技术领域technical field
本发明涉及测风激光雷达领域，尤其涉及一种基于差分受激布里渊增益效应的直接测风激光雷达。The invention relates to the field of wind measuring laser radar, in particular to a direct wind measuring laser radar based on differential stimulated Brillouin gain effect.
背景技术Background technique
测风激光雷达对提高长期天气预报的准确性、改进气候研究模型、提高军事环境预报等有重大意义。因此，大气风场的测量受到越来越多的关注，国际民航机构、世界气象组织、世界各国航空航天的研究机构等组织都正在积极地开展风场探测系统的研究与开发。Wind lidar is of great significance to improve the accuracy of long-term weather forecasts, improve climate research models, and improve military environment forecasts. Therefore, the measurement of atmospheric wind field has received more and more attention. Organizations such as the International Civil Aviation Agency, the World Meteorological Organization, and aerospace research institutions in various countries are actively carrying out research and development of wind field detection systems.
多普勒测风激光雷达根据探测原理的不同可分为相干探测和直接探测。相干探测通过激光大气回波信号与本振激光相干的方式探测风速。直接探测则利用鉴频器将多普勒频移信息转化为能量的相对变化以探测大气风速。直接探测可分为条纹技术和边缘技术。在基于边缘技术的直接探测测风激光雷达中，F-P干涉仪具有陡峭的边缘，高的速度灵敏度，针对不同探测目标和工作波长可优化设定等优点，是直接探测测风激光雷达中应用最广泛的鉴频器。国外开展基于F-P干涉仪的多普勒直接探测测风激光雷达的研究单位包括法国国家科学研究中心(Centre national de la recherche scientifique，CNRS)，美国国家航空航天局(National Aeronautics and Space Administration，NASA)，欧洲航天局(European Space Agency，ESA)，北极激光雷达中层大气研究观测站(The Arctic LidarObservatory for Middle Atmosphere Research，ALOMAR)，法国OHP观测站(Observatoirede Haute-Provence，OHP)，美国国家大气研究中心(National Center for AtmosphericResearch,NCAR)和密西根航空航天公司(Michigan Aerospace Corporation，MAC)等。国内方面如中国科学技术大学，中国海洋大学，安徽光学精密机械研究所及哈尔滨工业大学等科研单位也报道过基于边缘鉴频技术的测风激光雷达。Doppler wind lidar can be divided into coherent detection and direct detection according to different detection principles. Coherent detection detects wind speed through the coherence of laser atmospheric echo signal and local oscillator laser. Direct detection uses a frequency discriminator to convert Doppler frequency shift information into relative changes in energy to detect atmospheric wind speed. Direct detection can be divided into stripe technology and edge technology. In the direct detection wind lidar based on edge technology, the F-P interferometer has the advantages of steep edge, high speed sensitivity, and can be optimized for different detection targets and working wavelengths. It is the most widely used in direct detection wind lidar. Extensive discriminator. Foreign research institutes that carry out Doppler direct detection wind lidar based on F-P interferometer include the French National Center for Scientific Research (Centre national de la recherche scientifique, CNRS), the US National Aeronautics and Space Administration (National Aeronautics and Space Administration, NASA) , European Space Agency (European Space Agency, ESA), Arctic Lidar Observatory for Middle Atmospheric Research Observatory (The Arctic Lidar Observatory for Middle Atmosphere Research, ALOMAR), French OHP Observatory (Observatoirede Haute-Provence, OHP), US National Center for Atmospheric Research (National Center for Atmospheric Research, NCAR) and Michigan Aerospace Corporation (Michigan Aerospace Corporation, MAC), etc. Domestic research institutions such as University of Science and Technology of China, Ocean University of China, Anhui Institute of Optics and Fine Mechanics, and Harbin Institute of Technology have also reported wind lidar based on edge frequency discrimination technology.
在直接探测测风激光雷达系统中，无法避免激光器的频率抖动，鉴频器的漂移所引入的系统误差。因此，将激光器频率锁定在鉴频器上是一项极具挑战性的工作。例如，中国科学技术大学报道了一种基于三个鉴频通道的直接探测测风激光雷达，其中两个鉴频通道形成双边缘以检测大气回波信号的多普勒频移，而第三个鉴频通道用于将激光频率实时锁定在F-P干涉仪上。然而，上述方案将增大系统的测量误差。In the direct detection wind lidar system, the frequency jitter of the laser and the system error introduced by the drift of the frequency discriminator cannot be avoided. Therefore, locking the laser frequency to the discriminator is a very challenging task. For example, the University of Science and Technology of China reported a direct detection wind lidar based on three frequency discrimination channels, two of which form a double edge to detect the Doppler frequency shift of the atmospheric echo signal, and the third The frequency discrimination channel is used to lock the laser frequency on the F-P interferometer in real time. However, the above solution will increase the measurement error of the system.
发明内容Contents of the invention
本发明的目的是提供一种基于差分受激布里渊增益效应的直接测风激光雷达，无需进行频率锁定，从而减小了系统所产生的误差；并具有较高时空分辨率，且成本相对较低。The purpose of the present invention is to provide a direct wind-measuring lidar based on the differential stimulated Brillouin gain effect, which does not need frequency locking, thereby reducing the error generated by the system; and has higher temporal and spatial resolution, and the cost is relatively lower.
本发明的目的是通过以下技术方案实现的：The purpose of the present invention is achieved through the following technical solutions:
一种基于差分受激布里渊增益效应的直接测风激光雷达，包括：连续光激光器1、相位/强度调制器2、微波信号发生器3、第一光纤环形器4、电光强度调制器5、第一掺铒光纤放大器6、望远镜发射端7、第一光纤布拉格光栅8、第二光纤布拉格光栅9、第二光纤环形器10、望远镜接收端11、第二掺铒光纤放大器12、隔离器13、第三光纤环形器14、分束器15、受激布里渊散射光纤16、第四光纤环形器17、第三光纤布拉格光栅18、第一探测器19、第二探测器20、第一采集卡21、第二采集卡22与计算机23；其中：A direct wind-measuring lidar based on the differential stimulated Brillouin gain effect, comprising: a continuous light laser 1, a phase/intensity modulator 2, a microwave signal generator 3, a first optical fiber circulator 4, and an electro-optic intensity modulator 5 , the first erbium-doped fiber amplifier 6, the telescope transmitting end 7, the first fiber Bragg grating 8, the second fiber Bragg grating 9, the second fiber circulator 10, the telescope receiving end 11, the second erbium-doped fiber amplifier 12, an isolator 13. The third fiber circulator 14, the beam splitter 15, the stimulated Brillouin scattering fiber 16, the fourth fiber circulator 17, the third fiber Bragg grating 18, the first detector 19, the second detector 20, the first A capture card 21, a second capture card 22 and a computer 23; wherein:
连续光激光器1输出的激光载波信号经过相位/强度调制器2进行相位/强度调制后，产生两个在频域上对称的频率边带，激光载波信号和两频率边带信号入射至第一光纤环形器4的A端口，其中相位/强度调制器2的控制信号由微波信号发生器3提供；入射至第一光纤环形器4A端口的光先经由B端口到达第一光纤布拉格光栅8，其中激光载波信号被第一光纤布拉格光栅8反射并经过第一光纤环形器4的B端口由C端口出射至电光强度调制器5，电光强度调制器5将反射的激光载波信号调制成脉冲光后由第一掺铒光纤放大器6放大，放大后的脉冲光由望远镜发射端7发射至大气当中；The laser carrier signal output by the continuous light laser 1 is phase/intensity modulated by the phase/intensity modulator 2 to generate two symmetrical frequency sidebands in the frequency domain, and the laser carrier signal and the two frequency sideband signals are incident on the first optical fiber A port of circulator 4, wherein the control signal of phase/intensity modulator 2 is provided by microwave signal generator 3; The carrier signal is reflected by the first fiber Bragg grating 8 and passes through the B port of the first fiber circulator 4, and then exits from the C port to the electro-optic intensity modulator 5, and the electro-optical intensity modulator 5 modulates the reflected laser carrier signal into pulsed light and then is transmitted by the first An erbium-doped fiber amplifier 6 amplifies, and the amplified pulsed light is emitted into the atmosphere by the telescope transmitting end 7;
两频率边带信号透过所述第一光纤布拉格光栅8，该信号通过第二掺铒光纤放大器12放大后经过隔离器13入射至第三光纤环形器14的A端口，透过的频率边带信号作为双频泵浦光经过第三光纤环形器14的B端口入射至受激布里渊散射光纤16的A端并由B端出射；The two-frequency sideband signal passes through the first fiber Bragg grating 8, and after the signal is amplified by the second erbium-doped fiber amplifier 12, it enters the A port of the third optical fiber circulator 14 through the isolator 13, and the transmitted frequency sideband The signal, as dual-frequency pumping light, is incident on the A-end of the stimulated Brillouin scattering fiber 16 through the B-port of the third optical fiber circulator 14 and emerges from the B-end;
由望远镜接收端11接收出射的脉冲光与大气相互作用产生的后向散射信号，该后向散射信号由望远镜接收端11入射至第二光纤环形器10的A端口，经过第二光纤环形器10的B端口入射至第二光纤布拉格光栅9，光纤布拉格光栅9将噪声信号去除后，将大气后向散射信号反射并由第二光纤环形器10的C端口出射，经过分束器15分为两路光，其中一路光经分束器15的A端口入射至受激布里渊散射光纤16的B端，进入受激布里渊散射光纤16后与频率边带信号所构成的双频泵浦光反向传输，产生受激布里渊散射，与双频泵浦光反向传输的信号光由第三光纤环形器14的B端口经C端口入射至第四光纤环形器17的A端口，并经过B端口入射至第三光纤布拉格光栅18对信号进行滤波，由第三光纤布拉格光栅18反射的信号经过第四光纤环形器17的B端口由C端口出射至第一探测器19，第一探测器19与第一采集卡21连接，由第一采集卡21将采集到的数据传输至计算机23；The backscattering signal generated by the interaction of the outgoing pulsed light and the atmosphere is received by the receiving end 11 of the telescope. The backscattering signal is incident on the A port of the second optical fiber circulator 10 by the receiving end 11 of the telescope, and passes through the second optical fiber circulator 10 The B port of the second fiber Bragg grating is incident to the second fiber Bragg grating 9. After the fiber Bragg grating 9 removes the noise signal, the atmospheric backscattering signal is reflected and emitted from the C port of the second fiber circulator 10, and is divided into two by the beam splitter 15. One path of light, wherein one path of light enters the B end of the stimulated Brillouin scattering fiber 16 through the A port of the beam splitter 15, enters the stimulated Brillouin scattering fiber 16 and forms a dual-frequency pump with frequency sideband signals The light is reversely transmitted to generate stimulated Brillouin scattering, and the signal light transmitted in reverse with the dual-frequency pump light is incident on the A port of the fourth optical fiber circulator 17 through the B port of the third optical fiber circulator 14 through the C port, And through the B port incident to the third fiber Bragg grating 18 to filter the signal, the signal reflected by the third fiber Bragg grating 18 passes through the B port of the fourth fiber circulator 17 and exits to the first detector 19 from the C port, the first The detector 19 is connected with the first acquisition card 21, and the data collected by the first acquisition card 21 is transmitted to the computer 23;
由光分束器15产生的另一路光经过光分束器15的B端口与第二探测器20连接进行能量检测，第二探测器20与第二采集卡22连接，由第二采集卡22将采集到的数据传输至计算机23，由计算机23根据第一采集卡21与第二采集卡22传输的数据进行反演计算。Another road light produced by the optical beam splitter 15 is connected to the second detector 20 through the B port of the optical beam splitter 15 for energy detection, and the second detector 20 is connected to the second acquisition card 22, and the second acquisition card 22 The collected data is transmitted to the computer 23, and the computer 23 performs inversion calculation according to the data transmitted by the first acquisition card 21 and the second acquisition card 22.
所述受激布里渊光纤16包括：The stimulated Brillouin fiber 16 includes:
单模光纤、保偏光纤、光子晶体光纤、单偏振光纤、塑料光纤或辐射光纤。Single mode fiber, polarization maintaining fiber, photonic crystal fiber, single polarization fiber, plastic fiber or radiating fiber.
所述受激布里渊光纤16利用受激布里渊散射产生透过率函数，作为鉴频器件，其工作过程如下：The stimulated Brillouin fiber 16 utilizes stimulated Brillouin scattering to generate a transmittance function, and as a frequency discrimination device, its working process is as follows:
当所述连续光激光器1出射的激光经相位/强度调制器2调制后，其频域上两个频率边带的光透过第一光纤布拉格光栅8，经第二掺铒光纤放大器12放大后进入光纤16作为双频泵浦光；由望远镜接收端11接收的后向散射信号反向入射到受激布里渊光纤16中，并在受激布里渊光纤16中发生受激布里渊散射，在频域上形成信号强度透过率函数；When the laser emitted by the continuous light laser 1 is modulated by the phase/intensity modulator 2, the light of the two frequency sidebands in the frequency domain passes through the first fiber Bragg grating 8 and is amplified by the second erbium-doped fiber amplifier 12 Enter the optical fiber 16 as a dual-frequency pump light; the backscattered signal received by the telescope receiving end 11 is incident back into the stimulated Brillouin optical fiber 16, and stimulated Brillouin optical fiber 16 generates a stimulated Brillouin Scattering, forming a signal strength transmittance function in the frequency domain;
受激布里渊光纤16作为鉴频器件将望远镜接收端11接收到的后向散射信号中所携带的频率变化转化为在鉴频器所产生的陡峭边缘透过的信号强度或功率变化，并通过第二探测器20进行能量检测。The stimulated Brillouin fiber 16 is used as a frequency discriminator to convert the frequency change carried in the backscattered signal received by the telescope receiving end 11 into a signal intensity or power change transmitted through the steep edge generated by the frequency discriminator, and Energy detection is carried out by means of the second detector 20 .
所述第一光纤布拉格光栅8、第二光纤布拉格光栅9与第三光纤布拉格光栅18均为均匀光纤布拉格光栅。The first Fiber Bragg Grating 8 , the second Fiber Bragg Grating 9 and the third Fiber Bragg Grating 18 are uniform Fiber Bragg Gratings.
在本发明所提供的技术方案中，利用受激布里渊散射构建鉴频系统，简单、易控，适用于各个波段的激光雷达，且由于出射激光频率在频谱始终位于吸收峰与增益峰之间距离的中点位置，因此不需要进行频率锁定，减小了系统所产生的误差。其具有探测精度高、成本较低、结构紧凑等优点。In the technical solution provided by the present invention, the frequency discrimination system is constructed by using stimulated Brillouin scattering, which is simple and easy to control, and is suitable for laser radars in various bands, and because the outgoing laser frequency is always between the absorption peak and the gain peak in the spectrum The midpoint of the distance, so frequency locking is not required, which reduces the error generated by the system. It has the advantages of high detection accuracy, low cost and compact structure.
附图说明Description of drawings
为了更清楚地说明本发明实施例的技术方案，下面将对实施例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，对于本领域的普通技术人员来讲，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附图。In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.
图1为本发明实施例提供的一种基于差分受激布里渊增益效应的直接测风激光雷达的结构示意图；Fig. 1 is a schematic structural diagram of a direct wind measurement laser radar based on differential stimulated Brillouin gain effect provided by an embodiment of the present invention;
图2为本发明实施例提供的图1中节点(a)、(b)、(c)、(d)、(e)处激光的频域图像；Fig. 2 is the frequency-domain image of the laser at nodes (a), (b), (c), (d), and (e) in Fig. 1 provided by the embodiment of the present invention;
图3为本发明实施例提供的图1中节点(a)、(b)、(c)、(d)、(e)处激光的时域图像；Fig. 3 is the time-domain image of the laser at nodes (a), (b), (c), (d), and (e) in Fig. 1 provided by the embodiment of the present invention;
图4为本发明实施例提供的构建受激布里渊散射光纤鉴频器的原理图。Fig. 4 is a schematic diagram of constructing a stimulated Brillouin scattering optical fiber discriminator provided by an embodiment of the present invention.
具体实施方式detailed description
下面结合本发明实施例中的附图，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，都属于本发明的保护范围。The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.
受激布里渊散射是一种非线性光学现象，在光纤光学中，其过程可以经典地描述为激光泵浦波、斯托克斯波通过声波而激发的非线性效应。泵浦波由电致伸缩效应在介质中产生声波，反过来声波对介质折射率进行调制。泵浦波感应的折射率光栅通过布拉格衍射散射泵浦波，由于以声速移动的光栅的多普勒位移，散射光产生了频率下移，下移的频率称为布里渊频移。本发明实施例的方案利用受激布里渊散射构建鉴频系统，简单、易控，适用于各个波段的激光雷达。且由于出射激光频率在频谱始终位于吸收峰与增益峰之间距离的中点位置，因此不需要进行频率锁定，减小了系统所产生的误差。其具有探测精度高、成本较低、结构紧凑等优点。Stimulated Brillouin scattering is a nonlinear optical phenomenon. In fiber optics, its process can be classically described as a nonlinear effect excited by laser pump waves and Stokes waves through acoustic waves. The pump wave generates an acoustic wave in the medium by the electrostrictive effect, which in turn modulates the refractive index of the medium. The refractive index grating induced by the pump wave scatters the pump wave through Bragg diffraction. Due to the Doppler shift of the grating moving at the speed of sound, the frequency of the scattered light shifts down, and the frequency of the down shift is called the Brillouin frequency shift. The scheme of the embodiment of the present invention uses stimulated Brillouin scattering to construct a frequency discrimination system, which is simple and easy to control, and is suitable for laser radars of various bands. And since the frequency of the outgoing laser is always located at the midpoint of the distance between the absorption peak and the gain peak in the frequency spectrum, no frequency locking is required, which reduces the error generated by the system. It has the advantages of high detection accuracy, low cost and compact structure.
图1为本发明实施例提供的一种基于差分受激布里渊增益效应的直接测风激光雷达的结构示意图。如图1所示，其主要包括：Fig. 1 is a schematic structural diagram of a direct wind measurement laser radar based on differential stimulated Brillouin gain effect provided by an embodiment of the present invention. As shown in Figure 1, it mainly includes:
连续光激光器1、相位/强度调制器2、微波信号发生器3、第一光纤环形器4、电光强度调制器5、第一掺铒光纤放大器6、望远镜发射端7、第一光纤布拉格光栅8、第二光纤布拉格光栅9、第二光纤环形器10、望远镜接收端11、第二掺铒光纤放大器12、隔离器13、第三光纤环形器14、分束器15、受激布里渊散射光纤16、第四光纤环形器17、第三光纤布拉格光栅18、第一探测器19、第二探测器20、第一采集卡21、第二采集卡22与计算机23；其中：CW laser 1, phase/intensity modulator 2, microwave signal generator 3, first fiber circulator 4, electro-optical intensity modulator 5, first erbium-doped fiber amplifier 6, telescope transmitting end 7, first fiber Bragg grating 8 , second fiber Bragg grating 9, second fiber circulator 10, telescope receiving end 11, second erbium-doped fiber amplifier 12, isolator 13, third fiber circulator 14, beam splitter 15, stimulated Brillouin scattering Optical fiber 16, fourth fiber optic circulator 17, third fiber Bragg grating 18, first detector 19, second detector 20, first acquisition card 21, second acquisition card 22 and computer 23; wherein:
连续光激光器1输出的激光载波信号经过相位/强度调制器2进行相位/强度调制后，产生两个在频域上对称的频率边带，激光载波信号和两频率边带信号入射至第一光纤环形器4的A端口，其中相位/强度调制器2的控制信号由微波信号发生器3提供。入射至第一光纤环形器4A端口的光先经由B端口到达第一光纤布拉格光栅8，其中激光载波信号被第一光纤布拉格光栅8反射并经过第一光纤环形器4的B端口由C端口出射至电光强度调制器5，电光强度调制器5将反射激光载波信号调制成脉冲光后由第一掺铒光纤放大器6放大，放大后的脉冲光由望远镜发射端7发射至大气当中；The laser carrier signal output by the continuous light laser 1 is phase/intensity modulated by the phase/intensity modulator 2 to generate two symmetrical frequency sidebands in the frequency domain, and the laser carrier signal and the two frequency sideband signals are incident on the first optical fiber The A port of the circulator 4, wherein the control signal of the phase/intensity modulator 2 is provided by the microwave signal generator 3. The light incident on the port A of the first fiber circulator 4 first reaches the first fiber Bragg grating 8 through the port B, where the laser carrier signal is reflected by the first fiber Bragg grating 8 and exits the port C through the port B of the first fiber circulator 4 To the electro-optical intensity modulator 5, the electro-optical intensity modulator 5 modulates the reflected laser carrier signal into pulsed light and then amplifies it by the first erbium-doped fiber amplifier 6, and the amplified pulsed light is emitted into the atmosphere by the telescope transmitting end 7;
两频率边带信号透过所述第一光纤布拉格光栅8，该信号通过第二掺铒光纤放大器12放大后经过隔离器13入射至第三光纤环形器14的A端口，透过的频率边带信号作为双频泵浦光经过第三光纤环形器14的B端口入射至受激布里渊散射光纤16的A端并由B端出射；The two-frequency sideband signal passes through the first fiber Bragg grating 8, and after the signal is amplified by the second erbium-doped fiber amplifier 12, it enters the A port of the third optical fiber circulator 14 through the isolator 13, and the transmitted frequency sideband The signal, as dual-frequency pumping light, is incident on the A-end of the stimulated Brillouin scattering fiber 16 through the B-port of the third optical fiber circulator 14 and emerges from the B-end;
由望远镜接收端11接收出射的脉冲光与大气相互作用产生的后向散射信号，该后向散射信号由望远镜接收端11入射至第二光纤环形器10的A端口，经过第二光纤环形器10的B端口入射至第二光纤布拉格光栅9，光纤布拉格光栅9将噪声信号去除后，将大气后向散射信号反射并由第二光纤环形器10的C端口出射，经过分束器15分为两路光，其中一路光经分束器15的A端口入射至受激布里渊散射光纤16的B端，进入受激布里渊散射光纤16后与频率边带信号所构成的双频泵浦光反向传输，产生受激布里渊散射，与双频泵浦光反向传输的信号光由第三光纤环形器14的B端口经C端口入射至第四光纤环形器17的A端口，并经过B端口入射至第三光纤布拉格光栅18对信号进行滤波，由第三光纤布拉格光栅18反射的信号经过第四光纤环形器17的B端口由C端口出射至第一探测器19，第一探测器19与第一采集卡21连接，由第一采集卡21将采集到的数据传输至计算机23。The backscattering signal generated by the interaction of the outgoing pulsed light and the atmosphere is received by the receiving end 11 of the telescope. The backscattering signal is incident on the A port of the second optical fiber circulator 10 by the receiving end 11 of the telescope, and passes through the second optical fiber circulator 10 The B port of the second fiber Bragg grating is incident to the second fiber Bragg grating 9. After the fiber Bragg grating 9 removes the noise signal, the atmospheric backscattering signal is reflected and emitted from the C port of the second fiber circulator 10, and is divided into two by the beam splitter 15. One path of light, wherein one path of light enters the B end of the stimulated Brillouin scattering fiber 16 through the A port of the beam splitter 15, enters the stimulated Brillouin scattering fiber 16 and forms a dual-frequency pump with frequency sideband signals The light is reversely transmitted to generate stimulated Brillouin scattering, and the signal light transmitted in reverse with the dual-frequency pump light is incident on the A port of the fourth optical fiber circulator 17 through the B port of the third optical fiber circulator 14 through the C port, And through the B port incident to the third fiber Bragg grating 18 to filter the signal, the signal reflected by the third fiber Bragg grating 18 passes through the B port of the fourth fiber circulator 17 and exits to the first detector 19 from the C port, the first The detector 19 is connected to the first acquisition card 21 , and the first acquisition card 21 transmits the collected data to the computer 23 .
由光分束器15产生的另一路光经过光分束器15的B端口与第二探测器20连接进行能量检测，第二探测器20与第二采集卡22连接，由第二采集卡22将采集到的数据传输至计算机23，由计算机23根据第一采集卡21与第二采集卡22传输的数据进行反演计算。Another road light produced by the optical beam splitter 15 is connected to the second detector 20 through the B port of the optical beam splitter 15 for energy detection, and the second detector 20 is connected to the second acquisition card 22, and the second acquisition card 22 The collected data is transmitted to the computer 23, and the computer 23 performs inversion calculation according to the data transmitted by the first acquisition card 21 and the second acquisition card 22.
图1所示的节点(a)、(b)、(c)、(d)、(e)处激光的频域、时域图像如图2-3所示，图2-3中的(a)～(e)与图1中的节点(a)～(e)相对应；图2中的A(v)表示幅值，图3中的I(t)表示强度，图3的(b)、(c)、(e)中实线表示使用相位调制器，虚线表示使用强度调制器。The frequency-domain and time-domain images of the laser at nodes (a), (b), (c), (d), and (e) shown in Figure 1 are shown in Figure 2-3, and (a )～(e) correspond to the nodes (a)～(e) in Figure 1; A(v) in Figure 2 represents the amplitude, I(t) in Figure 3 represents the intensity, and (b) in Figure 3 , (c), and (e) the solid line indicates the use of the phase modulator, and the dotted line indicates the use of the intensity modulator.
本发明实施例中，所述第一光纤布拉格光栅8、第二光纤布拉格光栅9与第三光纤布拉格光栅18均为均匀光纤布拉格光栅。In the embodiment of the present invention, the first Fiber Bragg Grating 8, the second Fiber Bragg Grating 9 and the third Fiber Bragg Grating 18 are uniform Fiber Bragg Gratings.
本发明实施例中，所述受激布里渊光纤16包括：单模光纤、保偏光纤、光子晶体光纤、单偏振光纤、塑料光纤或辐射光纤。In the embodiment of the present invention, the stimulated Brillouin fiber 16 includes: single mode fiber, polarization maintaining fiber, photonic crystal fiber, single polarization fiber, plastic fiber or radiation fiber.
本发明实施例中，所述受激布里渊光纤16利用受激布里渊散射产生透过率函数，作为鉴频器件，其工作过程如下：In the embodiment of the present invention, the stimulated Brillouin optical fiber 16 utilizes stimulated Brillouin scattering to generate a transmittance function as a frequency discrimination device, and its working process is as follows:
当所述连续光激光器1出射的激光经相位/强度调制器2调制后，其频域上两个频率边带的光透过第一光纤布拉格光栅8，经第二掺铒光纤放大器12放大后进入光纤16作为双频泵浦光。由望远镜接收端11接收的后向散射信号反向入射到受激布里渊光纤16中，并在受激布里渊光纤16中发生受激布里渊散射，在频域上形成信号强度透过率函数；此时激光出射频率固定在其在频谱上吸收峰与增益峰间隔距离的中点处(连续激光器频率到吸收峰和增益峰的距离Δ相等，如图4所示)；When the laser emitted by the continuous light laser 1 is modulated by the phase/intensity modulator 2, the light of the two frequency sidebands in the frequency domain passes through the first fiber Bragg grating 8 and is amplified by the second erbium-doped fiber amplifier 12 Enter the optical fiber 16 as dual-frequency pump light. The backscattering signal received by the receiving end 11 of the telescope is incident back into the stimulated Brillouin fiber 16, and stimulated Brillouin scattering occurs in the stimulated Brillouin fiber 16, forming a transparent signal intensity in the frequency domain. Overrate function; now the laser output frequency is fixed at the midpoint of the distance between the absorption peak and the gain peak on the spectrum (the distance Δ from the frequency of the continuous laser to the absorption peak and the gain peak is equal, as shown in Figure 4);
受激布里渊光纤16作为鉴频器件将望远镜接收端11接收到的后向散射信号中所携带的频率变化转化为在鉴频器所产生的陡峭边缘透过的信号强度或功率变化，并通过第二探测器20进行能量检测。The stimulated Brillouin fiber 16 is used as a frequency discriminator to convert the frequency change carried in the backscattered signal received by the telescope receiving end 11 into a signal intensity or power change transmitted through the steep edge generated by the frequency discriminator, and Energy detection is carried out by means of the second detector 20 .
为了便于理解本发明，下面结合附图4介绍基于差分受激布里渊增益效应的直接测风激光雷达原理：In order to facilitate understanding of the present invention, the principle of direct wind-measuring laser radar based on the differential stimulated Brillouin gain effect is introduced below in conjunction with accompanying drawing 4:
设连续激光器出射激光频率为v0，设微波信号发生器提供的信号频率为vm，经相位或强度调制器调制后，光场分别在v1＝v0-vm和v2＝v0+vm处产生两个频率边带。光场中激光载波频率分量v0经光纤光栅反射，经强度调制器调制为脉冲后进入望远镜发射端。Let the output laser frequency of the continuous laser be v0 , let the frequency of the signal provided by the microwave signal generator be vm , after being modulated by the phase or intensity modulator, the light fields are respectively at v1 =v0 -vm and v2 =v0 Two frequency sidebands are generated at +vm . The laser carrier frequency component v0 in the light field is reflected by the fiber grating, modulated by the intensity modulator into pulses, and then enters the transmitting end of the telescope.
光场中两个频率边带由光纤光栅透过，作为双频泵浦入射到受激布里渊散射光纤当中。在光纤中，由于受激布里渊散射，由双频泵浦其中频率较高的光在频谱v0+vm-vB位置产生增益，其中频率较低的光在频谱v0-vm+vB位置产生吸收(如图4所示)。可得到在这两个位置的受激布里渊增益分别为：The two frequency sidebands in the light field are transmitted by the fiber grating and incident into the stimulated Brillouin scattering fiber as a dual-frequency pump. In optical fiber, due to stimulated Brillouin scattering, the light with higher frequency generates gain in the position of spectrum v0 +vm -vB by double-frequency pumping, and the light with lower frequency in the position of spectrum v0 -vm Absorption occurs at the +vB position (as shown in Figure 4). The stimulated Brillouin gains at these two positions can be obtained as:
式中，g0表示布里渊增益峰值，ΔvB表示布里渊增益谱的半高全宽，vB表示布里渊频移。In the formula, g0 represents the peak value of the Brillouin gain, ΔvB represents the full width at half maximum of the Brillouin gain spectrum, and vB represents the Brillouin frequency shift.
布里渊频移vB和布里渊谱宽ΔvB均与光纤材料、温度T及光纤所受应力ε有关，在材料选定的情况下，通过改变温度可改变布里渊增益的谱宽，通过改变微波信号频率可以改变受激布里渊增益和吸收的频率位置。通过适当调节，可得到在吸收峰与增益峰之间连续变化且变化趋势单调的混合布里渊增益谱，其可以表示为：Both the Brillouin frequency shift vB and the Brillouin spectral width ΔvB are related to the fiber material, temperature T and the stress ε on the fiber. When the material is selected, the spectral width of the Brillouin gain can be changed by changing the temperature. The frequency position of stimulated Brillouin gain and absorption can be changed by changing the microwave signal frequency. Through proper adjustment, a mixed Brillouin gain spectrum with a continuous change between the absorption peak and the gain peak and a monotonous change trend can be obtained, which can be expressed as:
由此，可以得到信号光的增益函数exp(gB12P0Leff/Aeff-αL)，其中P0为双频泵浦功率，α为光纤损耗系数，L为光纤长度，Leff＝[1-exp(-αL)]/α为有效光纤长度，Aeff为光纤有效模面积，可由此得到信号的透过率函数。这时，受激布里渊散射光纤便可以作为一种鉴频器件，其将经过大气返回的信号所携带的微小频率变化转化为在鉴频器所产生的陡峭边缘透过的信号强度或功率变化，并通过探测器测量，得到多普勒频移vD，进行风速反演。径向风速VLOS表示为：Thus, the gain function exp(gB12 P0 Leff /Aeff -αL) of the signal light can be obtained, where P0 is the dual-frequency pump power, α is the fiber loss coefficient, L is the fiber length, and Leff =[ 1-exp(-αL)]/α is the effective fiber length, and Aeff is the effective mode area of the fiber, from which the transmittance function of the signal can be obtained. At this time, the stimulated Brillouin scattering fiber can be used as a frequency discrimination device, which converts the small frequency change carried by the signal returned through the atmosphere into the signal strength or power transmitted through the steep edge generated by the frequency discriminator Change, and through the detector measurement, get the Doppler frequency shift vD , and carry out the wind speed inversion. The radial wind speed VLOS is expressed as:
式中，λ为激光波长。In the formula, λ is the laser wavelength.
本发明实施例提供的一种基于差分受激布里渊增益效应的直接测风激光雷达具有如下有益效果：A direct wind measurement laser radar based on differential stimulated Brillouin gain effect provided by the embodiment of the present invention has the following beneficial effects:
1)本发明采用双频泵浦光抽运光纤构成鉴频器，相比于采用Fabry-Perot标准具作为鉴频器，该鉴频器结构简单、成本较低、易于实现激光雷达系统小型化，且该鉴频器在使用温控等环境控制设备情况下，稳定性高。1) The present invention uses dual-frequency pump light to pump optical fibers to form a frequency discriminator. Compared with using the Fabry-Perot etalon as a frequency discriminator, the frequency discriminator has a simple structure, low cost, and is easy to realize the miniaturization of the laser radar system , and the discriminator has high stability when using environmental control equipment such as temperature control.
2)本发明中采用双频泵浦光抽运光纤构成鉴频器，由于该鉴频器的使用，使得激光出射频率固定在其在频谱上吸收峰与增益峰间隔距离的中点处(连续激光器频率到吸收峰和增益峰的距离Δ相等，如图4所示)，因而不再需要对激光频率进行锁定，因而简化了系统结构同时又减小了测量误差。2) In the present invention, dual-frequency pumping light is used to pump the optical fiber to form a frequency discriminator. Due to the use of this frequency discriminator, the laser emission frequency is fixed at the midpoint of the distance between the absorption peak and the gain peak on the frequency spectrum (continuous The distance Δ from the laser frequency to the absorption peak and the gain peak is equal, as shown in Figure 4), so it is no longer necessary to lock the laser frequency, thus simplifying the system structure and reducing the measurement error.
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 is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person familiar with the technical field can easily conceive of changes or changes within the technical scope disclosed in the present invention. Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.
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| CN201610846712.4ACN106154289B (en) | 2016-09-23 | 2016-09-23 | Direct anemometry laser radar based on difference excited Brillouin enhancement effect |
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| CN201610846712.4ACN106154289B (en) | 2016-09-23 | 2016-09-23 | Direct anemometry laser radar based on difference excited Brillouin enhancement effect |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106769952A (en)* | 2017-03-02 | 2017-05-31 | 南京红露麟激光雷达科技有限公司 | Gas DIAL based on incoherent light source |
| CN106940444A (en)* | 2017-02-27 | 2017-07-11 | 南京红露麟激光雷达科技有限公司 | Coherent Doppler wind-observation laser radar based on microwave differential gain |
| CN108594256A (en)* | 2018-04-16 | 2018-09-28 | 合肥菲涅尔光电科技有限公司 | A kind of coherent laser radar based on pulse coding technique |
| CN110268230A (en)* | 2017-02-01 | 2019-09-20 | Hrl实验室有限责任公司 | The optical heterodyne of air pressure, temperature and wind speed detects and method |
| CN110346777A (en)* | 2018-04-03 | 2019-10-18 | 通用汽车环球科技运作有限责任公司 | Image intensifer in coherent lidar system return path |
| CN110914706A (en)* | 2017-03-22 | 2020-03-24 | 默特科气象测量技术有限责任公司 | LIDAR measuring device |
| CN112327272A (en)* | 2020-11-06 | 2021-02-05 | 深圳煜炜光学科技有限公司 | Pulse-codable laser radar device and detection method thereof |
| CN113176582A (en)* | 2021-04-27 | 2021-07-27 | 厦门大学 | Flow velocity detection laser radar and flow velocity detection method based on double-frequency pumping |
| CN114778879A (en)* | 2022-04-11 | 2022-07-22 | 中国工程物理研究院流体物理研究所 | Speed measuring device and method based on optical fiber stimulated Brillouin scattering |
| 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 |
| CN116165433A (en)* | 2023-04-25 | 2023-05-26 | 之江实验室 | Microwave photonics measuring device and method based on fiber Bragg grating |
| CN119375861A (en)* | 2024-10-21 | 2025-01-28 | 中国科学院合肥物质科学研究院 | Rayleigh wind lidar frequency discrimination method and system |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110268230B (en)* | 2017-02-01 | 2022-04-29 | Hrl实验室有限责任公司 | Optical heterodyne detection and method of air pressure, temperature, and wind speed |
| CN110268230A (en)* | 2017-02-01 | 2019-09-20 | Hrl实验室有限责任公司 | The optical heterodyne of air pressure, temperature and wind speed detects and method |
| CN106940444A (en)* | 2017-02-27 | 2017-07-11 | 南京红露麟激光雷达科技有限公司 | Coherent Doppler wind-observation laser radar based on microwave differential gain |
| CN106940444B (en)* | 2017-02-27 | 2019-09-13 | 南京红露麟激光雷达科技有限公司 | Coherent Doppler wind-observation laser radar based on microwave differential gain |
| CN106769952B (en)* | 2017-03-02 | 2019-09-13 | 南京红露麟激光雷达科技有限公司 | Gas differential absorption lidar based on incoherent light source |
| CN106769952A (en)* | 2017-03-02 | 2017-05-31 | 南京红露麟激光雷达科技有限公司 | Gas DIAL based on incoherent light source |
| CN110914706A (en)* | 2017-03-22 | 2020-03-24 | 默特科气象测量技术有限责任公司 | LIDAR measuring device |
| CN110914706B (en)* | 2017-03-22 | 2024-01-12 | 默特科气象测量技术有限责任公司 | LIDAR measuring device |
| CN110346777A (en)* | 2018-04-03 | 2019-10-18 | 通用汽车环球科技运作有限责任公司 | Image intensifer in coherent lidar system return path |
| CN108594256A (en)* | 2018-04-16 | 2018-09-28 | 合肥菲涅尔光电科技有限公司 | A kind of coherent laser radar based on pulse coding technique |
| CN112327272A (en)* | 2020-11-06 | 2021-02-05 | 深圳煜炜光学科技有限公司 | Pulse-codable laser radar device and detection method thereof |
| CN112327272B (en)* | 2020-11-06 | 2021-06-29 | 深圳煜炜光学科技有限公司 | Pulse-codable laser radar device and detection method thereof |
| CN113176582A (en)* | 2021-04-27 | 2021-07-27 | 厦门大学 | Flow velocity detection laser radar and flow velocity detection method based on double-frequency pumping |
| CN114778879A (en)* | 2022-04-11 | 2022-07-22 | 中国工程物理研究院流体物理研究所 | Speed measuring device and method based on optical fiber stimulated Brillouin scattering |
| 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 |
| CN116165433A (en)* | 2023-04-25 | 2023-05-26 | 之江实验室 | Microwave photonics measuring device and method based on fiber Bragg grating |
| CN119375861A (en)* | 2024-10-21 | 2025-01-28 | 中国科学院合肥物质科学研究院 | Rayleigh wind lidar frequency discrimination method and system |
| Publication number | Publication date |
|---|---|
| CN106154289B (en) | 2018-09-07 |
| Publication | Publication Date | Title |
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| CF01 | Termination of patent right due to non-payment of annual fee | Granted publication date:20180907 |