CN115015966A - Gas detection laser radar based on wide-spectrum light source - Google Patents

Gas detection laser radar based on wide-spectrum light source Download PDF

Info

Publication number
CN115015966A
CN115015966A CN202210934522.3A CN202210934522A CN115015966A CN 115015966 A CN115015966 A CN 115015966A CN 202210934522 A CN202210934522 A CN 202210934522A CN 115015966 A CN115015966 A CN 115015966A
Authority
CN
China
Prior art keywords
gas
light source
module
spectrum light
absorption
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210934522.3A
Other languages
Chinese (zh)
Other versions
CN115015966B (en
Inventor
夏海云
章振
余赛芬
董晶晶
胡佳栋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujian Ruicarbon Optoelectronic Precision Instrument Co ltd
Original Assignee
Nanjing University of Information Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanjing University of Information Science and Technology filed Critical Nanjing University of Information Science and Technology
Priority to CN202210934522.3A priority Critical patent/CN115015966B/en
Publication of CN115015966A publication Critical patent/CN115015966A/en
Application granted granted Critical
Publication of CN115015966B publication Critical patent/CN115015966B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • G01S17/88Lidar systems specially adapted for specific applications
    • G01S17/95Lidar systems specially adapted for specific applications for meteorological use
    • 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
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Electromagnetism (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

本申请提供一种基于宽谱光源的气体探测激光雷达,涉及激光雷达技术领域,该气体探测激光雷达使用宽谱激光器作为激光源,通过多通道滤波器滤出多个波长的激光用于探测气体光谱,并在接收时采用波分复用器进行多个波长的解复用和多个波长的同时探测,获得距离分辨和光谱分辨的待测气体吸收线。该发明使用光通信器件完成宽谱的大气气体成分遥感,具有如下优势:首先,不需要多个单频激光器,并且宽谱光源可进一步提高出射功率,降低系统成本;其次,多个波长的回波信号同步探测,获得待测气体吸收光谱的同时拥有高时空分辨率;最后,全光纤化的系统有利于集成化和小型化。

Figure 202210934522

The application provides a gas detection lidar based on a broad-spectrum light source, and relates to the technical field of lidar. The gas detection lidar uses a broad-spectrum laser as a laser source, and filters out lasers with multiple wavelengths through a multi-channel filter for gas detection. When receiving, the wavelength division multiplexer is used for demultiplexing of multiple wavelengths and simultaneous detection of multiple wavelengths to obtain distance-resolved and spectral-resolved absorption lines of the gas to be tested. The invention uses optical communication devices to complete wide-spectrum atmospheric gas composition remote sensing, and has the following advantages: firstly, multiple single-frequency lasers are not required, and the broadband light source can further increase the output power and reduce the system cost; secondly, the return of multiple wavelengths The wave signal is detected synchronously, and the absorption spectrum of the gas to be measured is obtained with high temporal and spatial resolution; finally, the all-fiber system is conducive to integration and miniaturization.

Figure 202210934522

Description

一种基于宽谱光源的气体探测激光雷达A Gas Detection Lidar Based on Broad Spectrum Light Source

技术领域technical field

本发明涉及激光雷达领域,更具体地说,涉及一种基于宽谱光源的气体探测激光雷达。The invention relates to the field of laser radar, and more particularly, to a gas detection laser radar based on a broad-spectrum light source.

背景技术Background technique

大气气体成分遥感对气象气候研究、污染物监测和大气光化学反应研究等有重要意义。Remote sensing of atmospheric gas composition is of great significance to meteorological and climate research, pollutant monitoring and atmospheric photochemical reaction research.

目前的大气气体成分测量主要依靠原位测量设备和激光雷达,虽然原位测量技术能够获得高精度的多种气体成分,但是无法获得三维空间分布的气体成分测量,难以定位气体污染的源头和气体的传播过程,激光雷达是实现大气气体成分三维遥感的有效途径。At present, the measurement of atmospheric gas composition mainly relies on in-situ measurement equipment and lidar. Although in-situ measurement technology can obtain high-precision various gas compositions, it cannot obtain gas composition measurement of three-dimensional spatial distribution, and it is difficult to locate the source of gas pollution and gas. Lidar is an effective way to realize 3D remote sensing of atmospheric gas composition.

本发明的发明人发现,气体探测激光雷达主要采用差分吸收激光雷达、路径积分差分吸收激光雷达和高光谱分辨激光雷达。差分吸收激光雷达选用两个波长的激光,一个位于待测气体吸收截面强的位置,另一个位于待测气体吸收截面弱的位置。用于差分吸收激光雷达的激光器需要有较窄的线宽和较高的波长稳定度,并且对于不同的待测气体需要不同的激光器,因此差分吸收激光雷达系统成本较高。基于高光谱分辨的波长扫描激光雷达,通过扫描光谱,可获得多种气体吸收光谱,如专利申请号为CN201710651695.3的发明专利提供的基于波长可调谐激光器的气体成分探测激光雷达。但其在扫描过程中需要实时的激光波长锁定和校准,系统复杂且扫描过程耗时导致时间分辨率低。The inventor of the present invention found that the gas detection laser radar mainly adopts differential absorption laser radar, path integral differential absorption laser radar and hyperspectral resolution laser radar. Differential absorption lidar uses two wavelengths of laser light, one is located at the position where the absorption cross-section of the gas to be measured is strong, and the other is located at the position where the absorption cross-section of the gas to be measured is weak. The laser used for differential absorption lidar needs to have narrow linewidth and high wavelength stability, and different lasers are required for different gases to be measured, so the cost of differential absorption lidar system is high. Based on the wavelength scanning lidar with hyperspectral resolution, a variety of gas absorption spectra can be obtained by scanning the spectrum. However, it requires real-time laser wavelength locking and calibration during the scanning process. The system is complex and the scanning process is time-consuming, resulting in low time resolution.

发明内容SUMMARY OF THE INVENTION

(一)解决的技术问题(1) Technical problems solved

本发明目的为提供一种基于宽谱光源的气体探测激光雷达,用于解决现有激光雷达在扫描过程中需要实时的激光波长锁定和校准,系统复杂且扫描过程耗时导致时间分辨率低的问题。The object of the present invention is to provide a gas detection laser radar based on a broad-spectrum light source, which is used to solve the problem that the existing laser radar needs real-time laser wavelength locking and calibration during the scanning process, and the system is complex and the scanning process is time-consuming, resulting in low time resolution. question.

(二)技术方案(2) Technical solutions

为实现以上目的,本发明通过以下技术方案予以实现:一种基于宽谱光源的气体探测激光雷达,其特征在于,包括:宽谱光源、多通道滤波器、脉冲发生和功率放大模块、激光束收发模块、解波分复用模块、多通道探测模块、数据采集模块和数据处理模块;In order to achieve the above purpose, the present invention is achieved through the following technical solutions: a gas detection laser radar based on a broad-spectrum light source, characterized in that it includes: a broad-spectrum light source, a multi-channel filter, a pulse generation and power amplification module, a laser beam Transceiver module, demultiplexing module, multi-channel detection module, data acquisition module and data processing module;

其中,所述宽谱光源用于出射宽谱激光;Wherein, the broad-spectrum light source is used to emit broad-spectrum laser light;

所述多通道滤波器用于将宽谱光源出射的宽谱激光滤出多个不同频率的激光信号,多个不同频率分别对应待测气体吸收曲线的不同位置;其中,滤出的每个频率对应的曲线的半高全宽均小于预设的阈值;待测气体包含一种或多种气体;The multi-channel filter is used to filter out a plurality of laser signals of different frequencies from the broad-spectrum laser emitted by the broad-spectrum light source, and the plurality of different frequencies correspond to different positions of the absorption curve of the gas to be measured; wherein, each filtered frequency corresponds to The full width at half maximum of the curve is less than the preset threshold; the gas to be tested contains one or more gases;

所述脉冲发生和功率放大模块用于将宽谱光源输出的连续光斩成脉冲光并通过激光放大器将脉冲光进行功率放大;The pulse generating and power amplifying module is used for chopping the continuous light output by the broad-spectrum light source into pulsed light and amplifying the power of the pulsed light through a laser amplifier;

所述激光束收发模块用于出射放大后的激光脉冲至待测气体,并接收激光在待测气体中的后向散射信号;The laser beam transceiver module is used for outputting amplified laser pulses to the gas to be measured, and receiving backscattered signals of the laser in the gas to be measured;

所述解波分复用模块用于将多个频率的激光后向散射信号解复用至对应的多个光纤信号通道中,不同的光纤信号通道对应不同的信号频率;The demultiplexing module is used for demultiplexing the laser backscattered signals of multiple frequencies into corresponding multiple optical fiber signal channels, and different optical fiber signal channels correspond to different signal frequencies;

所述多通道探测模块包括多个探测通道,用于探测所述解波分复用模块解复用后的多个光纤信号通道中的信号,输出相应的电信号;The multi-channel detection module includes a plurality of detection channels, which are used for detecting signals in the plurality of optical fiber signal channels demultiplexed by the demultiplexing module, and outputting corresponding electrical signals;

所述数据采集模块用于采集所述多通道探测模块输出的电信号;The data acquisition module is used to collect electrical signals output by the multi-channel detection module;

所述数据处理模块用于处理所述数据采集模块采集到的多个频率的回波信号,反演待测气体在不同距离处的吸收光谱,计算不同距离处的气体浓度。The data processing module is used for processing the echo signals of multiple frequencies collected by the data acquisition module, inverting the absorption spectrum of the gas to be measured at different distances, and calculating the gas concentration at different distances.

进一步的,所述宽谱光源为紫外至红外波段的宽谱光源。Further, the broad-spectrum light source is a broad-spectrum light source in the ultraviolet to infrared wavelength band.

进一步的,所述多通道滤波器为法布里珀罗干涉仪;所述预设的阈值为100MHz。Further, the multi-channel filter is a Fabry-Perot interferometer; the preset threshold is 100 MHz.

进一步的,所述激光束收发模块包括环形器和望远镜,所述环形器用于出射所述放大后的激光脉冲至所述望远镜,所述环形器还用于将所述望远镜接收回的待测气体的后向散射信号传输至所述解波分复用模块;所述望远镜用于出射激光束至待测气体中和接收待测气体的后向散射信号。Further, the laser beam transceiver module includes a circulator and a telescope, the circulator is used to emit the amplified laser pulses to the telescope, and the circulator is also used to receive the gas to be measured back by the telescope. The backscattered signal is transmitted to the demultiplexing module; the telescope is used to emit the laser beam to the gas to be tested and receive the backscattered signal of the gas to be tested.

进一步的,所述解波分复用模块为WDM波分复用器或色散光栅。Further, the demultiplexing module is a WDM wavelength division multiplexer or a dispersion grating.

进一步的,所述解波分复用模块包括多个输出端,所述多通道探测模块包括对应的多个探测通道,每个探测通道用于探测对应的一个解波分复用模块输出端输出的信号。Further, the de-wavelength division multiplexing module includes a plurality of output terminals, the multi-channel detection module includes a plurality of corresponding detection channels, and each detection channel is used to detect a corresponding output end of the de-wavelength division multiplexing module. signal of.

进一步的,所述多通道探测模块包括与宽谱光源输出波段对应的多通道光电探测器。Further, the multi-channel detection module includes a multi-channel photodetector corresponding to the output band of the broad-spectrum light source.

进一步的,所述多通道探测模块包括多个光电探测器。Further, the multi-channel detection module includes a plurality of photodetectors.

进一步的,光电探测器为光电倍增管、硅探测器、铟镓砷探测器或碲镉汞探测器。Further, the photodetector is a photomultiplier tube, a silicon detector, an indium gallium arsenide detector or a mercury cadmium telluride detector.

进一步的,所述数据处理模块采用洛伦兹曲线拟合算法进行待测气体浓度反演,对多通道回波信号进行洛伦兹曲线拟合获得待测气体吸收曲线的面积,根据所述面积计算待测气体的浓度。Further, the data processing module uses the Lorentz curve fitting algorithm to invert the concentration of the gas to be measured, and performs Lorentz curve fitting on the multi-channel echo signal to obtain the area of the absorption curve of the gas to be measured. Calculate the concentration of the gas to be measured.

进一步的,所述数据处理模块包括非线性拟合单元和气体浓度计算单元;Further, the data processing module includes a nonlinear fitting unit and a gas concentration calculation unit;

所述非线性拟合单元用于根据所述数据采集模块采集到的多个频率的回波信号得到不同距离处的吸收光谱,并对所述吸收光谱进行非线性拟合,获得拟合曲线;The nonlinear fitting unit is configured to obtain absorption spectra at different distances according to the echo signals of multiple frequencies collected by the data acquisition module, and perform nonlinear fitting on the absorption spectra to obtain a fitting curve;

所述气体浓度计算单元用于计算所述拟合曲线的面积,根据所述面积计算待测气体的浓度。The gas concentration calculation unit is configured to calculate the area of the fitting curve, and calculate the concentration of the gas to be measured according to the area.

进一步的,对所述吸收光谱进行非线性拟合,包括:Further, performing nonlinear fitting on the absorption spectrum, including:

对所述吸收光谱采用洛伦兹曲线拟合;applying Lorentzian curve fitting to the absorption spectrum;

若吸收光谱中包含一个吸收峰,则对所述吸收光谱采用单峰洛伦兹曲线拟合;If the absorption spectrum contains one absorption peak, then fitting the absorption spectrum with a single-peak Lorentzian curve;

若吸收光谱中包含多个吸收峰,则对所述吸收光谱采用多峰洛伦兹曲线拟合。If the absorption spectrum contains multiple absorption peaks, a multi-peak Lorentzian curve fitting is used for the absorption spectrum.

(三)有益效果(3) Beneficial effects

(1)本发明一种基于宽谱光源的气体探测激光雷达,通过采用宽谱光源,克服了采用传统激光雷达由于要求窄线宽光源造成的受激布里渊散射效应强,进而对激光器的输出功率的限制,因此宽谱光源可以实现显著提高激光雷达的功率和信噪比。本发明采用宽谱光源配合多通道滤波模块,不需要配置多个光源,成本低,覆盖光谱范围宽,可同时探测多种气体。此外,相比现有激光雷达的窄线宽光源,本发明采用宽谱光源成本低,具有很大的价格优势。(1) The present invention is a gas detection laser radar based on a wide-spectrum light source. By using a wide-spectrum light source, it overcomes the strong stimulated Brillouin scattering effect caused by the narrow linewidth light source required by the traditional laser radar, and further reduces the impact on the laser beam. The output power is limited, so broad-spectrum light sources can achieve significant improvements in lidar power and signal-to-noise ratio. The invention adopts a broad-spectrum light source and a multi-channel filter module, does not need to configure multiple light sources, has low cost, covers a wide spectrum range, and can detect multiple gases at the same time. In addition, compared with the narrow linewidth light source of the existing laser radar, the present invention adopts a wide spectrum light source with low cost and has a great price advantage.

(2)本发明一种基于宽谱光源的气体探测激光雷达,通过采用多通道滤波器滤出多个不同频率的激光进行探测,能够实现多种成分的气体光谱同时探测,采用本发明的方法,只需要一次测量,不需要对光谱进行扫描,不需要实时的激光波长锁定和校准,大大简化了多气体成分同时探测系统的复杂度,测量速度快,耗时少,可以做到准实时测量,显著提高了时间分辨率。(2) The present invention is a gas detection laser radar based on a broad-spectrum light source. By using a multi-channel filter to filter out a plurality of lasers of different frequencies for detection, it can realize the simultaneous detection of gas spectra of various components. The method of the present invention is adopted. , only one measurement, no need to scan the spectrum, no real-time laser wavelength locking and calibration, which greatly simplifies the complexity of the simultaneous detection system for multiple gas components, fast measurement speed, less time-consuming, and can achieve quasi-real-time measurement , significantly improving the temporal resolution.

(3)本发明一种基于宽谱光源的气体探测激光雷达,本发明的解波分复用器将多个频率的大气回波信号传输至多通道探测器进行信号的探测,从而完成高时空分辨率的气体光谱的探测。(3) The present invention is a gas detection laser radar based on a broad-spectrum light source. The demultiplexer of the present invention transmits atmospheric echo signals of multiple frequencies to a multi-channel detector for signal detection, thereby achieving high temporal and spatial resolution. Detection of gas spectra at rates.

(4)本发明一种基于宽谱光源的气体探测激光雷达,本发明的数据处理模块采用洛伦兹曲线拟合算法进行待测气体浓度反演,对多通道回波信号进行洛伦兹曲线拟合以获得待测气体吸收曲线的面积,根据面积计算待测气体的浓度,能够获得更高的探测精度。(4) The present invention is a gas detection laser radar based on a broad-spectrum light source. The data processing module of the present invention uses the Lorentz curve fitting algorithm to invert the concentration of the gas to be measured, and performs the Lorentz curve on the multi-channel echo signals. Fitting to obtain the area of the absorption curve of the gas to be measured, and calculating the concentration of the gas to be measured according to the area, higher detection accuracy can be obtained.

附图说明Description of drawings

图1为本发明实施例提供的基于宽谱光源的气体探测激光雷达的结构示意图;1 is a schematic structural diagram of a gas detection lidar based on a broad-spectrum light source provided by an embodiment of the present invention;

图2为本发明实施例提供的某一位置的宽谱光源光谱图;FIG. 2 is a spectrogram of a broad-spectrum light source at a certain position provided by an embodiment of the present invention;

图3为本发明实施例提供的某一位置的光源经多通道滤波器后的光谱图;3 is a spectrogram of a light source at a certain position provided by an embodiment of the present invention after being subjected to a multi-channel filter;

图4为本发明实施例提供的某一位置的大气气体吸收线;4 is an atmospheric gas absorption line at a certain position provided by an embodiment of the present invention;

图5为本发明实施例提供的不同波长的雷达回波信号;FIG. 5 is radar echo signals of different wavelengths provided by an embodiment of the present invention;

图6为本发明实施例提供的解波分复用器各通道的透过率曲线;6 is a transmittance curve of each channel of a demultiplexer provided by an embodiment of the present invention;

图7为本发明实施例提供的某一位置的数据处理后的多波长探测的待测气体吸收强度,以及非线性拟合的气体吸收光谱;Fig. 7 is the gas absorption intensity of the gas to be detected by multi-wavelength detection after data processing at a certain position provided by the embodiment of the present invention, and the gas absorption spectrum of nonlinear fitting;

图8为本发明实施例中待测气体包含两种气体时,测量得到的不同距离处的吸收光谱。FIG. 8 is an absorption spectrum obtained by measurement at different distances when the gas to be measured contains two gases in an embodiment of the present invention.

图9为本发明实施例中待测气体包含两种气体时,则对不同距离处的吸收光谱采用双峰洛伦兹曲线拟合后的拟合曲线。FIG. 9 is a fitting curve obtained by fitting the absorption spectra at different distances by a bimodal Lorentzian curve when the gas to be tested contains two gases in the embodiment of the present invention.

其中,1、宽谱光源;2、多通道滤波器;3、脉冲发生和功率放大模块;4、功率放大模块;20、激光束收发模块;5、环形器;6、望远镜;7、解波分复用模块;8、多通道探测模块;9、数据采集模块;10、数据处理模块。Among them, 1. Broad-spectrum light source; 2. Multi-channel filter; 3. Pulse generation and power amplification module; 4. Power amplification module; 20. Laser beam transceiver module; 5. Circulator; 6. Telescope; 7. Dewave Multiplexing module; 8. Multi-channel detection module; 9. Data acquisition module; 10. Data processing module.

具体实施方式Detailed ways

下面将结合本发明的附图,对本发明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发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,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,都属于本发明保护的范围。The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

实施例Example

参考图1,图1为本发明实施例提供的一种基于宽谱光源的气体探测激光雷达的结构示意图,所述气体探测激光雷达包括:宽谱光源1、多通道滤波器2、脉冲发生和功率放大模块3、功率放大模块4、激光束收发模块20、解波分复用模块7、多通道探测模块8、数据采集模块9和数据处理模块10。Referring to FIG. 1, FIG. 1 is a schematic structural diagram of a gas detection lidar based on a broad-spectrum light source provided by an embodiment of the present invention. The gas detection lidar includes: a broad-spectrum light source 1, a multi-channel filter 2, a pulse generator and a Power amplification module 3 , power amplification module 4 , laser beam transceiver module 20 , wavelength division multiplexing module 7 , multi-channel detection module 8 , data acquisition module 9 and data processing module 10 .

宽谱光源的输出端与多通道滤波器的输出端连接,多通道滤波器的输出端与脉冲发生和功率放大模块的输入端连接,功率放大模块的输出端与激光束收发模块的输入端连接;激光束收发模块的输出端与解波分复用模块的输入端连接,解波分复用模块的输出端与多通道探测模块的输入端连接;上述连接均为光纤连接。多通道探测模块、数据采集模块和数据处理模块依次连接。The output end of the broad-spectrum light source is connected with the output end of the multi-channel filter, the output end of the multi-channel filter is connected with the input end of the pulse generation and power amplifying module, and the output end of the power amplifying module is connected with the input end of the laser beam transceiver module The output end of the laser beam transceiver module is connected with the input end of the demultiplexing module, and the output end of the demultiplexing module is connected with the input end of the multi-channel detection module; the above connections are all optical fiber connections. The multi-channel detection module, the data acquisition module and the data processing module are connected in sequence.

其中,所述宽谱光源1用于出射宽谱激光。非传统激光雷达要求的窄线宽光源,线宽越窄,受激布里渊散射效应越强,从而限制了激光器的输出功率。而宽谱光源成本低,且光谱线宽较宽,受激布里渊散射效应较弱,因此可以提高光源功率。Wherein, the broad-spectrum light source 1 is used for emitting broad-spectrum laser light. For the narrow linewidth light source required by non-traditional lidar, the narrower the linewidth, the stronger the stimulated Brillouin scattering effect, thus limiting the output power of the laser. The broad-spectrum light source has low cost, wide spectral linewidth, and weak stimulated Brillouin scattering effect, so the power of the light source can be increased.

在一个实施例中,所述宽谱光源1为紫外至红外波段的宽谱光源,从而能够实现多种气体吸收线发覆盖,提高激光雷达的气体探测能力。In one embodiment, the broad-spectrum light source 1 is a broad-spectrum light source in the ultraviolet to infrared wavelength band, so as to realize the coverage of various gas absorption lines and improve the gas detection capability of the lidar.

在一个实施例中,所述宽谱光源1为ASE自发辐射光源或白光光源。其中,ASE自发辐射光源具有成本低,覆盖光谱范围宽的优点。In one embodiment, the broad-spectrum light source 1 is an ASE spontaneous emission light source or a white light source. Among them, the ASE spontaneous emission light source has the advantages of low cost and wide spectral coverage.

宽谱光源选择在光纤中损耗小的1μm~2μm波段的激光,优选为1.5μm波段。此波段对人眼安全,同时传输损耗小。The broad-spectrum light source selects laser light in the wavelength range of 1 μm to 2 μm with low loss in the optical fiber, preferably in the 1.5 μm wavelength band. This band is eye-safe and has low transmission loss.

所述多通道滤波器2用于将宽谱光源滤出多个不同频率的激光信号,多个不同频率分别对应待测气体吸收曲线的不同位置;其中,滤出的每个频率对应的曲线的半高全宽均小于预设的阈值。待测气体包含一种或多种气体。The multi-channel filter 2 is used to filter out a plurality of laser signals of different frequencies from the broad-spectrum light source, and the plurality of different frequencies correspond to different positions of the absorption curve of the gas to be measured; The full width at half maximum is smaller than the preset threshold. The gas to be measured contains one or more gases.

进一步的,所述多通道滤波Further, the multi-channel filtering

器为法布里珀罗干涉仪;所述预设的阈值为100MHz。由于本发明需要通过一个气体吸收曲线同时测量多种气体,滤出的每个频率对应的待测气体吸收曲线的半高全宽过大会导致无法区分两种气体。本发明的发明人经过研究发现,当阈值为100MHz时,能够通过待测气体吸收曲线区分不同的气体成分。The device is a Fabry-Perot interferometer; the preset threshold is 100MHz. Since the present invention needs to measure multiple gases simultaneously through one gas absorption curve, if the full width at half maximum of the measured gas absorption curve corresponding to each filtered frequency is too large, the two gases cannot be distinguished. The inventor of the present invention has found through research that when the threshold value is 100 MHz, different gas components can be distinguished by the absorption curve of the gas to be measured.

法布里珀罗干涉仪(英文:Fabry–Pérot interferometer,简称FPI),是一种由两块平行的玻璃板组成的多光束干涉仪。其中两块玻璃板相对的内表面都具有高反射率。The Fabry–Pérot interferometer (FPI) is a multi-beam interferometer composed of two parallel glass plates. The opposing inner surfaces of two of the glass sheets are highly reflective.

对于法布里-珀罗标准具而言,其透射率随波长的显著变化是由于两块反射板之间多重反射光的干涉。当透射光为同相时它们有相长干涉,对应着标准具透射率的峰值;而当透射光反相时则对应着透射率的极小值。多重反射光彼此是否同相,取决于入射光的频率、光线在标准具内传播的折射角、标准具的厚度及其所用材料的折射率。For the Fabry-Perot etalon, the significant change in transmittance with wavelength is due to the interference of multiple reflected light between the two reflectors. When the transmitted light is in phase, they interfere constructively, corresponding to the peak of the etalon transmittance; when the transmitted light is out of phase, it corresponds to the minimum value of the transmittance. Whether multiple reflections are in phase with each other depends on the frequency of the incident light, the angle of refraction of the light propagating within the etalon, the thickness of the etalon and the refractive index of the material used.

法布里-珀罗标准具中,两束相邻的反射光之间的光程差

Figure DEST_PATH_IMAGE001
,在不考虑相移时的相位差为The optical path difference between two adjacent reflected beams in the Fabry-Perot etalon
Figure DEST_PATH_IMAGE001
, the phase difference without considering the phase shift is

Figure DEST_PATH_IMAGE002
Figure DEST_PATH_IMAGE002

其中,n为标准间腔内的折射率;l为标准具的腔长,

Figure DEST_PATH_IMAGE003
为入射光中心波长;
Figure DEST_PATH_IMAGE004
为入射角;Among them, n is the refractive index in the standard cavity; l is the cavity length of the etalon,
Figure DEST_PATH_IMAGE003
is the central wavelength of the incident light;
Figure DEST_PATH_IMAGE004
is the angle of incidence;

另外,内界面反射率都为R,则标准具的透射率函数Te由下式给出In addition, the reflectivity of the internal interface is R, the transmittance function Te of the etalon is given by the following formula

Figure DEST_PATH_IMAGE005
Figure DEST_PATH_IMAGE005

Figure DEST_PATH_IMAGE006
Figure DEST_PATH_IMAGE006

当相邻两束光之间的光程差为波长的整数倍时,透射率函数有最大值1。在介质无吸光的情形下,标准具的反射率Re满足When the optical path difference between two adjacent beams of light is an integer multiple of the wavelength, the transmittance function has a maximum value of 1. In the case where the medium does not absorb light, the reflectivity Re of the etalon satisfies

Figure DEST_PATH_IMAGE007
Figure DEST_PATH_IMAGE007

Figure DEST_PATH_IMAGE008
,也就是光程差为波长的半奇数倍时透射率函数有最小值,此时对应着反射率的最大值Rmax when
Figure DEST_PATH_IMAGE008
, that is, when the optical path difference is a half-odd multiple of the wavelength, the transmittance function has a minimum value, which corresponds to the maximum value R max of the reflectivity.

Figure DEST_PATH_IMAGE009
Figure DEST_PATH_IMAGE009

在透射率函数上,两个相邻的透射峰值之间的波长间隔被称作标准具的自由光谱间距(FSR),它由下式给出:As a function of transmittance, the wavelength separation between two adjacent transmission peaks is called the free spectral distance (FSR) of the etalon and is given by:

Figure DEST_PATH_IMAGE010
Figure DEST_PATH_IMAGE010

其中,

Figure DEST_PATH_IMAGE011
表示标准具的自由光谱间距,
Figure DEST_PATH_IMAGE012
是最近峰值的中心波长。in,
Figure DEST_PATH_IMAGE011
represents the free spectral spacing of the etalon,
Figure DEST_PATH_IMAGE012
is the center wavelength of the nearest peak.

由于本发明需要在一个吸收线上同时测量多种气体,因此对多通道滤波器的自由谱间距有特殊的要求,自由谱间距需要小于6.25GHz,透过率曲线的半高全宽需要小于100MHz,半高全宽过大将无法用于气体吸收线的探测。Since the invention needs to measure multiple gases simultaneously on one absorption line, there are special requirements for the free spectral spacing of the multi-channel filter. The free spectral spacing needs to be less than 6.25 GHz, the full width at half maximum of the transmittance curve needs to be less than 100 MHz, If the height and full width are too large, it cannot be used for the detection of gas absorption lines.

FPI能够产生自由谱间距6.25GHz并且半高全宽小于100MHz的透过率曲线,进一步完成对宽谱光谱的多通道滤波,产生多个频率的光束用于宽谱的气体探测。FPI can generate a transmittance curve with a free spectral spacing of 6.25GHz and a full width at half maximum less than 100MHz, further completes the multi-channel filtering of the broad-spectrum spectrum, and generates beams of multiple frequencies for broad-spectrum gas detection.

因此,所述多通道滤波器为法布里珀罗干涉仪;所述预设的阈值为100MHz。Therefore, the multi-channel filter is a Fabry-Perot interferometer; the preset threshold is 100 MHz.

所述脉冲发生和功率放大模块用于将宽谱光源输出的连续光斩成脉冲光并通过激光放大器将脉冲光进行功率放大。The pulse generating and power amplifying module is used for chopping the continuous light output from the broad-spectrum light source into pulsed light and amplifying the power of the pulsed light through a laser amplifier.

所述脉冲发生和功率放大模块包括脉冲发生器3和功率放大器4。The pulse generation and power amplification module includes a pulse generator 3 and a power amplifier 4 .

所述脉冲发生器3用于将宽谱光源斩成脉冲光。脉冲发生器为电光调制器EOM、声光调制器AOM等。The pulse generator 3 is used to chop the broad-spectrum light source into pulsed light. The pulse generators are electro-optical modulator EOM, acousto-optical modulator AOM and so on.

所述功率放大器4用于脉冲光进行功率放大;功率放大器优选为光纤激光放大器,例如掺铒光纤放大器EDFA等。The power amplifier 4 is used for power amplification of pulsed light; the power amplifier is preferably a fiber laser amplifier, such as an erbium-doped fiber amplifier EDFA and the like.

所述激光束收发模块20用于出射放大后的激光脉冲至大气,并接收激光在大气中的后向散射信号。The laser beam transceiver module 20 is used for outputting the amplified laser pulses to the atmosphere, and receiving the backscattered signals of the laser light in the atmosphere.

所述解波分复用模块7用于将多个频率的激光后向散射信号解复用至对应的多个光纤信号通道中。不同的光纤信号通道对应不同的信号频率。The demultiplexing module 7 is used for demultiplexing the laser backscattered signals of multiple frequencies into corresponding multiple optical fiber signal channels. Different optical fiber signal channels correspond to different signal frequencies.

进一步的,所述解波分复用模块7为WDM波分复用器或色散光栅。WDM(WavelengthDivision Multiplexing) 即波分复用器。Further, the demultiplexing module 7 is a WDM wavelength division multiplexer or a dispersion grating. WDM (WavelengthDivision Multiplexing) is a wavelength division multiplexer.

所述多通道探测模块8包括多个探测通道,用于探测解复用后的多个光纤信号通道中的回波信号,输出相应的电信号;不同频率的回波信号由不同的探测通道获得。The multi-channel detection module 8 includes a plurality of detection channels, which are used to detect the echo signals in the multiple optical fiber signal channels after demultiplexing, and output corresponding electrical signals; the echo signals of different frequencies are obtained by different detection channels .

解波分复用模块7的输入端与激光束收发模块20的输出端连接,解波分复用模块7的输出端包括多个光纤通道,解波分复用模块7的多个光纤通道分别与多个探测通道对应连接。The input end of the demultiplexing module 7 is connected to the output end of the laser beam transceiver module 20. The output end of the demultiplexing module 7 includes a plurality of optical fiber channels, and the plurality of optical fiber channels of the demultiplexing module 7 are respectively Correspondingly connected with multiple detection channels.

在一个实施例中,所述解波分复用模块包括多个输出端,所述多通道探测模块包括对应的多个探测通道,每个探测通道用于探测对应的一个解波分复用模块输出端输出的信号。In one embodiment, the de-wavelength division multiplexing module includes a plurality of output terminals, the multi-channel detection module includes a plurality of corresponding detection channels, and each detection channel is used for detecting a corresponding de-wavelength division multiplexing module output signal.

所述多通道探测模块包括与宽谱光源输出波段对应的多通道光电探测器。这样,只需要一个多通道探测器即可实现多通道的探测,简化系统结构,节约系统成本和体积。The multi-channel detection module includes a multi-channel photodetector corresponding to the output band of the broad-spectrum light source. In this way, only one multi-channel detector is needed to realize multi-channel detection, the system structure is simplified, and the system cost and volume are saved.

在另一个实施例中,所述多通道探测模块包括多个光电探测器。In another embodiment, the multi-channel detection module includes a plurality of photodetectors.

光电探测器为光电倍增管、硅探测器、铟镓砷探测器或碲镉汞探测器。The photodetectors are photomultiplier tubes, silicon detectors, indium gallium arsenide detectors or mercury cadmium telluride detectors.

所述数据采集模块9用于采集所述多通道探测模块8输出的电信号。The data collection module 9 is used to collect the electrical signals output by the multi-channel detection module 8 .

所述数据处理模块10用于处理多个频率的回波信号,反演待测气体在不同距离处的吸收光谱,计算不同距离处的气体浓度。The data processing module 10 is used for processing echo signals of multiple frequencies, inverting absorption spectra of the gas to be measured at different distances, and calculating gas concentrations at different distances.

进一步的,所述数据处理模块采用洛伦兹曲线拟合算法进行待测气体浓度反演,对多通道回波信号进行洛伦兹曲线拟合获得待测气体吸收曲线的面积,根据所述面积计算待测气体的浓度,采用本发明的算法,能够简单快捷地获得更高的气体探测精度。Further, the data processing module uses the Lorentz curve fitting algorithm to invert the concentration of the gas to be measured, and performs Lorentz curve fitting on the multi-channel echo signal to obtain the area of the absorption curve of the gas to be measured. To calculate the concentration of the gas to be detected, by using the algorithm of the present invention, higher gas detection accuracy can be obtained simply and quickly.

进一步的,所述激光束收发模块20包括环形器5和望远镜6,所述环形器5用于出射所述放大后的激光脉冲至所述望远镜,还用于将所述望远镜6接收回的大气后向散射信号传输至所述解波分复用模块7;所述望远镜6用于出射激光束至大气中和接收大气后向散射信号。Further, the laser beam transceiver module 20 includes a circulator 5 and a telescope 6, and the circulator 5 is used to emit the amplified laser pulses to the telescope, and is also used to receive the atmosphere returned by the telescope 6. The backscattered signal is transmitted to the demultiplexing module 7; the telescope 6 is used to emit the laser beam into the atmosphere and receive the atmospheric backscattered signal.

基于本发明上述全部实施例,下面对其具体的工作原理进行阐述说明。Based on all the above embodiments of the present invention, the specific working principle thereof will be described below.

参考图2,图2为本发明实施例提供的某一位置的宽谱光源光谱图。Referring to FIG. 2 , FIG. 2 is a spectrum diagram of a broad-spectrum light source at a certain position provided by an embodiment of the present invention.

如图2所示,其相对应图1中的a点,位于宽谱光源1和多通道滤波器2之间,图2示意了宽谱光源1出射的宽谱光源的光谱。As shown in FIG. 2 , it corresponds to point a in FIG. 1 and is located between the broad-spectrum light source 1 and the multi-channel filter 2 . FIG. 2 illustrates the spectrum of the broad-spectrum light source emitted by the broad-spectrum light source 1 .

参考图3,为本发明实施例提供的某一位置的光源经多通道滤波器后的光谱图。Referring to FIG. 3 , it is a spectrogram of a light source at a certain position provided by an embodiment of the present invention after being subjected to a multi-channel filter.

如图3所示,其相对应图1中的b点,位于多通道滤波器2和脉冲发生模块3之间,图3示意了经多通道滤波器滤波后宽谱光源光谱,这里举例自由谱间距为6.25 GHz的法布里珀罗干涉仪作为多通道滤波器,λ1、λ2、λ3、λ4、λ5、λ6和λ7分别为各个通道滤波的中心波长。As shown in Figure 3, it corresponds to point b in Figure 1 and is located between the multi-channel filter 2 and the pulse generation module 3. Figure 3 shows the spectrum of the broad-spectrum light source after filtering by the multi-channel filter. Here is an example of a free spectrum A Fabry-Perot interferometer with a spacing of 6.25 GHz is used as a multi-channel filter, and λ1, λ2, λ3, λ4, λ5, λ6 and λ7 are the central wavelengths of each channel filter, respectively.

参考图4,图4为本发明实施例提供的某一位置的大气气体吸收线。Referring to FIG. 4 , FIG. 4 is an atmospheric gas absorption line at a certain position according to an embodiment of the present invention.

如图4所示,其相对应图1中的c点,位于激光束收发模块20后的大气中,图4示意了待测气体的吸收谱线。As shown in FIG. 4 , it corresponds to point c in FIG. 1 and is located in the atmosphere behind the laser beam transceiver module 20 . FIG. 4 illustrates the absorption spectrum of the gas to be measured.

参考图5,图5为本发明实施例提供的不同波长的雷达回波信号。Referring to FIG. 5 , FIG. 5 is a radar echo signal of different wavelengths provided by an embodiment of the present invention.

如图5所示,其相对应图1中的d点,位于环形器5和解波分复用模块7之间,多通道滤波器2滤除了7个通道,这里展示其中两个中心波长为λ1和λ4的通道的回波信号。As shown in Figure 5, which corresponds to point d in Figure 1, it is located between the circulator 5 and the demultiplexing module 7, and the multi-channel filter 2 has filtered out 7 channels, and here it is shown that two of the central wavelengths are λ1 and the echo signal of the channel of λ4.

参考图6,图6为本发明实施例提供的解波分复用器各通道的透过率曲线。Referring to FIG. 6, FIG. 6 is a transmittance curve of each channel of a demultiplexer provided by an embodiment of the present invention.

如图6所示,其相对应图1中的e点,位于解波分复用模块7中,解波分复用模块各通道的中心波长和通道间隔与多通道滤波器对应,中心波长位置分别为λ1、λ2、λ3、λ4、λ5、λ6和λ7,解复用模块10分别将各个波长的回波信号解复用至多个光纤中,解复用后的多通道回波信号被多通道探测模块8接收,探测模块输出的电信号输送至数据采集模块9采集。As shown in Figure 6, it corresponds to point e in Figure 1, and is located in the demultiplexing module 7. The central wavelength and channel interval of each channel of the demultiplexing module correspond to the multi-channel filter, and the position of the central wavelength They are λ1, λ2, λ3, λ4, λ5, λ6 and λ7 respectively. The demultiplexing module 10 demultiplexes the echo signals of each wavelength into multiple fibers, and the demultiplexed multi-channel echo signals are multi-channel. The detection module 8 receives, and the electrical signal output by the detection module is sent to the data acquisition module 9 for collection.

参考图7,图7为本发明实施例提供的某一位置的数据处理后的多波长探测的待测气体吸收强度,以及非线性拟合的气体吸收光谱。Referring to FIG. 7 , FIG. 7 shows the multi-wavelength detection of the gas absorption intensity to be detected after data processing at a certain position, and the gas absorption spectrum of nonlinear fitting according to an embodiment of the present invention.

如图7所示,其相对应图1中的f点,位于数据处理模块10中,在获得各个通道的回波信号后,数据处理模块10处理得到每个距离处的多个波长的吸收系数,其中一个距离处的7个波长的吸收系数如图7中圆圈所示。进一步地,通过对获得的多波长吸收系数进行非线性拟合,得到该距离处的待测气体吸收谱线,最后得到同时具有光谱分辨率、时间和空间分辨率的待测气体吸收特征。As shown in FIG. 7 , it corresponds to point f in FIG. 1 and is located in the data processing module 10. After obtaining the echo signals of each channel, the data processing module 10 processes and obtains the absorption coefficients of multiple wavelengths at each distance. , the absorption coefficients of 7 wavelengths at one distance are shown as circles in Figure 7. Further, by nonlinear fitting of the obtained multi-wavelength absorption coefficients, the absorption spectral line of the gas to be measured at the distance is obtained, and finally the absorption characteristics of the gas to be measured with spectral resolution, temporal resolution and spatial resolution are obtained.

进一步的,所述数据处理模块采用洛伦兹曲线拟合算法进行待测气体浓度反演,对多通道回波信号进行洛伦兹曲线拟合获得待测气体吸收曲线的面积,根据所述面积计算待测气体的浓度。Further, the data processing module uses the Lorentz curve fitting algorithm to invert the concentration of the gas to be measured, and performs Lorentz curve fitting on the multi-channel echo signal to obtain the area of the absorption curve of the gas to be measured. Calculate the concentration of the gas to be measured.

具体的,所述数据处理模块包括非线性拟合单元和气体浓度计算单元;Specifically, the data processing module includes a nonlinear fitting unit and a gas concentration calculation unit;

所述非线性拟合单元用于根据所述数据采集模块采集到的多个频率的回波信号得到不同距离处的吸收光谱,并对所述吸收光谱进行非线性拟合,获得拟合曲线;The nonlinear fitting unit is configured to obtain absorption spectra at different distances according to the echo signals of multiple frequencies collected by the data acquisition module, and perform nonlinear fitting on the absorption spectra to obtain a fitting curve;

所述气体浓度计算单元用于计算所述拟合曲线的面积,根据所述面积计算待测气体的浓度。The gas concentration calculation unit is configured to calculate the area of the fitting curve, and calculate the concentration of the gas to be measured according to the area.

具体的,由于待测气体的浓度由分压P确定,而分压满足下式:Specifically, since the concentration of the gas to be measured is determined by the partial pressure P, and the partial pressure satisfies the following formula:

Figure DEST_PATH_IMAGE013
Figure DEST_PATH_IMAGE013

其中,A是吸收系数的洛伦兹线型面积,P为待测气体的分压,T为待测气体所处的温度,T0 = 273.15 K ,P0 = 100 kPa,nL为待测气体在T0和P0时的谱线强度。通过对测量的吸收系数进行洛伦兹线型拟合,可以获得面积A,进一步可以计算分压P,从而得到待测气体的浓度。Among them, A is the Lorentz line area of the absorption coefficient, P is the partial pressure of the gas to be measured, T is the temperature of the gas to be measured, T0 = 273.15 K, P0 = 100 kPa, n L is the temperature of the gas to be measured at Line intensities at T0 and P0. By performing Lorentzian line fitting on the measured absorption coefficient, the area A can be obtained, and the partial pressure P can be further calculated to obtain the concentration of the gas to be measured.

本发明中,非线性拟合优选洛伦兹曲线拟合。In the present invention, the nonlinear fitting is preferably Lorentzian curve fitting.

进一步的,对所述吸收光谱进行非线性拟合,包括:Further, performing nonlinear fitting on the absorption spectrum, including:

对所述吸收光谱采用洛伦兹曲线拟合;applying Lorentzian curve fitting to the absorption spectrum;

若吸收光谱中包含一个吸收峰,则对所述吸收光谱采用单峰洛伦兹曲线拟合;If the absorption spectrum contains one absorption peak, then fitting the absorption spectrum with a single-peak Lorentzian curve;

若吸收光谱中包含多个吸收峰,则对所述吸收光谱采用多峰洛伦兹曲线拟合。If the absorption spectrum contains multiple absorption peaks, a multi-peak Lorentzian curve fitting is used for the absorption spectrum.

多个吸收峰对应待测气体中的一种或多种气体;若吸收光谱中包含N个气体吸收峰,则对吸收光谱进行N峰拟合,分别得到每个吸收峰对应的气体的拟合曲线。再根据每种气体的拟合曲线计算每种气体的浓度。The multiple absorption peaks correspond to one or more gases in the gas to be measured; if the absorption spectrum contains N gas absorption peaks, the N peaks are fitted to the absorption spectrum, and the fitting of the gas corresponding to each absorption peak is obtained respectively. curve. Then calculate the concentration of each gas according to the fitted curve of each gas.

图7为待测气体仅包含一种气体时,则对不同距离处的吸收光谱采用单峰洛伦兹曲线拟合后的拟合曲线。FIG. 7 is a fitting curve obtained by fitting a single-peak Lorentzian curve to the absorption spectra at different distances when the gas to be tested contains only one gas.

图8为待测气体包含两种气体时,测量得到的不同距离处的吸收光谱。FIG. 8 shows absorption spectra obtained by measurement at different distances when the gas to be measured contains two gases.

图9为待测气体包含两种气体时,则对不同距离处的吸收光谱采用双峰洛伦兹曲线拟合后的拟合曲线。在计算气体浓度时,对两条拟合曲线分别计算,就能得到两种气体的浓度。FIG. 9 is a fitting curve obtained by using a bimodal Lorentzian curve to fit the absorption spectra at different distances when the gas to be tested contains two gases. When calculating the gas concentration, the two fitted curves are calculated separately to obtain the concentration of the two gases.

综上所述,本发明提供的基于宽谱光源的气体探测激光雷达,本发明通过采用宽谱光源,克服了采用传统激光雷达由于要求窄线宽光源造成的受激布里渊散射效应强,进而对激光器的输出功率的限制,因此宽谱光源可以实现显著提高激光雷达的功率和信噪比。本发明采用宽谱光源配合多通道滤波模块,不需要配置多个光源,成本低,覆盖光谱范围宽,可同时探测多种气体。To sum up, the gas detection lidar based on the broad-spectrum light source provided by the present invention overcomes the strong stimulated Brillouin scattering effect caused by the use of the traditional lidar due to the requirement of a narrow-linewidth light source by using a broad-spectrum light source, In turn, the output power of the laser is limited, so the broad-spectrum light source can significantly improve the power and signal-to-noise ratio of the lidar. The invention adopts a broad-spectrum light source and a multi-channel filter module, does not need to configure multiple light sources, has low cost, covers a wide spectrum range, and can detect multiple gases at the same time.

本发明通过采用多通道滤波器滤出多个不同频率的激光进行探测,由于多个不同的频率成分分别位于待测吸收线的不同位置,能够实现多种成分的气体光谱同时探测,采用本发明的方法,只需要一次测量,不需要对光谱进行扫描,不需要实时的激光波长锁定和校准,大大简化了多气体成分同时探测系统的复杂度,测量速度快,耗时少,可以做到准实时测量,显著提高了时间分辨率。The invention uses a multi-channel filter to filter out a plurality of lasers with different frequencies for detection. Since a plurality of different frequency components are located at different positions of the absorption line to be measured, simultaneous detection of gas spectra of various components can be realized. This method requires only one measurement, does not need to scan the spectrum, and does not require real-time laser wavelength locking and calibration, which greatly simplifies the complexity of the simultaneous detection system for multiple gas components. The measurement speed is fast, time-consuming, and accurate Real-time measurement with significantly improved temporal resolution.

本发明的解波分复用器将多个频率的大气回波信号传输至多通道探测器进行信号的探测,从而完成高时空分辨率的气体光谱的探测。The demultiplexer of the present invention transmits atmospheric echo signals of multiple frequencies to a multi-channel detector for signal detection, thereby completing gas spectrum detection with high temporal and spatial resolution.

相比现有激光雷达的窄线宽光源,本发明采用宽谱光源成本低,具有很大的价格优势。Compared with the narrow linewidth light source of the existing laser radar, the present invention adopts the broad spectrum light source with low cost and has a great price advantage.

本发明使用的光纤通讯器件成熟,如多通道滤波器和解波分复用器,完成宽谱的气体吸收光谱探测,相对于传统气体探测激光雷达,该雷达既能够获得光谱分辨率,又能够获得时空分辨率。The optical fiber communication devices used in the present invention are mature, such as multi-channel filters and demultiplexers, to complete the wide-spectrum gas absorption spectrum detection. Compared with the traditional gas detection laser radar, the radar can not only obtain spectral resolution, but also obtain spatiotemporal resolution.

本发明的数据处理模块采用洛伦兹曲线拟合算法进行待测气体浓度反演,对多通道回波信号进行洛伦兹曲线拟合以获得待测气体吸收曲线的面积,根据面积计算待测气体的浓度,能够获得更高的探测精度。The data processing module of the present invention uses the Lorentz curve fitting algorithm to invert the concentration of the gas to be measured, performs Lorentz curve fitting on the multi-channel echo signal to obtain the area of the absorption curve of the gas to be measured, and calculates the area of the gas to be measured according to the area. The concentration of the gas can obtain higher detection accuracy.

以上所述,仅为本发明较佳的具体实施方式,但本发明的保护范围并不局限于此,任何熟悉本技术领域的技术人员在本发明披露的技术范围内,可轻易想到的变化或替换,都应涵盖在本发明的保护范围之内。因此,本发明的保护范围应该以权利要求书的保护范围为准。The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

需要说明的是,在本文中,诸如第一和第二等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来,而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且,术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含,从而使得包括一系列要素的过程、方法、物品或者设备不仅包括那些要素,而且还包括没有明确列出的其他要素,或者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下,由语句“包括一个……”限定的要素,并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Claims (10)

1. A gas detection lidar based on a broad spectrum light source, comprising: the device comprises a wide-spectrum light source, a multi-channel filter, a pulse generation and power amplification module, a laser beam transceiving module, a wavelength division multiplexing de-multiplexing module, a multi-channel detection module, a data acquisition module and a data processing module;
the wide-spectrum light source is used for emitting wide-spectrum laser;
the multi-channel filter is used for filtering wide-spectrum laser emitted by the wide-spectrum light source into a plurality of laser signals with different frequencies, and the plurality of laser signals with different frequencies respectively correspond to different positions of an absorption curve of the gas to be detected; wherein, the full width at half maximum of the filtered curve corresponding to each frequency is smaller than a preset threshold value; the gas to be measured comprises one or more gases;
the pulse generation and power amplification module is used for chopping continuous light output by the wide-spectrum light source into pulse light and amplifying the power of the pulse light through the laser amplifier;
the laser beam transceiver module is used for emitting the amplified laser pulse to the gas to be detected and receiving a back scattering signal of the laser in the gas to be detected;
the wavelength division multiplexing module is used for demultiplexing laser backscattering signals of multiple frequencies to corresponding multiple optical fiber signal channels, and different optical fiber signal channels correspond to different signal frequencies;
the multichannel detection module comprises a plurality of detection channels and is used for detecting signals in the plurality of optical fiber signal channels demultiplexed by the wavelength division multiplexing module and outputting corresponding electric signals;
the data acquisition module is used for acquiring the electric signals output by the multi-channel detection module;
the data processing module is used for processing the echo signals of the multiple frequencies acquired by the data acquisition module, inverting the absorption spectra of the gas to be measured at different distances and calculating the gas concentrations at different distances.
2. A broad spectrum light source based gas detection lidar according to claim 1, wherein: the wide-spectrum light source is a wide-spectrum light source from ultraviolet to infrared bands.
3. A broad spectrum light source based gas detection lidar according to claim 1, wherein: the multichannel filter is a Fabry-Perot interferometer; the preset threshold is 100 MHz.
4. A broad spectrum light source based gas detection lidar according to claim 1, wherein: the laser beam transceiver module comprises a circulator and a telescope, the circulator is used for emitting the amplified laser pulse to the telescope, and the circulator is also used for transmitting a back scattering signal of the gas to be detected received and retrieved by the telescope to the wavelength division multiplexing module; the telescope is used for emitting laser beams to the gas to be measured and receiving back scattering signals of the gas to be measured.
5. A broad spectrum light source based gas detection lidar according to claim 1, wherein: the wavelength division multiplexing module is a WDM wavelength division multiplexer or a dispersion grating.
6. A broad spectrum light source based gas detection lidar according to claim 1, wherein: the wavelength division multiplexing module comprises a plurality of output ends, the multi-channel detection module comprises a plurality of corresponding detection channels, and each detection channel is used for detecting a signal output by the output end of the corresponding wavelength division multiplexing module.
7. A broad spectrum light source based gas detection lidar according to claim 6, wherein: the multichannel detection module comprises a multichannel photoelectric detector corresponding to the output waveband of the wide-spectrum light source.
8. The broad spectrum light source-based gas detection lidar of claim 6, wherein the multi-channel detection module comprises a plurality of photodetectors.
9. The broad spectrum light source based gas detection lidar of claim 1, wherein the data processing module comprises a nonlinear fitting unit and a gas concentration calculation unit;
the nonlinear fitting unit is used for obtaining absorption spectra at different distances according to the echo signals of the multiple frequencies acquired by the data acquisition module and performing nonlinear fitting on the absorption spectra to obtain a fitting curve;
and the gas concentration calculating unit is used for calculating the area of the fitting curve and calculating the concentration of the gas to be measured according to the area.
10. The broad spectrum light source based gas detection lidar of claim 1, wherein the non-linear fitting of the absorption spectrum comprises:
fitting the absorption spectrum by adopting a Lorentzian curve;
if the absorption spectrum contains an absorption peak, fitting a single-peak Lorentzian curve to the absorption spectrum;
and if a plurality of absorption peaks are contained in the absorption spectrum, fitting a multimodal Lorentzian curve to the absorption spectrum.
CN202210934522.3A 2022-08-04 2022-08-04 Gas detection laser radar based on wide-spectrum light source Active CN115015966B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210934522.3A CN115015966B (en) 2022-08-04 2022-08-04 Gas detection laser radar based on wide-spectrum light source

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210934522.3A CN115015966B (en) 2022-08-04 2022-08-04 Gas detection laser radar based on wide-spectrum light source

Publications (2)

Publication Number Publication Date
CN115015966A true CN115015966A (en) 2022-09-06
CN115015966B CN115015966B (en) 2022-10-28

Family

ID=83065979

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210934522.3A Active CN115015966B (en) 2022-08-04 2022-08-04 Gas detection laser radar based on wide-spectrum light source

Country Status (1)

Country Link
CN (1) CN115015966B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115980710A (en) * 2023-03-21 2023-04-18 南京信息工程大学 Differential absorption laser radar transmitting device based on electro-optical modulation and laser radar

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109375190A (en) * 2018-12-25 2019-02-22 中国科学院合肥物质科学研究院 Frequency comb lidar detection method and system for simultaneous measurement of various atmospheric components
CN109959944A (en) * 2019-03-29 2019-07-02 中国科学技术大学 Anemometry laser radar based on wide spectrum light source
CN110749872A (en) * 2018-07-23 2020-02-04 中国科学技术大学 A coherent differential absorption lidar and a method for detecting gas concentration
CN111208531A (en) * 2020-01-19 2020-05-29 中国科学技术大学 Single photon imaging laser radar system based on wide-spectrum light source
CN111829584A (en) * 2020-07-06 2020-10-27 山东省科学院 Continuous space synchronization monitoring device for ocean temperature and pressure
US20220026577A1 (en) * 2019-07-02 2022-01-27 University Of Science And Technology Of China Dispersion gating-based atmospheric composition measurement laser radar
CN114062273A (en) * 2021-11-18 2022-02-18 国网安徽省电力有限公司电力科学研究院 An anti-interference optical fiber photoacoustic gas sensing system and method

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110749872A (en) * 2018-07-23 2020-02-04 中国科学技术大学 A coherent differential absorption lidar and a method for detecting gas concentration
CN109375190A (en) * 2018-12-25 2019-02-22 中国科学院合肥物质科学研究院 Frequency comb lidar detection method and system for simultaneous measurement of various atmospheric components
CN109959944A (en) * 2019-03-29 2019-07-02 中国科学技术大学 Anemometry laser radar based on wide spectrum light source
US20220026577A1 (en) * 2019-07-02 2022-01-27 University Of Science And Technology Of China Dispersion gating-based atmospheric composition measurement laser radar
CN111208531A (en) * 2020-01-19 2020-05-29 中国科学技术大学 Single photon imaging laser radar system based on wide-spectrum light source
CN111829584A (en) * 2020-07-06 2020-10-27 山东省科学院 Continuous space synchronization monitoring device for ocean temperature and pressure
CN114062273A (en) * 2021-11-18 2022-02-18 国网安徽省电力有限公司电力科学研究院 An anti-interference optical fiber photoacoustic gas sensing system and method

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHONG WANG等: "Spatial resolution enhancement of coherent Doppler wind lidar using joint time–frequency analysis", 《OPTICS COMMUNICATIONS》 *
高海滨等: "频率扫描法标定法布里-拍罗腔的锁定模式", 《激光与光电子学进展》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115980710A (en) * 2023-03-21 2023-04-18 南京信息工程大学 Differential absorption laser radar transmitting device based on electro-optical modulation and laser radar

Also Published As

Publication number Publication date
CN115015966B (en) 2022-10-28

Similar Documents

Publication Publication Date Title
CN105675576B (en) A kind of laser radar system of measurement atmospheric water Raman spectrums and aerosol fluorescence Spectra
CN100529797C (en) All-fiber Raman scattering laser radar system based on wavelength-division multiplex technology for diffracting
CN100507455C (en) A Multiplexing Method for Intensity Modulated Fiber Optic Sensors
CN108663671B (en) Laser radar system based on DWDM
CN101718942A (en) Multi-channel fiber Bragg grating (FBG) demodulator
ITBG20070042A1 (en) SENSOR AND METHOD TO DETERMINE THE TEMPERATURE ALONG A FIBER OPTIC.
JP2009523248A (en) Optical signal measurement system
US9372150B2 (en) Optical method and system for measuring an environmental parameter
US6396574B1 (en) Apparatus for measuring the wavelength, optical power and optical signal-to-noise ratio of each optical signal in wavelength-division multiplexing optical communication
CN109443403B (en) Optical fiber EFPI sensor demodulating device
Wu et al. Multi-beam single-photon LiDAR with hybrid multiplexing in wavelength and time
TW200422668A (en) Fiber Bragg grating sensing system of light intensity and wave-divided multiplex
CN115015966B (en) Gas detection laser radar based on wide-spectrum light source
CN112748440A (en) Photon time broadening laser radar system based on microcavity optical comb
CN103344184B (en) Based on the wavelength-division of the mixing certainly multiplexed multi-channel displacement sensing system of linear cavity multi-wavelength optical fiber laser
RU169314U1 (en) Lidar for remote measurement of temperature and humidity
US9244002B1 (en) Optical method and system for measuring an environmental parameter
CN109557557B (en) Software-defined multifunctional laser radar
CN104697634A (en) Very high resolution spectral measurement device and method
CN105785388B (en) A kind of water Brillouin scattering and elastic scattering laser radar based on virtual image phased array
US6417926B1 (en) Wavelength measuring system
CN114414528A (en) Double-optical-fiber end-face interference salinity detection method based on 5G microwave photon signal
CN105606140B (en) Low-frequency acquisition without pumping multi-wavelength Brillouin fiber laser sensor
CN105865498B (en) Highly sensitive distributed optical fiber sensing system based on self-excitation Brillouin laser
CN117091686B (en) Distributed optical fiber vibration sensor based on frequency division multiplexing

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20230517

Address after: Building 1, Building 4, No. 5 Wangjiang Road, Nanjing Area, China (Jiangsu) Pilot Free Trade Zone, Nanjing City, Jiangsu Province, 210000, X-108

Patentee after: Jiangsu Guangzai Technology Co.,Ltd.

Address before: 210044, No. 219, Ning six road, Pukou District, Jiangsu, Nanjing

Patentee before: Nanjing University of Information Science and Technology

TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20240123

Address after: No. 2 Chongren Road, Luxia Town, Yanping District, Nanping City, Fujian Province, 353000

Patentee after: Fujian Ruicarbon Optoelectronic Precision Instrument Co.,Ltd.

Country or region after: China

Address before: Building 1, Building 4, No. 5 Wangjiang Road, Nanjing Area, China (Jiangsu) Pilot Free Trade Zone, Nanjing City, Jiangsu Province, 210000, X-108

Patentee before: Jiangsu Guangzai Technology Co.,Ltd.

Country or region before: China

TR01 Transfer of patent right