CN108761485B - Fabry-Perot interferometer, interference device and Doppler wind lidar - Google Patents

Abstract

The invention discloses a Fabry-Perot interferometer, an interference device and a Doppler wind lidar, wherein the Fabry-Perot interferometer comprises: the first light-transmitting substrate and the second light-transmitting substrate are oppositely arranged; the Fabry-Perot interferometer has two optical channels; the free spectrum spacing of the Fabry-Perot interferometer is equal to 1/n of Doppler frequency shift caused by satellite flight, and n is a positive integer greater than 1; the center frequency separation of the two channels in the Fabry-Perot interferometer is equal to half of the free spectral spacing. The Fabry-Perot interferometer is simple in structure, high in measurement accuracy and convenient for engineering application, and the problem that emergent light frequency cannot be locked is solved. The Doppler wind lidar adopting the Fabry-Perot interferometer has higher measurement precision and reliability.

Description

Fabry-Perot Interferometer, Interferometer and Doppler Wind Lidar

technical field

The invention relates to the technical field of optical elements, and more particularly, to a Fabry-Perot interferometer, an interference device and a Doppler wind-measuring laser radar.

Background technique

With its high resolution, high precision, large detection range, and the ability to provide three-dimensional wind field information, Doppler wind Lidar has important applications in climate research and weather forecasting, attracting the attention of many countries in the world, and has invested in it. A lot of manpower and material resources for research. According to different detection methods, Doppler wind Lidar technology can be divided into coherent technology and incoherent (direct detection) technology. The direct technique is to use the transmittance of the backscattered echo signal of atmospheric molecules through the frequency discriminator to invert to obtain the wind speed, which can be used to detect the atmospheric wind field in the troposphere and stratosphere.

As the core component of the direct detection Doppler wind Lidar, the Fabry-Perot interferometer directly affects the accuracy of the measurement results. The existing Fabry-Perot interferometer technologies mainly include: Single-channel and dual-channel (or dual-edge technology), of which the dual-channel Fabry-Perot interferometer has become the main technology used in the currently developed wind measurement lidar because of its higher measurement accuracy. However, the structure of the interferometer The selection of form and parameters will directly affect the accuracy of measurement and the convenience in engineering applications. The Fabry-Perot interferometer used in the current Doppler wind measurement lidar is difficult to apply in engineering, and it is easy to appear that the frequency of the outgoing light cannot be used. locking, etc.

SUMMARY OF THE INVENTION

In order to solve the above problems, the technical solution of the present invention provides a Fabry-Perot interferometer, an interference device and a Doppler wind measurement lidar. The Fabry-Perot interferometer has a simple structure and high measurement accuracy. It is convenient for engineering application and avoids the problem that the frequency of the outgoing light cannot be locked.

In order to achieve the above object, the present invention provides the following technical solutions:

A Fabry-Perot interferometer, used for a Doppler wind measurement lidar carried by a satellite, the Fabry-Perot interferometer comprising:

a first light-transmitting substrate and a second light-transmitting substrate arranged oppositely;

The Fabry-Perot interferometer has two optical channels;

Wherein, the free spectral spacing of the Fabry-Perot interferometer is equal to 1/n of the Doppler frequency shift caused by satellite flight, and n is a positive integer greater than 1; in the Fabry-Perot interferometer The center frequency separation of the two channels is equal to half the free spectral spacing.

Preferably, in the above-mentioned Fabry-Perot interferometer, there is a light-transmitting filling medium between the first light-transmitting substrate and the second light-transmitting substrate, and the transmittance of the light-transmitting filling medium is greater than 99 %, the thermal expansion coefficient is less than 0.5/MK.

Preferably, in the above Fabry-Perot interferometer, the light-transmitting filling medium is glass-ceramic.

Preferably, in the above-mentioned Fabry-Perot interferometer, the free spectral spacing of the Fabry-Perot interferometer is equal to 10.95 GHz, the center frequency spacing of the two channels is equal to 5.475 GHz, and the half of the transmittance curve is equal to 5.475 GHz. The height and width are equal to 1.56GHz.

The present invention also provides an interference device, the interference device comprising:

1/4 wave plate, the 1/4 wave plate has opposite first side and second side;

a polarizing beam splitting prism group, the polarizing beam splitting prism group is arranged opposite to the first surface;

A dual-channel Fabry-Perot interferometer, the Fabry-Perot interferometer is disposed opposite to the second surface;

Wherein, the Fabry-Perot interferometer is the Fabry-Perot interferometer described in any one of claims 1-4.

Preferably, in the above interference device, the polarizing beam splitting prism group has three identical isosceles right-angled prisms, and the isosceles right-angled prisms have one hypotenuse side and two identical straight side faces;

The three isosceles right-angle prisms are sequentially the first isosceles right-angle prism, the second isosceles right-angle prism and the third isosceles right-angle prism;

The hypotenuse side of the first isosceles right angle prism is fixed with the hypotenuse side of the second isosceles right angle prism; the two form a cube;

A straight side surface of the third isosceles right angle prism is fixed with a straight side surface of the second isosceles right angle prism, and the hypotenuse side surface of the third isosceles right angle prism is connected to the second isosceles right angle prism. The side of the hypotenuse is vertical;

The other straight side surface of the third isosceles right triangle prism and the other straight side surface of the second isosceles right triangle prism are coplanar, and the plane is arranged opposite to the first surface.

The present invention also provides a Doppler wind measurement laser radar, and the Doppler laser wind measurement radar includes:

an emission system, the emission system is used to emit detection laser light;

A receiving system, which is used to obtain the echo signal of the detection laser from the atmosphere; the receiving system includes the interference device according to any one of claims 5 or 6, which has a polarizing beam splitting prism group, 1/4 Waveplates and dual-channel Fabry-Perot interferometers;

a processing device, the processing device is configured to measure the atmospheric wind field based on the echo signal;

Wherein, when the Doppler wind-measuring lidar works, the echo signal enters the polarization beam splitting prism group, and a part of the echo signal directly passes through the 1/4 wave plate, and then passes through the Fabry- One channel of the Perot interferometer exits directly, and the other part of the echo signal is reflected back to the polarization beam splitter prism group through the Fabry-Perot interferometer. After two reflections in the polarization beam splitter prism group, Outgoing through the polarizing beam splitting prism group, entering the Fabry-Perot interferometer through the quarter wave plate, and outgoing through another channel of the Fabry-Perot interferometer.

It can be seen from the above description that the Fabry-Perot interferometer provided by the technical solution of the present invention includes: a first light-transmitting substrate and a second light-transmitting substrate arranged oppositely; the Fabry-Perot interferometer has two optical channel; wherein, the free spectral spacing of the Fabry-Perot interferometer is equal to 1/n of the Doppler frequency shift caused by satellite flight, and n is a positive integer greater than 1; the Fabry-Perot interferometer The center frequency spacing of the two channels in the instrument is equal to half the free spectral spacing. The Fabry-Perot interferometer has a simple structure, high measurement accuracy, is convenient for engineering applications, and avoids the problem that the frequency of the outgoing light cannot be locked. The Doppler wind lidar using the Fabry-Perot interferometer has higher measurement accuracy and reliability.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a schematic structural diagram of a Fabry-Perot interferometer provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an interference device according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of 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.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Referring to FIG. 1, FIG. 1 is a schematic structural diagram of a Fabry-Perot interferometer according to an embodiment of the present invention, and the Fabry-Perot interferometer 13 shown in FIG. 1 is used for satellite-mounted Doppler wind measurement For a lidar, the Fabry-Perot interferometer 13 includes: a first light-transmitting substrate 131 and a second light-transmitting substrate 132 arranged oppositely.

The Fabry-Perot interferometer 13 has two optical channels. Wherein, the free spectral spacing of the Fabry-Perot interferometer 13 is equal to 1/n of the Doppler frequency shift caused by satellite flight, and n is a positive integer greater than 1; the Fabry-Perot interferometer The center frequency spacing of the two channels in 13 is equal to half the free spectral spacing. Specifically, the free spectral spacing of the Fabry-Perot interferometer 13 is equal to 10.95 GHz, the center frequency spacing of the two channels is equal to 5.475 GHz, and the full width at half maximum of the transmittance curve is equal to 1.56 GHz.

Optionally, there is a transparent filling medium 133 between the first transparent substrate 131 and the second transparent substrate 132, the transmittance of the transparent filling medium 133 is greater than 99%, and the thermal expansion coefficient is less than 0.5/ MK. Specifically, the transparent filling medium 133 may be glass-ceramic. The light-transmitting filling medium 133 is a solid substance. The light-transmitting filling medium 133 has a very small coefficient of thermal expansion. Through the light-transmitting filling medium, the distance between the two substrates can not be changed by the influence of temperature, has good light transmittance, and can ensure the accuracy of the interferometer.

The technical solution described in the embodiment of the present invention designs a new type of Fabry-Perot interferometer 13 based on a specific parameter design method, and uses a solid material with a very small thermal expansion coefficient such as glass-ceramic as the cavity filling, and the cavity length is Non-tunable, the parameters of the Fabry-Perot interferometer 13 are specially designed, which greatly improves the frequency discrimination accuracy and stability.

The design scheme of the Fabry-Perot interferometer 13 according to the embodiment of the present invention includes two aspects: optical structure design and interferometer parameter design.

1) Optical structure design

The traditional Fabry-Perot interferometer for direct detection Doppler wind lidar consists of three optical channels, two signal channels for detecting atmospheric echo signals and one for locking channel. The optical signal passing through the locking channel is used to lock the frequency of the outgoing detection laser light at the intersection of the transmittance curves of the corresponding signals in the two signal channels. The Fabry-Perot interferometer with this structure is not only complicated in structure and high in manufacturing cost, but also in the actual measurement, the channel locking often leads to large systematic errors due to low precision, which reduces the measurement accuracy. The Fabry-Perot interferometer described in the embodiment of the present invention is composed of two channels, and both the outgoing detection laser frequency and the atmospheric echo signal frequency are measured by these two channels. Wave signals) are separated in the time domain. Compared with the traditional three-channel design method, the Fabry-Perot interferometer according to the embodiment of the invention can improve the measurement accuracy of the outgoing detection laser, thereby improving the wind speed measurement accuracy. Eliminate the systematic error caused by measuring the frequency of the outgoing laser and the frequency of the echo signal with different optical paths.

2) Interferometer parameter design

For the parameter design of the two-channel Fabry-Perot interferometer, there are mainly three parameters, the free spectral spacing FSR, the center frequency interval Δv of the two channels, and the transmittance curve FWHM of the two channels.

The selection of these three parameters not only takes into account the processing and manufacturing capabilities, but also determines the frequency detection accuracy of the interferometer. The Fabry-Perot interferometer comprehensively considers the above two factors, and the inventor proposes a dual-channel Fabry-Perot interferometer that is generally applicable to Doppler wind Lidar based on years of Lidar application experience in the laboratory. The parameter optimization scheme of the instrument is highly innovative.

First of all, the selection of the free spectral distance FSR usually takes into account the spectral width of the molecular backscattering spectrum and the working status of the Doppler wind lidar. The Fabry-Perot interferometer designed this time is used for satellite platforms. The speed of the platform and the distribution of its orbits can be calculated to obtain the component of the Doppler frequency shift caused by the satellite flight in the laser output direction. In order to eliminate the error caused by this frequency shift to the measurement, the free spectral spacing FSR can be selected as the satellite 1/n of the Doppler frequency shift caused by flight (n is a positive integer), n is a positive integer greater than 1, and an appropriate value of n is selected in combination with the limitation of the processing accuracy of the Fabry-Perot interferometer to select the appropriate freedom Spectral Spacing FSR.

Secondly, the interval Δv between the two channels is selected as half of the FSR. At this time, the transmittance curves of the two channels are symmetrical about the intersection of the two curves, so that the tunable pulsed laser is used to scan the Fabry-Perot interferometer. In the transmittance curve, only 1/2 of the FSR can be scanned to obtain a complete transmittance curve, which greatly reduces the wavelength tuning range requirements for the CW laser, which is of great significance for engineering applications.

Finally, when both FSR and Δv are determined, the systematic error caused by the Fabry-Perot interferometer for wind speed measurement is a single-valued function of FWHM, and the FWHM that minimizes the error is selected as the design parameter.

According to the above parameter optimization scheme, the embodiment of the present invention designs the above-mentioned Fabry-Perot interferometer for spaceborne Doppler wind measurement lidar. The parameters are as follows: FSR is 10.95 GHz, and the peak interval δv of channel 1 and channel 2 is 5.475GHz, and the peak half-width FWHM of the transmittance curve is 1.56GHz.

The Fabry-Perot interferometer described in the embodiment of the present invention has the following advantages:

The measurement function of the traditional three-channel Fabry-Perot interferometer of the traditional wind-measuring lidar system is realized with two signal channels, and the accuracy is higher.

The echo signal passes through two channels in sequence. Compared with the traditional two-channel Fabry-Perot interferometer, which divides the signal light into two and enters different channels respectively, the Fabry-Perot interferometer according to the embodiment of the present invention The utilization rate of the echo signal is doubled, and the signal-to-noise ratio of the system is improved.

The parameters of the optimized Fabry-Perot interferometer are comprehensively considered from the aspects of engineering application and measurement accuracy, so that the transmittance curves of the two signal channels of the interferometer are symmetrical about the intersection of the two curves, which greatly reduces the need for continuous tunable pulses. The requirements for the wavelength tuning range of the laser are more conducive to engineering implementation.

Based on the Fabry-Perot interferometer described in the above embodiment, another embodiment of the present invention further provides an interference device, as shown in FIG. 2 , which is a structure of an interference device provided by an embodiment of the present invention Schematic diagram, the interference device shown in FIG. 2 includes: a quarter wave plate 12, the quarter wave plate 12 has a first surface and a second surface opposite to each other; a polarizing beam splitting prism group 11, the polarizing beam splitting prism group 11 and the The first surface is arranged opposite to each other; a dual-channel Fabry-Perot interferometer 13 is arranged opposite to the second surface. Wherein, the Fabry-Perot interferometer is the Fabry-Perot interferometer described in the above embodiment.

As shown in FIG. 2 , the polarizing beam splitting prism group 11 has three identical isosceles right-angled triangular prisms, the isosceles right-angled triangular prisms have one hypotenuse side and two identical straight side faces, the top and bottom surfaces of which are positive Pair set of two identical isosceles right triangles. The three isosceles right-angle prisms are sequentially a first isosceles right-angle prism 111 , a second isosceles right-angle prism 112 and a third isosceles right-angle prism 113 .

The hypotenuse side surface of the first isosceles right angle triangular prism 111 and the hypotenuse side surface of the second isosceles right angle prism 112 are attached and fixed to form a cube. A straight side surface of the third isosceles right angle prism 113 is fixed with a straight side surface of the second isosceles right angle prism 112, and the hypotenuse side of the third isosceles right angle prism 113 is the same as the second isosceles right angle prism 113. The side surfaces of the hypotenuse of the waist right-angle prism 112 are vertical. The other straight side surface of the third isosceles right angle prism 113 and the other straight side surface of the second isosceles right angle prism 112 are coplanar, and the plane is disposed opposite to the first surface.

The interference device is composed of an optically bonded polarizing beam splitting prism group 11 , a quarter wave plate 12 and a Fabry-Perot interferometer 13 . The hypotenuse side surfaces of the isosceles right-angle triangular prisms in the polarizing beam splitting prism group 11 have reflective layers. The Fabry-Perot interferometer 13 has a solid filling substance between two substrates arranged in parallel.

The working process is as follows: the initial incident atmospheric scattered light (echo signal) and the outgoing detection laser are both linearly polarized light, and the angle of the polarized beam splitting prism group 11 matches the polarization direction of the laser, so that the incident polarized light can pass through the polarized light. The beam splitting prism group 11, the transmitted linearly polarized laser becomes circularly polarized light after passing through the 1/4 wave plate 12, and the circularly polarized light is divided into two parts, transmission and reflection, by a channel of the Fabry-Perot interferometer 13. The proportion of reflection is related to the frequency of the light. The transmitted part enters the subsequent optical path and is captured by the detector. The reflected part of the light passes through the 1/4 wave plate 12 again, and its polarization direction becomes perpendicular to the initial incident light. When the prism group 11 is used, two reflections will occur in the polarization beam splitting prism group 11. The light after the two reflections passes through the 1/4 wave plate 12 and then enters another channel of the Fabry-Perot interferometer 13. The latter part of the light is transmitted and part of the light is reflected. The transmitted light is captured by the detector through the subsequent optical path. The reflected light passes through the 1/4 wave plate 12 again and becomes linearly polarized light with the polarization direction parallel to the paper surface. Transmission occurs at the polarizing beam splitter prism group 11 and enters the outside of the system.

The two kinds of light, the reference laser separated by the outgoing detection laser and the echo signal scattered by the atmosphere, pass through the two channels of the Fabry-Perot interferometer in turn according to the above working process, and the two kinds of light can be obtained through the Fabry-Perot interferometer. The light intensities I _R1 and I _R2 , I ₁ and I ₂ of the two channels of the Rowe interferometer, and I _R1 and I _R2 are substituted into the laser pulse frequency response function of the Fabry-Perot interferometer 13 to obtain the outgoing detection laser The frequency v _L , I ₁ and I ₂ are substituted into the Rayleigh scattering frequency response function v of the Fabry-Perot interferometer 13, vv _L is the Doppler frequency shift caused by the atmospheric motion, so as to obtain the atmospheric wind speed. I _R1 and I _R2 are the light intensities corresponding to the detection laser in the two channels respectively, and I ₁ and I ₂ are the lights corresponding to the echo signals in the two channels respectively.

In the traditional double-edge interferometer, the atmospheric echo signal light is divided into two and enters the two channels respectively. The signal is all incident on a channel first, and a part of the light enters the subsequent optical path through the Fabry-Perot interferometer 13 in this channel, and after the other part of the light is reflected in this channel, the part of the light passes through the λ/4 wave twice. Plate 12, the polarization state changes by 90 degrees. After the other part of the light is reflected in this channel, after passing through the λ/4 wave plate 12 for the first time, it enters the polarizing beam splitting prism group 11 , is reflected twice in the polarizing beam splitting prism group 11 , and exits through the polarizing beam splitting prism group 11 . After that, the λ/4 wave plate 12 is incident, and after passing through the λ/4 wave plate 12 for the second time, it is incident on another channel of the Fabry-Perot interferometer 13 . In this way, compared with the traditional two-channel Fabry-Perot interferometer, the utilization rate of the signal light is nearly doubled, thereby improving the signal-to-noise ratio of the measurement signal and improving the measurement accuracy.

The Fabry-Perot interferometer adopts a full-space optical path structure, and a polarization beam splitting prism group is used to replace the previous fiber beam splitting structure, which improves the stability of the interferometer.

Based on the Fabry-Perot interferometer and the interferometric device described in the foregoing embodiments, another embodiment of the present invention further provides a Doppler wind measurement lidar, where the Doppler laser wind measurement radar includes: a transmitting system , receiving system and processing device.

The emitting system is used for emitting detection laser light. The receiving system is used for acquiring the echo signal of the detection laser from the atmosphere. The receiving system includes the interference device described in the above embodiment, which has a polarizing beam splitting prism group, a quarter-wave plate and a dual-channel Fabry-Perot interferometer. The processing device is used for measuring the atmospheric wind field based on the echo signal. The processing device may be an industrial control host.

Wherein, when the Doppler wind-measuring lidar is working, the echo signal enters the polarization beam splitting prism group, and a part of the echo signal (as shown by the straight arrow in FIG. 2 ) directly passes through the quarter wave After the film, one channel of the Fabry-Perot interferometer exits directly, and the other part of the echo signal (as shown by the folded arrow in Figure 2) is reflected back through the Fabry-Perot interferometer. The polarizing beam splitting prism group, after being reflected twice in the polarizing beam splitting prism group, exits through the polarizing beam splitting prism group, and enters the Fabry-Perot interferometer through the 1/4 wave plate, Exit through another channel of the Fabry-Perot interferometer.

The Doppler wind measurement lidar according to the embodiment of the present invention adopts the Fabry-Perot interferometer of the above embodiment, which has higher measurement accuracy and reliability, is convenient for engineering applications, and avoids the problem that the frequency of the outgoing light cannot be locked .

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the interferometric device and the Doppler wind-measuring lidar disclosed in the embodiment, since they correspond to the Fabry-Perot interferometer disclosed in the embodiment, the description is relatively simple. The Perot Interferometer section can be explained.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. a Fabry-Perot interferometer, for the Doppler wind measurement lidar carried by a satellite, it is characterized in that, described Fabry-Perot interferometer comprises: a first light-transmitting substrate and a second light-transmitting substrate arranged oppositely; The Fabry-Perot interferometer has two optical channels, and the two optical channels are used to measure the frequency of the atmospheric echo signal and also to measure the frequency of the outgoing detection laser; Wherein, the free spectral spacing of the Fabry-Perot interferometer is equal to 1/n of the Doppler frequency shift caused by satellite flight, and n is a positive integer greater than 1; in the Fabry-Perot interferometer The center frequency spacing of the two channels is equal to half of the free spectral spacing; There is a transparent filling medium between the first transparent substrate and the second transparent substrate, the transmittance of the transparent filling medium is greater than 99%, and the thermal expansion coefficient is less than 0.5/MK. 2 . The Fabry-Perot interferometer according to claim 1 , wherein the light-transmitting filling medium is glass-ceramic. 3 . 3. The Fabry-Perot interferometer according to claim 1, wherein the free spectral spacing of the Fabry-Perot interferometer is equal to 10.95 GHz, and the center frequency spacing of the two channels is equal to 5.475 GHz , the full width at half maximum of the transmittance curve is equal to 1.56GHz. 4. An interference device, characterized in that the interference device comprises: 1/4 wave plate, the 1/4 wave plate has opposite first side and second side; a polarizing beam splitting prism group, the polarizing beam splitting prism group is arranged opposite to the first surface; A dual-channel Fabry-Perot interferometer, the Fabry-Perot interferometer is disposed opposite to the second surface; Wherein, the Fabry-Perot interferometer is the Fabry-Perot interferometer described in any one of claims 1-3. 5 . The interference device according to claim 4 , wherein the polarizing beam splitting prism group has three identical isosceles right-angled triangular prisms, and the isosceles right-angled triangular prisms have one hypotenuse side surface and two identical straight sides. 6 . side; The three isosceles right-angle prisms are sequentially the first isosceles right-angle prism, the second isosceles right-angle prism and the third isosceles right-angle prism; The hypotenuse side of the first isosceles right angle prism is fixed with the hypotenuse side of the second isosceles right angle prism; the two form a cube; A straight side surface of the third isosceles right angle prism is fixed with a straight side surface of the second isosceles right angle prism, and the hypotenuse side surface of the third isosceles right angle prism is connected to the second isosceles right angle prism. The side of the hypotenuse is vertical; The other straight side surface of the third isosceles right triangle prism and the other straight side surface of the second isosceles right triangle prism are coplanar, and the plane is arranged opposite to the first surface. 6. A Doppler wind-measuring lidar, wherein the Doppler wind-measuring lidar comprises: a launch system, the launch system is used to launch the detection laser; a receiving system, the receiving system is used to obtain the echo signal of the detection laser from the atmosphere; the receiving system comprises the interference device according to any one of claims 4 or 5, which has a polarizing beam splitting prism group, 1/4 Waveplates and dual-channel Fabry-Perot interferometers; a processing device, the processing device is configured to measure the atmospheric wind field based on the echo signal; Wherein, when the Doppler wind-measuring lidar works, the echo signal enters the polarization beam splitting prism group, and a part of the echo signal directly passes through the 1/4 wave plate, and then passes through the Fabry- One channel of the Perot interferometer exits directly, and the other part of the echo signal is reflected back to the polarization beam splitter prism group through the Fabry-Perot interferometer. After two reflections in the polarization beam splitter prism group, Outgoing through the polarizing beam splitting prism group, entering the Fabry-Perot interferometer through the quarter wave plate, and outgoing through another channel of the Fabry-Perot interferometer.

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