echo signal returns along the same optical path as the outgoing signal to realize coaxial transmission and reception, which can reduce interference light.
在本申请实施例中,中频信号通过本振信号与回波信号的干涉生成。即本振信号与回波信号而所生成的中频信号从包层出射后经过滤波、探测等分析处理,从而可以确定探测目标的位置。In the embodiment of the present application, the intermediate frequency signal is generated by the interference of the local oscillator signal and the echo signal. That is, the intermediate frequency signal generated by the local oscillator signal and the echo signal is filtered and detected after being emitted from the cladding, so that the position of the detection target can be determined.
所述接收模块15,用于接收所述光纤耦合模块的所述输出端口出射的所述中频信号,并根据所述中频信号解算得到探测信息。The receiving module 15 is configured to receive the intermediate frequency signal emitted from the output port of the optical fiber coupling module, and obtain detection information by resolving the intermediate frequency signal.
接收模块15采用各种形式的光电探测器,如光电倍增管、半导体光电二极管、雪崩光电二极管、红外和可见光多元探测器件等组合。在本申请实施例中,还包括解调模块16,所述解调模块16包括数据采集卡和信号分析设备,所述平衡探测器将接收到的中频信号转化为电信号后,传输给所述数据采集卡相连接,所述数据采集卡与所述信号分析设备相连接,对接收到的电信号进行处理和解算。The receiving module 15 adopts various forms of photodetectors, such as a combination of photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible light multi-element detectors. In the embodiment of the present application, it further includes a demodulation module 16. The demodulation module 16 includes a data acquisition card and a signal analysis device. The balance detector converts the received intermediate frequency signal into an electrical signal and transmits it to the The data acquisition card is connected, and the data acquisition card is connected with the signal analysis device to process and solve the received electric signal.
为了减小噪声的干扰以及提高测量的准确性,有必要滤除从多模光纤包层输出的中频信号中的噪声(如杂散光),具体可通过信号滤波器滤除。In order to reduce noise interference and improve measurement accuracy, it is necessary to filter out the noise (such as stray light) in the intermediate frequency signal output from the multimode fiber cladding, which can be specifically filtered out by a signal filter.
在滤除噪声后,采用光探测器探测该中频信号。在本申请实施例中,可采用平衡探测器进行探测。平衡探测器是相干探测技术的核心器件之一,采用平衡探测器的相干探测技术,比通常的直接探测技术光探测器的接收灵敏度高约20dB,显著消除了探测器噪声和电子线路噪声对微弱光信号检测的影响。After filtering the noise, a photodetector is used to detect the intermediate frequency signal. In the embodiment of the present application, a balanced detector can be used for detection. The balanced detector is one of the core components of the coherent detection technology. It adopts the coherent detection technology of the balanced detector, and the receiving sensitivity of the optical detector is about 20dB higher than that of the usual direct detection technology, which significantly eliminates the weak pair of detector noise and electronic circuit noise. The influence of light signal detection.
数据采集是指通过数据采集卡对设备被测的模拟或数字信号(所探测到的中频信号)自动采集并送到上位机中进行分析、处理,从而实现对被探测目标距离的测量。Data acquisition refers to the automatic acquisition of analog or digital signals (detected intermediate frequency signals) of the equipment through the data acquisition card and sends them to the upper computer for analysis and processing, so as to realize the measurement of the distance of the detected target.
其中,本申请实施例中,数据采集和处理系统根据系统实际的性能要求设置,一般实时系统需要高速的数据采集卡。Among them, in the embodiment of the present application, the data acquisition and processing system is set according to the actual performance requirements of the system. Generally, a real-time system requires a high-speed data acquisition card.
在本申请一个或多个实施例中,采用2x2双包层光纤耦合器替代环形器,通过将线性调制的光信号入射至2x2双包层光纤耦合器的单模光纤的纤芯中,获取所述调制信号经所述纤芯传输至所述多模光纤的包层的本振信号,并获取所述调制信号经所述纤芯出射,经光学准直系统和扫描系统射向被探测目标,并经所述被探测目标反射后同轴入射至所述单模光纤的包层的回波信号,本振 信号与所述回波信号在融合后的包层中干涉生成中频信号,经解调模块进行解调。在此过程中,在光纤外完成出射信号与回波信号的同轴过程,在2x2双包层光纤耦合器内完成本振信号与回波信号的干涉,而2x2双包层光纤耦合器内部插损和回波干扰较小,使得干涉生成的中频信号不会被噪声湮没,可以顺利解调,进而能够准确的测量目标物体的位置信息。此外,相干过程发生在光纤的包层内无需使用3db耦合器,简化了系统的复杂度,有利于降低系统外部引入插损,利于提高系统的信噪比。激光雷达系统尺寸体积大幅减小,便于集成甚至芯片化,系统的总体积大幅减小,有利于降低系统总功耗。In one or more embodiments of the present application, a 2x2 double-clad fiber coupler is used instead of the circulator, and a linearly modulated optical signal is incident on the core of the single-mode fiber of the 2x2 double-clad fiber coupler to obtain the result. The modulated signal is transmitted to the local oscillator signal of the cladding of the multimode fiber via the core, and the modulated signal is obtained and emitted via the core, and directed toward the detected target via an optical collimation system and a scanning system, And the echo signal coaxially incident on the cladding of the single-mode fiber after being reflected by the detected target, the local oscillator signal and the echo signal interfere in the fused cladding to generate an intermediate frequency signal, which is demodulated The module performs demodulation. In this process, the coaxial process of the outgoing signal and the echo signal is completed outside the fiber, the interference of the local oscillator signal and the echo signal is completed in the 2x2 double-clad fiber coupler, and the 2x2 double-clad fiber coupler is inserted inside The loss and echo interference is small, so that the intermediate frequency signal generated by the interference will not be annihilated by the noise, can be demodulated smoothly, and then can accurately measure the position information of the target object. In addition, the coherent process occurs in the cladding of the optical fiber without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system. The size and volume of the lidar system is greatly reduced, which is easy to integrate and even chip. The total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
请参见图3,为本申请实施例提供的一种FMCW激光雷达系统的结构示意图。该FMCW激光雷达系统包括发射模块21、分束模块22、光纤耦合模块23、扫描模块24和接收模块25。Please refer to FIG. 3, which is a schematic structural diagram of an FMCW lidar system provided by an embodiment of this application. The FMCW lidar system includes a transmitting module 21, a beam splitting module 22, an optical fiber coupling module 23, a scanning module 24 and a receiving module 25.
所述分束模块22为偏心熔接光纤,即up-taper光纤,所对应的结构如图4所示,包括第一光纤、第二光纤及所述第一光纤和所述第二光纤之间的熔接区,所述偏心熔接光纤包括第二纤芯和第二包层;所述激光信号由所述第一光纤的端口进入所述第二纤芯,所述激光信号传递至所述熔接区时,部分所述激光信号由所述第二纤芯进入所述第二包层并传输至所述第二光纤的端口,其余所述激光信号通过所述第二纤芯传输至所述第二光纤的端口;由所述第二包层出射的信号为所述本振信号,由所述第二纤芯出射的信号为所述出射信号。The beam splitting module 22 is an eccentric fusion spliced fiber, that is, an up-taper fiber, and the corresponding structure is shown in FIG. 4, including a first fiber, a second fiber, and a gap between the first fiber and the second fiber. In the fusion splicing zone, the eccentric splicing optical fiber includes a second core and a second cladding; when the laser signal enters the second core from the port of the first optical fiber, and the laser signal is transmitted to the fusion splicing zone , Part of the laser signal enters the second cladding from the second core and is transmitted to the port of the second optical fiber, and the rest of the laser signal is transmitted to the second optical fiber through the second core The port; the signal emitted by the second cladding is the local oscillator signal, and the signal emitted by the second core is the emitted signal.
所述光纤耦合模块23包括光纤耦合器,如图5所示,所述光纤耦合器包括第五端口(端口5)、第六端口(端口6)和第七端口(端口7),所述第五端口为所述输入端口,所述第六端口为所述收发端口,所述第七端口为所述输出端口。The optical fiber coupling module 23 includes an optical fiber coupler, as shown in FIG. 5, the optical fiber coupler includes a fifth port (port 5), a sixth port (port 6), and a seventh port (port 7). Five ports are the input ports, the sixth port is the transceiver port, and the seventh port is the output port.
所述第五端口与所述第二光纤的端口熔接或通过光纤连接器连接,所述光纤耦合模块还包括第四光耦合器和第二收发耦合器;所述出射信号和所述本振信号通过由所述第二光纤的端口直接进入所述第五端口;所述第二收发耦合器置于所述第六端口,所述出射信号通过所述第二收发耦合器从所述第六端口向外出射,所述回波信号通过所述第二收发耦合器进入所述第六端口;所述第四 光耦合器置于所述第七端口,所述中频信号通过所述第四光耦合器从所述第七端口向外出射。The fifth port is fusion spliced with the port of the second optical fiber or connected by an optical fiber connector, and the optical fiber coupling module further includes a fourth optical coupler and a second transceiver coupler; the output signal and the local oscillator signal Enter the fifth port directly through the port of the second optical fiber; the second transceiver coupler is placed at the sixth port, and the outgoing signal passes through the second transceiver coupler from the sixth port Outwardly, the echo signal enters the sixth port through the second transceiver coupler; the fourth optical coupler is placed at the seventh port, and the intermediate frequency signal passes through the fourth optical coupling The device exits from the seventh port.
所述第五端口和所述第六端口之间为双包层单模光纤,包括第三纤芯和第三内包层,所述第七端口通过多模光纤与所述第三内包层熔接,所述多模光纤包括第二多模包层。Between the fifth port and the sixth port is a double-clad single-mode optical fiber, including a third core and a third inner cladding, and the seventh port is welded to the third inner cladding through a multi-mode optical fiber, The multimode optical fiber includes a second multimode cladding.
所述所述出射信号由所述第五端口进入所述第三纤芯,并通过所述第三纤芯传递至所述第六端口,所述本振信号由所述第五端口进入所述第三内包层。The outgoing signal enters the third fiber core through the fifth port, and is transmitted to the sixth port through the third fiber core, and the local oscillator signal enters the third fiber core through the fifth port. The third inner cladding.
所述回波信号由所述第六端口进入所述第三内包层。The echo signal enters the third inner cladding layer from the sixth port.
所述回波信号和所述本振信号在所述第三内包层和所述第二多模包层中相干得到所述中频信号。The echo signal and the local oscillator signal are coherently obtained in the third inner cladding layer and the second multimode cladding layer to obtain the intermediate frequency signal.
具体的,光纤调频激光器输出线性调频的激光信号后从第一光纤的端口入射至up-taper光纤中,当该激光信号经过中心熔接区域时,有部分光从纤芯传递到包层,这部分光作为系统的本振信号,其余留在纤芯中传递的激光信号作为系统的出射信号。出射信号从第二光纤的端口出射并通过端口5进入光纤耦合器,沿光纤耦合器的第三纤芯传播直至从端口6出射,再由光学准直系统和扫描模块将其射向被探测目标,经被探测目标反射后沿相同光路返回回波信号,由端口6进入光纤耦合器的第三内包层。回波信号与本振信号在光纤包层中发生干涉,具体为在第三内包层和第二多模包层中干涉,生成中频信号。最终中频信号从端口7出射并由接收模块接收。尽管本振信号的传播会有部分损耗,但并不影响系统的测距能力。Specifically, the fiber frequency-modulated laser outputs a chirped laser signal from the port of the first fiber and enters the up-taper fiber. When the laser signal passes through the central fusion splicing area, part of the light is transmitted from the core to the cladding. The light is used as the local oscillator signal of the system, and the remaining laser signal transmitted in the core is used as the output signal of the system. The outgoing signal exits from the port of the second fiber and enters the fiber coupler through port 5, propagates along the third core of the fiber coupler until it exits port 6, and then is directed to the detected target by the optical collimation system and the scanning module After being reflected by the detected target, the echo signal is returned along the same optical path and enters the third inner cladding of the fiber coupler through port 6. The echo signal and the local oscillator signal interfere in the optical fiber cladding, specifically interference in the third inner cladding and the second multimode cladding to generate an intermediate frequency signal. Finally, the intermediate frequency signal is emitted from port 7 and received by the receiving module. Although there will be some loss in the propagation of the local oscillator signal, it does not affect the ranging capability of the system.
与前述实施例相似,接收模块25采用各种形式的光电探测器,如光电倍增管、半导体光电二极管、雪崩光电二极管、红外和可见光多元探测器件等组合。为了减小噪声的干扰以及提高测量的准确性,有必要滤除中频信号中的噪声(如杂散光),具体可通过在光电探测器前端设置信号滤波器进行滤除。在本申请实施例中,还包括解调模块26,所述解调模块26包括数据采集卡和信号分析设备,所述平衡探测器将接收到的中频信号转化为电信号后,传输给所述数据采集卡相连接,所述数据采集卡与所述信号分析设备相连接,对接收到的电信号进行处理和解算。Similar to the foregoing embodiment, the receiving module 25 adopts various forms of photodetectors, such as a combination of photomultiplier tubes, semiconductor photodiodes, avalanche photodiodes, infrared and visible light multi-detector devices, and the like. In order to reduce the interference of noise and improve the accuracy of measurement, it is necessary to filter out the noise (such as stray light) in the intermediate frequency signal. Specifically, it can be filtered out by setting a signal filter in the front end of the photodetector. In the embodiment of the present application, it further includes a demodulation module 26 that includes a data acquisition card and a signal analysis device. The balance detector converts the received intermediate frequency signal into an electrical signal and transmits it to the The data acquisition card is connected, and the data acquisition card is connected with the signal analysis device to process and solve the received electric signal.
在本申请一个或多个实施例中,采用up-taper光纤替代环形器,通过将线性调制的激光信号入射至up-taper光纤的纤芯中,部分激光信号经中心熔接区域时传输至所述up-taper光纤的包层作为本振信号,仍在纤芯中传输的激光信号为出射信号,本振信号进入光纤耦合器的包层,出射信号进入光纤耦合器的纤芯,出射信号经过光学准直系统和扫描系统射向被探测目标,并经被探测目标反射的回波信号同轴入射至光纤耦合器的包层,本振信号与回波信号在up-taper光纤的包层中干涉生成的中频信号,经接收模块模块接收后,进行解调。在此过程中,采用up-taper光纤实现本振信号和出射信号的分光,并使本振信号进入包层,为后续本振信号和回波信号相干提供基础;在光纤耦合器的包层完成本振信号与回波信号的干涉,而up-taper光纤和光纤耦合器内部插损和干扰较小,使得干涉生成的中频信号不会被噪声湮没,可以顺利解调,进而能够准确的测量目标物体的位置信息。此外,相干过程发生在光纤耦合器的包层内无需使用3db耦合器,简化了系统的复杂度,有利于降低系统外部引入插损,利于提高系统的信噪比。相干系统尺寸体积大幅减小,便于集成甚至芯片化,系统的总体积大幅减小,有利于降低系统总功耗。In one or more embodiments of the present application, an up-taper fiber is used to replace the circulator, and a linearly modulated laser signal is incident on the core of the up-taper fiber, and part of the laser signal is transmitted to the The cladding of the up-taper fiber is used as the local oscillator signal. The laser signal still transmitted in the core is the exit signal. The local oscillator signal enters the cladding of the fiber coupler, the exit signal enters the core of the fiber coupler, and the exit signal passes through the optics. The collimation system and the scanning system are directed towards the detected target, and the echo signal reflected by the detected target is coaxially incident on the cladding of the fiber coupler, and the local oscillator signal and the echo signal interfere in the cladding of the up-taper fiber The generated intermediate frequency signal is demodulated after being received by the receiving module. In this process, the up-taper fiber is used to split the local oscillator signal and the outgoing signal, and the local oscillator signal enters the cladding layer, which provides the basis for the coherence of the subsequent local oscillator signal and echo signal; completed in the cladding layer of the fiber coupler The interference between the local oscillator signal and the echo signal, and the internal insertion loss and interference of the up-taper fiber and the fiber coupler are small, so that the intermediate frequency signal generated by the interference will not be annihilated by noise, can be demodulated smoothly, and can accurately measure the target The location information of the object. In addition, the coherent process occurs in the cladding of the fiber coupler without using a 3db coupler, which simplifies the complexity of the system, helps reduce the insertion loss introduced outside the system, and improves the signal-to-noise ratio of the system. The size and volume of the coherent system are greatly reduced, which is easy to integrate and even chip. The total volume of the system is greatly reduced, which is beneficial to reduce the total power consumption of the system.
请参见图6,为本申请实施例提供的一种FMCW激光雷达系统的结构示意图。该FMCW激光雷达系统包括发射模块31、分束模块32、光纤耦合模块33、扫描模块34和接收模块35。Please refer to FIG. 6, which is a schematic structural diagram of an FMCW lidar system provided by an embodiment of this application. The FMCW lidar system includes a transmitting module 31, a beam splitting module 32, an optical fiber coupling module 33, a scanning module 34, and a receiving module 35.
所述发射模块31,用于发射激光信号,并射向所述分束模块32;The transmitting module 31 is used to transmit a laser signal to the beam splitting module 32;
所述分束模块32,用于将所述激光信号分为出射信号和本振信号,并射向所述光纤耦合模块的输入端口The beam splitting module 32 is used to divide the laser signal into an outgoing signal and a local oscillator signal, and emit them to the input port of the optical fiber coupling module
所述分束模块32为分束器,一端与所述发射模块21的输出端相连接,另一端与所述光纤耦合模块33的输入端相连接。The beam splitting module 32 is a beam splitter, one end is connected to the output end of the transmitting module 21, and the other end is connected to the input end of the optical fiber coupling module 33.
所述光纤耦合模块33包括环形器、第一光耦合器、第二光耦合器以及发射镜头,所述环形器包括输入端、第一输出端以及第二输出端,其中:The optical fiber coupling module 33 includes a circulator, a first optical coupler, a second optical coupler, and a transmitting lens. The circulator includes an input end, a first output end, and a second output end, wherein:
所述输入端与所述发射模块31的输出端通过所述第一光耦合器相连接,所述第一输出端与所述扫描模块34通过所述发射镜头相连接,所述第二输出端与所述接收模块35的输入端通过所述第二光耦合器相连接。The input terminal and the output terminal of the transmitting module 31 are connected through the first optical coupler, the first output terminal and the scanning module 34 are connected through the transmitting lens, and the second output terminal It is connected with the input end of the receiving module 35 through the second optical coupler.
激光信号从环形器的端口1入射并从端口3出射作为雷达系统的出射信号。在环形器的出射端口1处可以熔接一个高透低反的微镜面结构,这样有一半的出射信号会被反射回来,此部分光作为系统的本振信号。目标物体的回波信号经同轴收发光路由环形器的端口3进入,此时回波信号与本振信号在环形器内部发生干涉,中频信号从端口2输出至接收模块。相干得到的中频信号远低于光频,经光滤波器过滤噪声后最终被平衡探测器探测。后端的数据采集和处理系统根据系统实际的性能要求设置,实时系统需要高速的数据采集卡。该实施例的优势是基于单模光纤的,但是充分利用了环形器的端面反射特性。The laser signal enters from port 1 of the circulator and exits from port 3 as the outgoing signal of the radar system. A high-transmission and low-reflection micro-mirror structure can be welded to the exit port 1 of the circulator, so that half of the outgoing signal will be reflected back, and this part of the light will be used as the local oscillator signal of the system. The echo signal of the target object enters through port 3 of the coaxial light-emitting router. At this time, the echo signal and the local oscillator signal interfere in the circulator, and the intermediate frequency signal is output from port 2 to the receiving module. The intermediate frequency signal obtained by coherence is much lower than the optical frequency, and is finally detected by the balanced detector after the noise is filtered by the optical filter. The back-end data acquisition and processing system is set according to the actual performance requirements of the system, and the real-time system needs a high-speed data acquisition card. The advantage of this embodiment is based on a single-mode fiber, but it makes full use of the end face reflection characteristics of the circulator.
所述接收模块35和解调模块36与前述实施例相似,此处不再赘述。The receiving module 35 and the demodulating module 36 are similar to the foregoing embodiment, and will not be repeated here.
在本申请一个或多个实施例中,在环形器的出射端口处熔接一个高透低反的微镜面结构,这样入射至环形器内的线性调制光信号有一半的出射光会被反射回来,此部分光作为系统的本振信号。而出射光经被探测目标反射后同轴入射至所述包层的回波信号,所述本振信号与所述回波信号在环形器内中干涉生成的中频信号,经解调模块进行解调。在此过程中,充分利用了环形器的端面反射特性,使得干涉生成的中频信号不会被噪声湮没,可以顺利解调,进而能够准确的测量目标物体的位置信息。此外,相干系统尺寸体积大幅减小,便于集成甚至芯片化,系统的总体积大幅减小,有利于降低系统总功耗。In one or more embodiments of the present application, a high-transmission and low-reflection micro-mirror structure is welded at the exit port of the circulator, so that half of the outgoing light of the linear modulated light signal incident on the circulator will be reflected back. This part of the light is used as the local oscillator signal of the system. The outgoing light is reflected by the detection target and coaxially incident on the echo signal of the cladding. The local oscillator signal and the echo signal interfere with the intermediate frequency signal generated in the circulator, and are decoded by the demodulation module. Tune. In this process, the end surface reflection characteristics of the circulator are fully utilized, so that the intermediate frequency signal generated by the interference will not be annihilated by noise, can be demodulated smoothly, and can accurately measure the position information of the target object. In addition, the size and volume of the coherent system are greatly reduced, which is easy to integrate and even chip, and the total volume of the system is greatly reduced, which is beneficial to reducing the total power consumption of the system.
本领域普通技术人员可以理解实现上述实施例方法中的全部或部分流程,是可以通过计算机程序来指令相关的硬件来完成,所述的程序可存储于一计算机可读取存储介质中,该程序在执行时,可包括如上述各方法的实施例的流程。其中,所述的存储介质可为磁碟、光盘、只读存储记忆体或随机存储记忆体等。A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing relevant hardware through a computer program. The program can be stored in a computer readable storage medium, and the program can be stored in a computer readable storage medium. During execution, it may include the procedures of the above-mentioned method embodiments. Wherein, the storage medium can be a magnetic disk, an optical disc, a read-only storage memory or a random storage memory, etc.
以上所揭露的仅为本申请较佳实施例而已,当然不能以此来限定本申请之权利范围,因此依本申请权利要求所作的等同变化,仍属本申请所涵盖的范围。The above-disclosed are only preferred embodiments of this application, and of course the scope of rights of this application cannot be limited by this. Therefore, equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims (15)

  1. 一种FMCW激光雷达系统,其特征在于,所述系统包括发射模块、分束模块、光纤耦合模块、扫描模块和接收模块,其中:An FMCW lidar system, characterized in that the system includes a transmitting module, a beam splitting module, an optical fiber coupling module, a scanning module and a receiving module, wherein:
    所述发射模块,用于发射激光信号,并射向所述分束模块;The transmitting module is used to transmit a laser signal to the beam splitting module;
    所述分束模块,用于将所述激光信号分为出射信号和本振信号,并射向所述光纤耦合模块的输入端口;The beam splitting module is configured to divide the laser signal into an emission signal and a local oscillator signal, and emit them to the input port of the optical fiber coupling module;
    所述光纤耦合模块,用于使所述输入端口接收到的所述出射信号通过收发端口出射;The optical fiber coupling module is used to make the output signal received by the input port output through the transceiver port;
    所述扫描模块,用于接收所述光纤耦合模块的所述收发端口出射的所述出射信号,并向外出射后扫描,还用于接收回波信号并射向所述光纤耦合模块的所述收发端口;The scanning module is used to receive the outgoing signal from the transceiver port of the optical fiber coupling module, and scan it after emitting it outward, and is also used to receive the echo signal and emit it to the optical fiber coupling module. Transceiver port;
    所述光纤耦合模块,还用于使所述输入端口接收到的所述本振信号和所述收发端口接收到的所述回波信号相干后得到中频信号,并通过输出端口出射;The optical fiber coupling module is further configured to make the local oscillator signal received by the input port and the echo signal received by the transceiver port to obtain an intermediate frequency signal after being coherent, and to emit the intermediate frequency signal through the output port;
    所述接收模块,用于接收所述光纤耦合模块的所述输出端口出射的所述中频信号,并根据所述中频信号解算得到探测信息。The receiving module is configured to receive the intermediate frequency signal emitted from the output port of the optical fiber coupling module, and obtain detection information by resolving the intermediate frequency signal according to the intermediate frequency signal.
  2. 根据权利要求1所述的系统,其特征在于,所述分束模块为分束器,用于将接收到的所述激光信号分为所述出射信号和所述本振信号,所述出射信号的能量大于所述本振信号。The system according to claim 1, wherein the beam splitting module is a beam splitter for dividing the received laser signal into the emission signal and the local oscillator signal, and the emission signal The energy of is greater than the local oscillator signal.
  3. 根据权利要求2所述的系统,其特征在于,所述光纤耦合模块包括双包层耦合器,所述双包层耦合器包括第一端口、第二端口、第三端口和第四端口,所述第一端口和所述第二端口为所述输入端口,所述第三端口为所述收发端口,所述第四端口为所述输出端口。The system according to claim 2, wherein the optical fiber coupling module includes a double-clad coupler, and the double-clad coupler includes a first port, a second port, a third port, and a fourth port. The first port and the second port are the input ports, the third port is the transceiver port, and the fourth port is the output port.
  4. 根据权利要求3所述的系统,其特征在于,所述光纤耦合模块还包括第一光耦合器、第二光耦合器、第三光耦合器以及第一收发耦合器;The system according to claim 3, wherein the optical fiber coupling module further comprises a first optical coupler, a second optical coupler, a third optical coupler, and a first transceiver coupler;
    所述第一光耦合器置于所述第一端口,所述出射信号通过所述第一光耦合 器进入所述第一端口;The first optical coupler is placed at the first port, and the outgoing signal enters the first port through the first optical coupler;
    所述第二光耦合器置于所述第二端口,所述本振信号通过所述第二光耦合器进入所述第二端口;The second optical coupler is placed at the second port, and the local oscillator signal enters the second port through the second optical coupler;
    所述第一收发耦合器置于所述第三端口,所述出射信号通过所述第一收发耦合器从所述第三端口向外出射,所述回波信号通过所述第一收发耦合器进入所述第三端口;The first transceiver coupler is placed at the third port, the outgoing signal exits from the third port through the first transceiver coupler, and the echo signal passes through the first transceiver coupler Enter the third port;
    所述第三光耦合器置于所述第四端口,所述中频信号通过所述第三光耦合器从所述第四端口向外出射。The third optical coupler is placed at the fourth port, and the intermediate frequency signal exits from the fourth port through the third optical coupler.
  5. 根据权利要求3所述的系统,其特征在于,所述第一端口和所述第三端口之间为双包层单模光纤,包括第一纤芯和第一内包层,所述第二端口和所述第四端口之间为多模光纤,包括第一多模包层,所述第一内包层和所述第一多模包层熔接形成熔接段。The system according to claim 3, wherein between the first port and the third port is a double-clad single-mode optical fiber, including a first core and a first inner cladding, and the second port Between the fourth port and the fourth port is a multi-mode optical fiber, including a first multi-mode cladding, and the first inner cladding and the first multi-mode cladding are welded to form a welded section.
  6. 根据权利要求5所述的系统,其特征在于,所述出射信号由所述第一端口进入所述第一纤芯,并通过所述第一纤芯传递至所述第三端口。The system according to claim 5, wherein the outgoing signal enters the first core through the first port, and is transmitted to the third port through the first core.
  7. 根据权利要求5所述的系统,其特征在于,所述回波信号由所述第三端口进入所述第一内包层。The system according to claim 5, wherein the echo signal enters the first inner cladding layer through the third port.
  8. 根据权利要求7所述的系统,其特征在于,所述回波信号和所述本振信号在所述熔接段内相干得到所述中频信号。7. The system according to claim 7, wherein the echo signal and the local oscillator signal are coherently obtained in the welding section to obtain the intermediate frequency signal.
  9. 根据权利要求1所述的系统,其特征在于,所述分束模块为偏心熔接光纤,包括第一光纤、第二光纤及所述第一光纤和所述第二光纤之间的熔接区,所述偏心熔接光纤包括第二纤芯和第二包层;所述激光信号由所述第一光纤的端口进入所述第二纤芯,所述激光信号传递至所述熔接区时,部分所述激光信号由所述第二纤芯进入所述第二包层并传输至所述第二光纤的端口,其余所述激光信号通过所述第二纤芯传输至所述第二光纤的端口;由所述第二包层出射 的信号为所述本振信号,由所述第二纤芯出射的信号为所述出射信号。The system according to claim 1, wherein the beam splitting module is an eccentric fusion spliced optical fiber, including a first optical fiber, a second optical fiber, and a fusion splicing area between the first optical fiber and the second optical fiber, so The eccentric fusion spliced optical fiber includes a second core and a second cladding; the laser signal enters the second core from the port of the first optical fiber, and when the laser signal is transmitted to the fusion splicing zone, part of the laser signal The laser signal enters the second cladding from the second core and is transmitted to the port of the second optical fiber, and the rest of the laser signal is transmitted to the port of the second optical fiber through the second core; The signal emitted by the second cladding is the local oscillator signal, and the signal emitted by the second core is the emitted signal.
  10. 根据权利要求9所述的系统,其特征在于,所述光纤耦合模块包括光纤耦合器,所述光纤耦合器包括第五端口、第六端口和第七端口,所述第五端口为所述输入端口,所述第六端口为所述收发端口,所述第七端口为所述输出端口。The system according to claim 9, wherein the optical fiber coupling module includes an optical fiber coupler, the optical fiber coupler includes a fifth port, a sixth port, and a seventh port, and the fifth port is the input Port, the sixth port is the transceiver port, and the seventh port is the output port.
  11. 根据权利要求10所述的系统,其特征在于,所述第五端口与所述第二光纤的端口熔接或通过光纤连接器连接,所述光纤耦合模块还包括第四光耦合器和第二收发耦合器;The system according to claim 10, wherein the fifth port is fusion spliced with the port of the second optical fiber or connected by an optical fiber connector, and the optical fiber coupling module further comprises a fourth optical coupler and a second transceiver Coupler
    所述出射信号和所述本振信号通过由所述第二光纤的端口直接进入所述第五端口;The outgoing signal and the local oscillator signal directly enter the fifth port through the port of the second optical fiber;
    所述第二收发耦合器置于所述第六端口,所述出射信号通过所述第二收发耦合器从所述第六端口向外出射,所述回波信号通过所述第二收发耦合器进入所述第六端口;The second transceiver coupler is placed at the sixth port, the outgoing signal exits from the sixth port through the second transceiver coupler, and the echo signal passes through the second transceiver coupler Enter the sixth port;
    所述第四光耦合器置于所述第七端口,所述中频信号通过所述第四光耦合器从所述第七端口向外出射。The fourth optical coupler is placed at the seventh port, and the intermediate frequency signal exits from the seventh port through the fourth optical coupler.
  12. 根据权利要求10所述的系统,其特征在于,所述第五端口和所述第六端口之间为双包层单模光纤,包括第三纤芯和第三内包层,所述第七端口通过多模光纤与所述第三内包层熔接,所述多模光纤包括第二多模包层。The system according to claim 10, wherein a double-clad single-mode optical fiber is formed between the fifth port and the sixth port, including a third core and a third inner cladding, and the seventh port The multimode optical fiber is fusion spliced with the third inner cladding layer, and the multimode optical fiber includes a second multimode cladding layer.
  13. 根据权利要求12所述的系统,其特征在于,所述所述出射信号由所述第五端口进入所述第三纤芯,并通过所述第三纤芯传递至所述第六端口,所述本振信号由所述第五端口进入所述第三内包层。The system according to claim 12, wherein the exit signal enters the third core through the fifth port, and is transmitted to the sixth port through the third core, so The local oscillator signal enters the third inner cladding layer from the fifth port.
  14. 根据权利要求12所述的系统,其特征在于,所述回波信号由所述第六端口进入所述第三内包层。The system according to claim 12, wherein the echo signal enters the third inner cladding layer from the sixth port.
  15. 根据权利要求14所述的系统,其特征在于,所述回波信号和所述本振信号在所述第三内包层和所述第二多模包层中相干得到所述中频信号。The system according to claim 14, wherein the echo signal and the local oscillator signal are coherently obtained in the third inner cladding layer and the second multimode cladding layer to obtain the intermediate frequency signal.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113721226A (en) * 2021-08-31 2021-11-30 深圳市镭神智能系统有限公司 Frequency modulation continuous wave laser radar
CN114994710A (en) * 2022-08-03 2022-09-02 南京信息工程大学 Dynamic range sectional control laser radar
CN116106862A (en) * 2023-04-10 2023-05-12 深圳市速腾聚创科技有限公司 Optical chip, laser radar, automatic driving system and movable equipment

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115210603B (en) * 2021-10-20 2023-06-23 深圳市速腾聚创科技有限公司 Laser radar and laser radar control method
CN113671464B (en) * 2021-10-22 2022-02-18 杭州视光半导体科技有限公司 Scanning coaxial area array transceiver for on-chip coherence detection

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8908158B2 (en) * 2011-06-30 2014-12-09 Kabushiki Kaisha Topcon Electronic distance measuring method and electronic distance measuring instrument
CN105470798A (en) * 2016-01-29 2016-04-06 成都信息工程大学 Linear frequency modulation single frequency pulse optical fiber laser device
CN105572803A (en) * 2016-03-28 2016-05-11 中国人民解放军国防科学技术大学 Fusion tapered optical fiber power beam combiner and manufacturing method thereof
CN106886031A (en) * 2017-02-27 2017-06-23 南京红露麟激光雷达科技有限公司 The Rayleigh Doppler anemometry laser radar of coherent detection is gated based on wide range
CN108490597A (en) * 2018-06-05 2018-09-04 张红明 A kind of confocal microscope system based on fiber coupler
CN109073755A (en) * 2016-01-27 2018-12-21 三菱电机株式会社 coherent laser radar device
CN109350012A (en) * 2018-11-28 2019-02-19 中国计量大学 A kind of fluorescent material detection system based on doubly clad optical fiber
CN109946707A (en) * 2019-03-15 2019-06-28 深圳市速腾聚创科技有限公司 Laser radar reception device, emitter, system and distance measurement method

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100578261C (en) * 2007-02-02 2010-01-06 北京航空航天大学 Continuous wave frequency adjustment coherent optical fiber laser radar
US8946637B2 (en) * 2010-11-23 2015-02-03 The United States Of America As Represented By The Secretary Of The Army Compact fiber-based scanning laser detection and ranging system
CN106707291B (en) * 2016-12-09 2020-01-03 中国科学技术大学 Double-frequency linear frequency modulation coherent wind lidar
WO2019183838A1 (en) * 2018-03-28 2019-10-03 深圳市太赫兹科技创新研究院 Optical coherence tomography system
CN108508535A (en) * 2018-04-04 2018-09-07 东北大学 A kind of production method of the 1x2 fiber optic splitters based on convex cone welding
CN110261844A (en) * 2019-07-22 2019-09-20 北京因泰立科技有限公司 It is a kind of to receive and dispatch coaxial multi-line laser radar

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8908158B2 (en) * 2011-06-30 2014-12-09 Kabushiki Kaisha Topcon Electronic distance measuring method and electronic distance measuring instrument
CN109073755A (en) * 2016-01-27 2018-12-21 三菱电机株式会社 coherent laser radar device
CN105470798A (en) * 2016-01-29 2016-04-06 成都信息工程大学 Linear frequency modulation single frequency pulse optical fiber laser device
CN105572803A (en) * 2016-03-28 2016-05-11 中国人民解放军国防科学技术大学 Fusion tapered optical fiber power beam combiner and manufacturing method thereof
CN106886031A (en) * 2017-02-27 2017-06-23 南京红露麟激光雷达科技有限公司 The Rayleigh Doppler anemometry laser radar of coherent detection is gated based on wide range
CN108490597A (en) * 2018-06-05 2018-09-04 张红明 A kind of confocal microscope system based on fiber coupler
CN109350012A (en) * 2018-11-28 2019-02-19 中国计量大学 A kind of fluorescent material detection system based on doubly clad optical fiber
CN109946707A (en) * 2019-03-15 2019-06-28 深圳市速腾聚创科技有限公司 Laser radar reception device, emitter, system and distance measurement method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113721226A (en) * 2021-08-31 2021-11-30 深圳市镭神智能系统有限公司 Frequency modulation continuous wave laser radar
CN114994710A (en) * 2022-08-03 2022-09-02 南京信息工程大学 Dynamic range sectional control laser radar
CN114994710B (en) * 2022-08-03 2022-10-28 南京信息工程大学 Dynamic range sectional control laser radar
CN116106862A (en) * 2023-04-10 2023-05-12 深圳市速腾聚创科技有限公司 Optical chip, laser radar, automatic driving system and movable equipment
CN116106862B (en) * 2023-04-10 2023-08-04 深圳市速腾聚创科技有限公司 Optical chip, laser radar, automatic driving system and movable equipment

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