All-solid-state all-time sodium layer wind temperature detection laser radar based on LD pumping technology

Abstract

According to the all-solid-state all-time sodium layer wind temperature detection laser radar based on the LD pumping technology, a first telescope is connected with a signal detection unit through a first 589nm optical fiber, a second telescope is connected with the signal detection unit through a second 589nm optical fiber, a third telescope is connected with the signal detection unit through a third 589nm optical fiber, and the signal detection unit is connected with a computer. The laser emitting unit is connected with the computer; the 1319nm continuous light seed laser is connected with the 1319nm optical fiber splitter through a first 1319nm optical fiber, the 1319nm optical fiber splitter is connected with the 1319nm seed injection module through a second 1319nm optical fiber, the 1319nm seed injection module is connected with the seed injection controller, and the output end of the seed injection module is connected with the input end of the LD end face pump amplifier. The laser radar is good in stability, the three-frequency switching speed is higher, and the frequency switching range is flexible and variable.

Description

Technical Field

[0001] The present invention relates to an improvement in lidar technology, belonging to the field of atmospheric remote sensing, and particularly to an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology. Background Art

[0002] The mesosphere-thermosphere (MLT) region of the Earth is rich in metal atom / ion layers containing various metal components such as Na, Fe, K, Ca, and Ca+, which usually originate from the ablation process of meteors. The complex atmospheric dynamics and photochemical processes in this region (such as the influence of gravity waves, planetary waves, tidal waves, solar wind, and solar electromagnetic radiation) make the detection of this layer extremely challenging. Due to the extremely large fluorescence scattering cross-section of sodium atoms, sodium wind temperature lidar can become an important tool for studying the MLT region by measuring parameters such as the atomic number density, wind field, and temperature of sodium atoms.

[0003] In order to achieve rapid and accurate detection of sodium atom density, temperature, and wind field in the mesosphere-thermosphere, existing technologies mostly use dye lasers as detection means. The advantages of dye lasers are wide spectral coverage, high pumping efficiency, and simple structure. Therefore, dye lasers have become the main means for lidar metal layer detection. However, the service life of dyes is limited and needs to be replaced regularly. In some remote areas or field environments with difficult conditions, the long-term high-power operation of the laser will cause the performance of the dye to possibly decline further, which will affect the reliability of the dye laser, thus making the long-term stability of the entire lidar worse.

[0004] The Chinese patent application with the application number CN202411292047.X and the application date of September 14, 2024, discloses a three-frequency laser generation device and method for a fiber-optic fast sodium temperature and wind measurement lidar, belonging to the technical field of multi-frequency laser generation methods. The laser is input through the first fiber coupler. The horizontally polarized light after passing through the polarization beam splitting cube passes through a quarter-wave plate and then enters one of the three-frequency optical paths. After passing through the acousto-optic frequency shifter in the corresponding optical path, it is reflected by the corresponding optical path mirror. The reflected light then passes through the acousto-optic frequency shifter, quarter-wave plate, and polarization beam splitting cube in the corresponding optical path in sequence, and then is coupled into the second fiber coupler for output. Among them, by controlling the first acousto-optic frequency shifter, the second acousto-optic frequency shifter, the third acousto-optic frequency shifter, and the fourth acousto-optic frequency shifter to shift or not shift frequencies, the optical path that the laser enters and the frequency of the output laser are controlled. This scheme has the characteristics of high laser frequency purity and high suppression ratio. The three-frequency optical paths can be independently optimized, adjusted, and fixed through three mirrors, and there is no crosstalk between them. However, the above scheme does not solve the problem of poor long-term stability of the lidar.

[0005] Disclosing the information of this background art section is only intended to enhance the overall understanding of the background of this patent application, and should not be construed as an admission or any form of implication that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0006] An object of the present invention is to overcome the problem of poor stability of lidar in the prior art, and provide a fully solid-state all-weather sodium layer wind temperature detection lidar with better stability based on LD pumping technology.

[0007] To achieve the above object, the technical solution of the present invention is: a fully solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, the fully solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology includes a laser emission unit, a first telescope, a second telescope, a third telescope, a signal detection unit and a computer; The first telescope is connected to the signal detection unit through a first connecting optical fiber, the second telescope is connected to the signal detection unit through a second connecting optical fiber, the third telescope is connected to the signal detection unit through a third connecting optical fiber, the signal detection unit is connected to the computer, and the laser emission unit is connected to the computer; The laser emission unit includes a continuous light seed laser, a seed injection module, a seed injection controller, an LD end-pumped amplifier, a master laser and a slave laser. The continuous light seed laser is connected to an optical fiber splitter through a first optical fiber, the optical fiber splitter is connected to the seed injection module through a second optical fiber, the seed injection module is connected to the seed injection controller, the output end of the seed injection module is connected to the input end of the LD end-pumped amplifier, the output end of the LD end-pumped amplifier is connected to the input end of a pulsed laser sum-frequency module, and the output end of the pulsed laser sum-frequency module is connected to the input end of a laser beam expanding and splitting device; The optical fiber splitter is connected to a continuous laser sum-frequency module through a third optical fiber, and the continuous laser sum-frequency module is connected to a saturated absorption frequency stabilization device; The master laser is connected to the optical fiber splitter through a first optical fiber, the optical fiber splitter is connected to the continuous laser sum-frequency module through a second optical fiber, the optical fiber splitter is connected to a PD detector through a third optical fiber, and the PD detector is connected to an optical phase-locked loop device; The slave laser is connected to a second optical fiber splitter through a fifth optical fiber, the second optical fiber splitter is connected to a PD detector through a fourth optical fiber, the second optical fiber splitter is connected to an optical fiber amplifier through a sixth optical fiber, the optical fiber amplifier is connected to a pulse shaping device, the output end of the pulse shaping device is connected to the input end of the LD end-pumped amplifier, the LD end-pumped amplifier is connected to an LD side-pumped amplifier, and the output end of the LD side-pumped amplifier is connected to the input end of the pulsed laser sum-frequency module.

[0008] The second telescope is vertically arranged, and the first telescope and the third telescope are obliquely arranged symmetrically with respect to the second telescope.

[0009] The input end of the seed injection module is connected to the output end of the seed injection controller.

[0010] The laser beam expander and beam splitter device includes a laser beam expander, a first beam splitter, a second beam splitter and a third reflector. The input end of the laser beam expander is connected to the output end of the pulsed laser sum frequency module, and the output end of the laser beam expander is sequentially connected to the input ends of the first beam splitter, the second beam splitter and the third reflector.

[0011] The transmittance and reflectance of the first beam splitter are 70% and 30% respectively, the transmittance and reflectance of the second beam splitter are 50% and 50% respectively, and the third reflector is a total reflector. Among them, the reflected light is input into the atmosphere, and the transmitted light enters the subsequent optical path.

[0012] The signal detection unit includes a first collimator, a first atomic filter and a photon counter; The first telescope is connected to the first collimator through a first connecting optical fiber. The output end of the first collimator is connected to the input end of the first atomic filter. The output end of the first atomic filter is connected to the input end of the first focusing mirror. The output end of the first focusing mirror is connected to the input end of the first photomultiplier tube. The output end of the first photomultiplier tube is connected to the input end of the photon counter.

[0013] The signal detection unit further includes a second collimator and a second atomic filter. The second telescope is connected to the second collimator through a second connecting optical fiber. The output end of the second collimator is connected to the input end of the second atomic filter. The output end of the second atomic filter is connected to the input end of the second focusing mirror. The output end of the second focusing mirror is connected to the input end of the second photomultiplier tube. The output end of the second photomultiplier tube is connected to the input end of the photon counter.

[0014] The signal detection unit further includes a third collimator and a third atomic filter. The third telescope is connected to the third collimator through a third connecting optical fiber. The output end of the third collimator is connected to the input end of the third atomic filter. The output end of the third atomic filter is connected to the input end of the third focusing mirror. The output end of the third focusing mirror is connected to the input end of the third photomultiplier tube. The output end of the third photomultiplier tube is connected to the input end of the photon counter.

[0015] A method for using an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, the method comprising the following steps: Step 1: The laser emission unit is used to generate 589-nm single-longitudinal-mode pulsed laser, which is generated by sum-frequency mixing of pulsed lasers. The specific process is as follows: S1. First, the continuous-wave seed laser outputs single-longitudinal-mode continuous laser, which enters the fiber optic splitter through the first optical fiber and is divided into two paths. One part enters the seed injection module through the second optical fiber. Then, the seed injection module converts the continuous seed light into narrow-linewidth pulsed light and performs timing control through the seed injection controller. The narrow-linewidth pulsed light is then amplified by the LD end-pumped amplifier to generate high-power narrow-linewidth pulsed laser. The other part enters the continuous-wave laser sum-frequency mixing module through the third optical fiber, and then performs sum-frequency mixing with the continuous laser output by the master laser to generate a signal for saturated absorption frequency stabilization. S2. First, the master laser outputs single-longitudinal-mode continuous laser, which enters the fiber optic splitter through the first optical fiber and is divided into two parts. One part enters the continuous-wave laser sum-frequency mixing module through the second optical fiber and performs sum-frequency mixing with the continuous laser output by the continuous-wave seed laser to generate a signal for saturated absorption frequency stabilization. The other part enters the PD detector after laser beat frequency with the laser output by the slave laser through the third optical fiber and is converted into an electrical signal to form a beat frequency signal. S3. First, the slave laser generates continuous laser, which enters the second fiber optic splitter through the fifth optical fiber 29 and is divided into two parts. One part enters the PD detector after laser beat frequency with the laser output by the master laser through the fourth optical fiber, and then is converted into an electrical signal to form a beat frequency signal. The beat frequency signal then enters the optical phase-locked loop device to output a differential signal and transmit it to the slave laser. The other part enters the fiber optic amplifier through the sixth optical fiber, and then enters the pulse shaping device for optical chopping to form three-frequency pulsed seed light after power pre-amplification. Then, the three-frequency pulsed seed light enters the LD end-pumped amplifier and the LD side-pumped amplifier for power amplification to generate high-power narrow-linewidth three-frequency pulsed laser. S4. The above-mentioned high-power narrow-linewidth pulsed laser and high-power narrow-linewidth three-frequency pulsed laser enter the pulsed laser sum-frequency mixing module through a free optical path for pulsed laser sum-frequency mixing, so as to obtain 589-nm three-frequency pulsed laser. Step 2: The 589-nm three-frequency pulsed laser enters the atmosphere through the laser beam expander and splitter device. Step 3: The upper atmosphere and the three beams of 589-nm three-frequency pulsed laser first generate echo photons, which are then received by the first telescope, the second telescope, and the third telescope respectively. Subsequently, the first telescope, the second telescope, and the third telescope respectively input the echo photons into the signal detection unit through the first connecting optical fiber, the second connecting optical fiber, and the third connecting optical fiber. Step 4: The signal detection unit first obtains the echo signal, and then stores the echo signal in a computer for processing to obtain the results of the wind temperature and sodium atom number density of the atmospheric sodium layer.

[0016] The saturated absorption signal is input into the master laser for frequency locking.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology of the present invention, the first telescope is connected to the signal detection unit through the first optical fiber, the second telescope is connected to the signal detection unit through the second optical fiber, the third telescope is connected to the signal detection unit through the third optical fiber, the signal detection unit is connected to the computer, and the laser emission unit is connected to the computer. During application, the laser emission unit pumps the pulsed seed light to generate high-power narrow-linewidth 589-nm three-frequency pulsed laser. Based on the end-pumping technology and side-pumping technology for direct pumping, the generation of the laser does not depend on the optical resonator, which improves the switching speed of the three frequencies; the system adopts optical fiber transmission technology to ensure the stability and anti-interference ability of signal transmission; at the same time, compared with the dye laser in which the dye is dissolved in the liquid solute, the solid laser adds the working substance to the glass or crystal as doping. The solid laser has good stability, its service life is much higher than that of the dye laser, and its operation stability is higher, especially excellent in extreme environments, providing reliable technical support for the atmospheric detection in the mesosphere-lower thermosphere region. Therefore, the lidar of the present invention has better stability, faster switching speed of the three frequencies, and a flexible variable frequency switching range.

[0018] 2. In the all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology of the present invention, through the flexible modulation of the current of the seed laser by the optical phase-locked loop, the system can quickly switch to different frequencies, improving the scalability of detection. The collected laser power is high, and an echo signal with a higher signal-to-noise ratio can be obtained. The first, second, and third telescopes respectively receive the echo photons in the north, west, and vertical directions, ensuring the comprehensive collection of signals. Each component of the system is designed modularly, reducing the complexity of maintenance and management. Therefore, the laser power collected by the present invention is high, and the signal collection is more comprehensive.

[0019] 3. In the all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology of the present invention, when the all-solid-state lidar system operates in remote or field environments, the maintenance requirements are low, which is suitable for long-term unattended observation tasks. The design of the all-solid-state laser structure makes the system operate more stably in harsh environments. At the same time, due to the long service life of the all-solid-state laser, the maintenance frequency can be significantly reduced, saving the maintenance cost of the system. Therefore, the present invention can adapt to harsh environments and has low usage costs.

[0020] 4. In the all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology of the present invention, this solution supports signal acquisition during both day and night, can monitor the sodium atom density, wind field, and temperature in the MLT region all-weather. The all-solid-state laser and fiber optic receiving system operate stably in low-temperature environments, and signal acquisition is not significantly affected. The fiber optic receiving technology performs excellently in high-altitude environments, with strong practicality, adaptable to vehicle-mounted and spaceborne detection environments, providing an effective means for the popularization and application of lidar. Therefore, the present invention can be vehicle-mounted and spaceborne, making the measurement more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the present invention.

[0022] Figure 2 is a schematic structural diagram of the laser emission unit in the present invention.

[0023] Figure 3 is a schematic structural diagram of the laser beam expanding and splitting device in the present invention.

[0024] Figure 4 is a schematic structural diagram of the signal detection unit in the present invention.

[0025] Figure 5 is a flow chart of the present invention.

[0026] In the figure: laser emission unit 1, first telescope 2, second telescope 3, third telescope 4, first optical fiber 5, second optical fiber 6, third optical fiber 7, signal detection unit 8, computer 9, continuous light seed laser 10, first optical fiber 11, optical fiber splitter 12, second optical fiber 13, third optical fiber 14, seed injection module 15, seed injection controller 16, LD end-pumped amplifier 17, master laser 18, first optical fiber 19, first optical fiber splitter 20, second optical fiber 21, continuous laser sum frequency module 22, saturated absorption frequency stabilization device 23, third optical fiber 24, fourth optical fiber 25, PD detector 26, optical phase-locked loop device 27, slave laser 28, fifth optical fiber 29, second optical fiber splitter 30, sixth optical fiber 31, optical fiber amplifier 32, pulse shaping device 33, LD end-pumped amplifier 34, LD side-pumped amplifier 35, pulsed laser sum frequency module 36, laser beam expanding and splitting device 37, laser beam expander 38, first beam splitter 39, second beam splitter 40, third reflector 41, first collimator 42, second collimator 43, third collimator 44, first atomic filter 45, second atomic filter 46, third atomic filter 47, first focusing mirror 48, second focusing mirror 49, third focusing mirror 50, first photomultiplier tube 51, second photomultiplier tube 52, third photomultiplier tube 53, photon counter 54. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] See Figures 1 to 5 , see Figures 1 to 5 , an all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology, the all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology includes a laser emission unit 1, a first telescope 2, a second telescope 3, a third telescope 4, a signal detection unit 8 and a computer 9; The first telescope 2 is connected to the signal detection unit 8 through a first connecting optical fiber 5, the second telescope 3 is connected to the signal detection unit 8 through a second connecting optical fiber 6, the third telescope 4 is connected to the signal detection unit 8 through a third connecting optical fiber 7, the signal detection unit 8 is connected to the computer 9, and the laser emission unit 1 is connected to the computer 9; The laser emission unit 1 includes a continuous light seed laser 10, a seed injection module 15, a seed injection controller 16, an LD end-pumped amplifier 17, a master laser 18 and a slave laser 28. The continuous light seed laser 10 is connected to an optical fiber splitter 12 through a first optical fiber 11. The optical fiber splitter 12 is connected to the seed injection module 15 through a second optical fiber 13. The seed injection module 15 is connected to the seed injection controller 16. The output end of the seed injection module 15 is connected to the input end of the LD end-pumped amplifier 17. The output end of the LD end-pumped amplifier 17 is connected to the input end of a pulsed laser sum-frequency module 36. The output end of the pulsed laser sum-frequency module 36 is connected to the input end of a laser beam expansion and splitting device 37; The optical fiber splitter 12 is connected to a continuous laser sum-frequency module 22 through a third optical fiber 14. The continuous laser sum-frequency module 22 is connected to a saturated absorption frequency stabilization device 23; The master laser 18 is connected to an optical fiber splitter 20 through a first optical fiber 19. The optical fiber splitter 20 is connected to the continuous laser sum-frequency module 22 through a second optical fiber 21. The optical fiber splitter 20 is connected to a PD detector 26 through a third optical fiber 24. The PD detector 26 is connected to an optical phase-locked loop device 27; The slave laser 28 is connected to a second optical fiber splitter 30 through a fifth optical fiber 29. The second optical fiber splitter 30 is connected to the PD detector 26 through a fourth optical fiber 25. The second optical fiber splitter 30 is connected to an optical fiber amplifier 32 through a sixth optical fiber 31. The optical fiber amplifier 32 is connected to a pulse shaping device 33. The output end of the pulse shaping device 33 is connected to the input end of the LD end-pumped amplifier 34. The output end of the LD end-pumped amplifier 34 is connected to the input end of the LD side-pumped amplifier 35. The output end of the LD side-pumped amplifier 35 is connected to the input end of the pulsed laser sum-frequency module 36.

[0029] The second telescope 3 is vertically arranged, and the first telescope 2 and the third telescope 4 are obliquely arranged.

[0030] The input end of the seed injection module 15 is connected to the output end of the seed injection controller 16.

[0031] The laser beam expander and beam splitter device 37 includes a laser beam expander 38, a first beam splitter 39, a second beam splitter 40 and a third reflector 41. The input end of the laser beam expander 38 is connected to the output end of the pulsed laser sum frequency module 36, and the output end of the laser beam expander 38 is sequentially connected to the input ends of the first beam splitter 39, the second beam splitter 40 and the third reflector 41.

[0032] The transmittance and reflectance of the first beam splitter 39 are 70% and 30% respectively, the transmittance and reflectance of the second beam splitter are 50% and 50% respectively, and the third reflector 41 is a total reflector. Among them, the reflected light is input into the atmosphere, and the transmitted light enters the subsequent optical path.

[0033] The signal detection unit 8 includes a first collimator 42, a first atomic filter 45 and a photon counter 54; The first telescope 2 is connected to the first collimator 42 through a first connecting optical fiber 5. The output end of the first collimator 42 is connected to the input end of the first atomic filter 45. The output end of the first atomic filter 45 is connected to the input end of the first focusing mirror 48. The output end of the first focusing mirror 48 is connected to the input end of the first photomultiplier tube 51. The output end of the first photomultiplier tube 51 is connected to the input end of the photon counter 54.

[0034] The signal detection unit 8 further includes a second collimator 43 and a second atomic filter 46. The second telescope 3 is connected to the second collimator 43 through a second connecting optical fiber 6. The output end of the second collimator 43 is connected to the input end of the second atomic filter 46. The output end of the second atomic filter 46 is connected to the input end of the second focusing mirror 49. The output end of the second focusing mirror 49 is connected to the input end of the second photomultiplier tube 52. The output end of the second photomultiplier tube 52 is connected to the input end of the photon counter 54.

[0035] The signal detection unit 8 further includes a third collimator 44 and a third atomic filter 47. The third telescope 4 is connected to the third collimator 44 through a third connecting optical fiber 7. The output end of the third collimator 44 is connected to the input end of the third atomic filter 47. The output end of the third atomic filter 47 is connected to the input end of the third focusing mirror 50. The output end of the third focusing mirror 50 is connected to the input end of the third photomultiplier tube 53. The output end of the third photomultiplier tube 53 is connected to the input end of the photon counter 54.

[0036] A method for using an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, the method comprising the following steps: First step: The laser emission unit 1 is used to generate 589 nm single-longitudinal-mode pulsed laser, and the 589 nm single-longitudinal-mode pulsed laser is generated by sum-frequency mixing of pulsed laser and pulsed laser. The specific process is as follows: S1: First, the continuous-wave seed laser 10 outputs single-longitudinal-mode continuous laser, and this laser enters the fiber optic splitter 12 through the first optical fiber 11 and is divided into two paths. One part enters the seed injection module 15 through the second optical fiber 13; then the seed injection module 15 converts the continuous seed light into narrow-linewidth pulsed light and performs timing control through the seed injection controller 16. The narrow-linewidth pulsed light is then amplified by the LD end-pumped amplifier 17 to generate high-power narrow-linewidth pulsed laser; the other part enters the continuous-wave laser sum-frequency mixing module 22 through the third optical fiber 14, and then performs sum-frequency mixing with the continuous laser output by the master laser 18 to generate a signal for saturated absorption frequency stabilization. S2: First, the master laser 18 outputs single-longitudinal-mode continuous laser, and this laser enters the fiber optic splitter 20 through the first optical fiber 19 and is divided into two parts. One part enters the continuous-wave laser sum-frequency mixing module 22 through the second optical fiber 21 to perform sum-frequency mixing with the continuous laser output by the continuous-wave seed laser 11 to generate a signal for saturated absorption frequency stabilization; the other part enters the PD detector 26 through the third optical fiber 24 after laser beat frequency with the laser output by the slave laser 28 and is converted into an electrical signal to form a beat frequency signal. S3: First, the slave laser 28 generates continuous laser, and this laser is input into the second fiber optic splitter 30 through the fifth optical fiber 29 and is divided into two parts. One part enters the PD detector 26 through the fourth optical fiber 25 after laser beat frequency with the laser output by the master laser 18, and then is converted into an electrical signal to form a beat frequency signal. The beat frequency signal then enters the optical phase-locked loop device 27 and outputs a differential signal to be transmitted to the slave laser 28; the other part is input into the fiber optic amplifier 32 through the sixth optical fiber 31, and after power pre-amplification, enters the pulse shaping device 33 for optical chopping to form pulsed three-frequency pulsed seed light. Then the three-frequency pulsed seed light enters the LD end-pumped amplifier 34 and the LD side-pumped amplifier 35 for power amplification to generate high-power narrow-linewidth three-frequency pulsed laser. S4: The above-mentioned high-power narrow-linewidth pulsed laser and high-power narrow-linewidth three-frequency pulsed laser enter the pulsed laser sum-frequency mixing module 36 through a free optical path for pulsed laser sum-frequency mixing, thereby obtaining 589 nm three-frequency pulsed laser. Second step: The 589 nm three-frequency pulsed laser enters the atmosphere through the laser beam expander and splitter device 37. Step 3: The upper atmosphere and the three 589-nm three-frequency pulsed lasers first generate echo photons, which are then received by the first telescope 2, the second telescope 3, and the third telescope 4 respectively. Subsequently, the first telescope 2, the second telescope 3, and the third telescope 4 respectively input the echo photons into the signal detection unit 8 by using the first connecting optical fiber 5, the second connecting optical fiber 6, and the third connecting optical fiber 7; Step 4: The signal detection unit 8 first obtains the echo signal, and then stores the echo signal in the computer 9 for processing to obtain the results of the air temperature and sodium atom number density of the atmospheric sodium layer.

[0037] The saturated absorption signal is input into the master laser 18 for frequency locking.

[0038] The supplementary description of the present invention is as follows: The 589-nm three-frequency pulsed laser generation scheme of the invention uses a 1319-nm LD end-pumped amplifier, a 1064-nm LD end-pumped amplifier, and a 1064-nm LD side-pumped amplifier to directly amplify the seed laser after saturated absorption frequency stabilization and three-frequency switching.

[0039] Embodiment 1: An all-solid-state all-day sodium layer air temperature detection lidar based on LD pumping technology, the all-solid-state all-day sodium layer air temperature detection lidar based on LD pumping technology includes a laser emission unit 1, a first telescope 2, a second telescope 3, a third telescope 4, a signal detection unit 8, and a computer 9; The first telescope 2 is connected to the signal detection unit 8 through the first 589-nm optical fiber 5, the second telescope 3 is connected to the signal detection unit 8 through the second 589-nm optical fiber 6, the third telescope 4 is connected to the signal detection unit 8 through the third 589-nm optical fiber 7, the signal detection unit 8 is connected to the computer 9, and the laser emission unit 1 is connected to the computer 9; The frequency switching of the 589-nm single-longitudinal-mode pulsed laser is achieved by switching the 1064-nm pulsed laser through an optical phase-locked loop technology. According to the laser sum-frequency formula, when the 1064-nm laser generates a frequency shift of ±630 MHz, the corresponding 589-nm laser will also generate a frequency shift of ±630 MHz. The frequency stabilization of the 589-nm laser is achieved by saturated absorption frequency stabilization; The laser emission unit 1 includes a 1319 nm continuous light seed laser 10, a 1319 nm seed injection module 15, a seed injection controller 16, an LD end-pumped amplifier 17, and a 1064 nm master laser 18. The 1319 nm continuous light seed laser 10 is connected to a 1319 nm fiber splitter 12 through a first 1319 nm optical fiber 11. The 1319 nm fiber splitter 12 is connected to the 1319 nm seed injection module 15 through a second 1319 nm optical fiber 13. The 1319 nm seed injection module is used to convert the 1319 nm continuous seed light in the mW level into narrow linewidth pulsed light. The 1319 nm seed injection module 15 is connected to the seed injection controller 16. The seed injection controller 16 generates a Q-switching trigger at a certain moment to achieve timing control. The output end of the seed injection module 15 is connected to the input end of the LD end-pumped amplifier 17. The output end of the LD end-pumped amplifier 17 is connected to the input end of the pulsed laser sum-frequency module 36. The output end of the pulsed laser sum-frequency module 36 is connected to the input end of the laser beam expander and splitter device 37; The 1319 nm fiber splitter 12 is connected to the continuous laser sum-frequency module 22 through a third 1319 nm optical fiber 14. The continuous laser sum-frequency module 22 is connected to the saturated absorption frequency stabilization device 23; The 1064 nm master laser 18 is connected to a 1064 nm fiber splitter 20 through a first 1064 nm optical fiber 19. The 1064 nm fiber splitter 20 is connected to the continuous laser sum-frequency module 22 through a second 1064 nm optical fiber 21. The 1064 nm fiber splitter 20 is connected to a PD detector 26 through a third 1064 nm optical fiber 24. The PD detector 26 is connected to the optical phase-locked loop device 27; The 1064 nm slave laser 28 is connected to a second 1064 nm fiber splitter 30 through a fifth 1064 nm optical fiber 29. The second 1064 nm fiber splitter 30 is connected to the PD detector 26 through a fourth 1064 nm optical fiber 25. The second 1064 nm fiber splitter 30 is connected to an optical fiber amplifier 32 through a sixth 1064 nm optical fiber 31. The optical fiber amplifier 32 is connected to a pulse shaping device 33. The output end of the pulse shaping device 33 is connected to the input end of the 1064 nm LD end-pumped amplifier 34. The output end of the 1064 nm LD end-pumped amplifier 34 is connected to the input end of the 1064 nm LD side-pumped amplifier 35. The output end of the 1064 nm LD side-pumped amplifier 35 is connected to the input end of the pulsed laser sum-frequency module 36; A method for using an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, the method comprising the following steps: Step 1: The laser emission unit 1 is used to generate 589-nm single-longitudinal-mode pulsed laser, which is generated by sum-frequency mixing of 1319-nm pulsed laser and 1064-nm pulsed laser. The specific process is as follows: S1: First, the 1319-nm continuous-wave seed laser 10 outputs single-longitudinal-mode 1319-nm continuous laser, which enters the 1319-nm fiber optical splitter 12 through the first 1319-nm optical fiber 11 and is divided into two paths. One part enters the 1319-nm seed injection module 15 through the second 1319-nm optical fiber 13. Then, the 1319-nm seed injection module 15 converts the continuous seed light into narrow-linewidth pulsed light and performs timing control through the seed injection controller 16. The narrow-linewidth pulsed light is then amplified by the 1319-nm LD end-pumped amplifier 17 to generate 1319-nm high-power narrow-linewidth pulsed laser. The other part enters the continuous laser sum-frequency mixing module 22 through the third 1319-nm optical fiber 14, and then performs sum-frequency mixing with the 1064-nm continuous laser output by the 1064-nm master laser 18 to generate a signal for saturated absorption frequency stabilization. S2: First, the 1064-nm master laser 18 outputs single-longitudinal-mode 1064-nm continuous laser, which enters the 1064-nm fiber optical splitter 20 through the first 1064-nm optical fiber 19 and is divided into two parts. One part enters the continuous laser sum-frequency mixing module 22 through the second 1064-nm optical fiber 21 to perform sum-frequency mixing with the 1319-nm continuous laser output by the 1319-nm continuous-wave seed laser 11 to generate a signal for saturated absorption frequency stabilization. The other part enters the PD detector 26 after laser beat frequency with the laser output by the 1064-nm slave laser 28 through the third 1064-nm optical fiber 24 and is converted into an electrical signal to form a beat frequency signal. S3: First, the 1064-nm slave laser 28 generates 1064-nm continuous laser, which enters the second 1064-nm fiber optical splitter 30 through the fifth 1064-nm optical fiber 29 and is divided into two parts. One part enters the PD detector 26 after laser beat frequency with the laser output by the 1064-nm master laser 18 through the fourth 1064-nm optical fiber 25, and then is converted into an electrical signal to form a beat frequency signal. The beat frequency signal then enters the optical phase-locked loop device 27 to output a differential signal and transmit it to the 1064-nm slave laser 28. The other part enters the fiber optical amplifier 32 through the sixth 1064-nm optical fiber 31, and after power pre-amplification, enters the pulse shaping device 33 for optical chopping to form pulsed 1064-nm three-frequency pulsed seed light. Then, the 1064-nm three-frequency pulsed seed light enters the 1064-nm LD end-pumped amplifier 34 and the 1064-nm LD side-pumped amplifier 35 for power amplification to generate 1064-nm high-power narrow-linewidth three-frequency pulsed laser. S4. The above-mentioned 1319 nm high-power narrow-linewidth pulsed laser and 1064 nm high-power narrow-linewidth three-frequency pulsed laser enter the pulsed laser sum-frequency module 36 through a free optical path for pulsed laser sum-frequency, thereby obtaining a 589 nm three-frequency pulsed laser; Step 2. The 589 nm three-frequency pulsed laser enters the atmosphere through the laser beam expander and beam splitter device 37; Step 3. The upper atmosphere and the three beams of 589 nm three-frequency pulsed lasers first generate echo photons, and then are respectively received by the first telescope 2, the second telescope 3, and the third telescope 4. Subsequently, the first telescope 2, the second telescope 3, and the third telescope 4 respectively use the first 589 nm optical fiber 5, the second 589 nm optical fiber 6, and the third 589 nm optical fiber 7 to input the echo photons into the signal detection unit 8; Step 4. The signal detection unit 8 first obtains an echo signal, and then stores the echo signal in the computer 9 for processing to obtain the results of the air sodium layer wind temperature and sodium atom number density.

[0040] Embodiment 2: Embodiment 2 is basically the same as Embodiment 1, and the difference lies in: The laser beam expander and beam splitter device 37 includes a laser beam expander 38, a first beam splitter 39, a second beam splitter 40, and a third reflector 41. The input end of the laser beam expander 38 is connected to the output end of the pulsed laser sum-frequency module 36, and the output end of the laser beam expander 38 is respectively connected to the input ends of the first beam splitter 39, the second beam splitter 40, and the third reflector 41; the transmittance and reflectance of the first beam splitter 39 are 70% and 30% respectively, the transmittance and reflectance of the second beam splitter are 50% and 50% respectively, and the third reflector 41 is a total reflector. Among them, the reflected light is input into the atmosphere, and the transmitted light enters the subsequent optical path.

[0041] During application: The 589 nm three-frequency pulsed laser is expanded and collimated by the laser beam expander 38. After passing through the first beam splitter 39, the laser is divided into two parts. One part reaches the second beam splitter 40, and the other part is emitted into the atmosphere in the north direction; the remaining laser is divided into two parts after reaching the second beam splitter 41. One part enters the third reflector and is emitted into the atmosphere in the west direction, and the other part is emitted into the atmosphere in the vertical direction. After the air sodium layer and the three beams of 589 nm three-frequency pulsed lasers generate echo photons, they can be respectively received by the first telescope 2, the second telescope 3, and the third telescope 4. Subsequently, the first telescope 2, the second telescope 3, and the third telescope 4 respectively use the first 589 nm optical fiber 5, the second 589 nm optical fiber 6, and the third 589 nm optical fiber 7 to input the echo photons into the signal detection unit 8.

[0042] Embodiment 3: Example 3 is basically the same as Example 1, except that: The signal detection unit 8 includes a first collimator 42, a first atomic filter 45 and a photon counter 54; the first telescope 2 is connected to the first collimator 42 through a first 589 nm optical fiber 5, the output end of the first collimator 42 is connected to the input end of the first atomic filter 45, the output end of the first atomic filter 45 is connected to the input end of the first focusing mirror 48, the output end of the first focusing mirror 48 is connected to the input end of the first photomultiplier tube 51, and the output end of the first photomultiplier tube 51 is connected to the input end of the photon counter 54; the signal detection unit 8 further includes a second collimator 43 and a second atomic filter 46, the second telescope 3 is connected to the second collimator 43 through a second 589 nm optical fiber 6, the output end of the second collimator 43 is connected to the input end of the second atomic filter 46, the output end of the second atomic filter 46 is connected to the input end of the second focusing mirror 49, the output end of the second focusing mirror 49 is connected to the input end of the second photomultiplier tube 52, and the output end of the second photomultiplier tube 52 is connected to the input end of the photon counter 54; the signal detection unit 8 further includes a third collimator 44 and a third atomic filter 47, the third telescope 4 is connected to the third collimator 44 through a third 589 nm optical fiber 7, the output end of the third collimator 44 is connected to the input end of the third atomic filter 47, the output end of the third atomic filter 47 is connected to the input end of the third focusing mirror 50, the output end of the third focusing mirror 50 is connected to the input end of the third photomultiplier tube 53, and the output end of the third photomultiplier tube 53 is connected to the input end of the photon counter 54.

[0043] During application: During the day, the first 589-nm optical fiber 5, the second 589-nm optical fiber 6, and the third 589-nm optical fiber 7 input echo photons into the first collimator 42, the second collimator 43, and the third collimator 44 respectively. After collimation, they enter the first atomic filter 45, the second atomic filter 46, and the third atomic filter 47 respectively to filter out stray light and background light. Subsequently, after being focused by the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50, they enter the first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 respectively. The first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 convert the optical signal into an electrical signal. Subsequently, a photon counter 54 is used for data acquisition to obtain a photon signal, and the collected photon signal is stored in a computer 9 for processing to obtain the results of the air sodium layer wind temperature and sodium atom number density. During the night, the first 589-nm optical fiber 5, the second 589-nm optical fiber 6, and the third 589-nm optical fiber 7 input echo photons into the first collimator 42, the second collimator 43, and the third collimator 44 respectively. After collimation, they enter the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50 respectively. After being focused by the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50, they enter the first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 respectively. The first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 convert the optical signal into an electrical signal. Subsequently, a photon counter 54 is used for data acquisition to obtain a photon signal, and the collected photon signal is stored in a computer 9 for processing to obtain the results of the air sodium layer wind temperature and sodium atom number density.

[0044] Example 4: Example 4 is basically the same as Example 1, and the difference lies in: A method for using an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, the method comprising the following steps: The first step, the laser emission unit 1 is used to generate 589-nm single-longitudinal-mode pulsed laser, and the 589-nm single-longitudinal-mode pulsed laser is generated by sum-frequency mixing of 1319-nm pulsed laser and 1064-nm pulsed laser. The specific process is as follows: S1. First, the 1319 nm continuous-wave seed laser 10 outputs single-longitudinal-mode 1319 nm continuous laser. This laser enters the 1319 nm fiber splitter 12 through the first 1319 nm fiber 11 and is divided into two paths. One part enters the 1319 nm seed injection module 15 through the second 1319 nm fiber 13. Then, the 1319 nm seed injection module 15 converts the continuous seed light into narrow-linewidth pulsed light and performs timing control through the seed injection controller 16. The narrow-linewidth pulsed light is then amplified by the 1319 nm LD end-pumped amplifier 17 to generate 1319 nm high-power narrow-linewidth pulsed laser. The other part enters the continuous-wave laser sum-frequency module 22 through the third 1319 nm fiber 14, and then sum-frequencies with the 1064 nm continuous laser output by the 1064 nm master laser 18 to generate a signal for saturated absorption frequency stabilization. The saturated absorption signal is input to the 1064 nm master laser 18 for frequency locking. S2. First, the 1064 nm master laser 18 outputs single-longitudinal-mode 1064 nm continuous laser. This laser enters the 1064 nm fiber splitter 20 through the first 1064 nm fiber 19 and is divided into two parts. One part enters the continuous-wave laser sum-frequency module 22 through the second 1064 nm fiber 21 and sum-frequencies with the 1319 nm continuous laser output by the 1319 nm continuous-wave seed laser 11 to generate a signal for saturated absorption frequency stabilization. The saturated absorption signal is input to the 1064 nm master laser 18 for frequency locking. The other part enters the PD detector 26 after laser beat frequency with the laser output by the 1064 nm slave laser 28 through the third 1064 nm fiber 24 and is converted into an electrical signal to form a beat frequency signal. S3. First, the 1064 nm slave laser 28 generates 1064 nm continuous laser. This laser is input to the second 1064 nm fiber splitter 30 through the fifth 1064 nm fiber 29 and is divided into two parts. One part enters the PD detector 26 after laser beat frequency with the laser output by the 1064 nm master laser 18 through the fourth 1064 nm fiber 25, and then is converted into an electrical signal to form a beat frequency signal. The beat frequency signal then enters the optical phase-locked loop device 27 and outputs a differential signal to the 1064 nm slave laser 28 for laser frequency switching. The beat frequency signal then enters the optical phase-locked loop device 27 and outputs a differential signal to the 1064 nm slave laser 28. The other part is input to the fiber amplifier 32 through the sixth 1064 nm fiber 31, and after power pre-amplification, enters the pulse shaping device 33 for optical chopping to form pulsed 1064 nm three-frequency pulsed seed light. Then, the 1064 nm three-frequency pulsed seed light enters the 1064 nm LD end-pumped amplifier 34 and the 1064 nm LD side-pumped amplifier 35 for power amplification to generate 1064 nm high-power narrow-linewidth three-frequency pulsed laser. S4. The above-mentioned 1319 nm high-power narrow-linewidth pulsed laser and 1064 nm high-power narrow-linewidth triple-frequency pulsed laser enter the pulsed laser sum-frequency module 36 through a free optical path for pulsed laser sum-frequency, thereby obtaining a 589 nm triple-frequency pulsed laser; Second step: The 589 nm triple-frequency pulsed laser enters the atmosphere through the laser beam expander and beam splitter device 37; Third step: The atmospheric sodium layer first generates echo photons with the three beams of 589 nm triple-frequency pulsed lasers, and then the echo photons are respectively received by the first telescope 2, the second telescope 3, and the third telescope 4. Subsequently, the first telescope 2, the second telescope 3, and the third telescope 4 respectively input the echo photons into the signal detection unit 8 by using the first 589 nm optical fiber 5, the second 589 nm optical fiber 6, and the third 589 nm optical fiber 7; Fourth step: The signal detection unit 8 first obtains a photon signal, and then stores the photon signal in the computer 9 for processing to obtain the results of the wind temperature and sodium atom number density of the atmospheric sodium layer; The signal detection unit 8 first obtains a photon signal, and then stores the photon signal in the computer 9 for processing to obtain the results of the wind temperature and sodium atom number density of the atmospheric sodium layer specifically as follows: During the day, the first 589 nm optical fiber 5, the second 589 nm optical fiber 6, and the third 589 nm optical fiber 7 respectively input the echo photons into the first collimating mirror 42, the second collimating mirror 43, and the third collimating mirror 44. After collimation, they respectively enter the first atomic filter 45, the second atomic filter 46, and the third atomic filter 47 to filter out stray light and background light. Subsequently, after being focused by the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50, they respectively enter the first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53. The first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 convert the optical signal into an electrical signal, and then the photon counter 54 is used for data acquisition to obtain a photon signal. The collected photon signal is stored in the computer 9 for processing to obtain the results of the wind temperature and sodium atom number density of the atmospheric sodium layer; During the night, the first 589 nm optical fiber 5, the second 589 nm optical fiber 6, and the third 589 nm optical fiber 7 respectively input the echo photons into the first collimating mirror 42, the second collimating mirror 43, and the third collimating mirror 44. After collimation, they respectively enter the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50. After being focused by the first focusing mirror 48, the second focusing mirror 49, and the third focusing mirror 50, they respectively enter the first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53. The first photomultiplier tube 51, the second photomultiplier tube 52, and the third photomultiplier tube 53 convert the optical signal into an electrical signal, and then the photon counter 54 is used for data acquisition to obtain a photon signal. The collected photon signal is stored in the computer 9 for processing to obtain the results of the wind temperature and sodium atom number density of the atmospheric sodium layer.

[0045] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those of ordinary skill in the art according to the disclosure of the present invention shall fall within the protection scope recorded in the claims.

Claims

1. An all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology, characterized in that: The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology includes a laser emission unit (1), a first telescope (2), a second telescope (3), a third telescope (4), a signal detection unit (8) and a computer (9); The first telescope (2) is connected to the signal detection unit (8) through a first connecting optical fiber (5), the second telescope (3) is connected to the signal detection unit (8) through a second connecting optical fiber (6), the third telescope (4) is connected to the signal detection unit (8) through a third connecting optical fiber (7), the signal detection unit (8) is connected to the computer (9), and the laser emission unit (1) is connected to the computer (9); The laser emission unit (1) includes a continuous light seed laser (10), a seed injection module (15), a seed injection controller (16), an LD end-pumped amplifier (17), a master laser (18) and a slave laser (28). The continuous light seed laser (10) is connected to an optical fiber splitter (12) through a first optical fiber (11), the optical fiber splitter (12) is connected to the seed injection module (15) through a second optical fiber (13), the seed injection module (15) is connected to the seed injection controller (16), the output end of the seed injection module (15) is connected to the input end of the LD end-pumped amplifier (17), the output end of the LD end-pumped amplifier (17) is connected to the input end of a pulsed laser sum-frequency module (36), and the output end of the pulsed laser sum-frequency module (36) is connected to the input end of a laser beam expanding and splitting device (37); The optical fiber splitter (12) is connected to a continuous laser sum-frequency module (22) through a third optical fiber (14), and the continuous laser sum-frequency module (22) is connected to a saturated absorption frequency stabilization device (23); The master laser (18) is connected to an optical fiber splitter (20) through a first optical fiber (19), the optical fiber splitter (20) is connected to the continuous laser sum-frequency module (22) through a second optical fiber (21), the optical fiber splitter (20) is connected to a PD detector (26) through a third optical fiber (24), and the PD detector (26) is connected to an optical phase-locked loop device (27); The slave laser (28) is connected to a second optical fiber splitter (30) through a fifth optical fiber (29), the second optical fiber splitter (30) is connected to the PD detector (26) through a fourth optical fiber (25), the second optical fiber splitter (30) is connected to an optical fiber amplifier (32) through a sixth optical fiber (31), the optical fiber amplifier (32) is connected to a pulse shaping device (33), the output end of the pulse shaping device (33) is connected to the input end of the LD end-pumped amplifier (34), the LD end-pumped amplifier (34) is connected to an LD side-pumped amplifier (35), and the output end of the LD side-pumped amplifier (35) is connected to the input end of the pulsed laser sum-frequency module (36).

2. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 1, characterized in that: The second telescope (3) is vertically arranged, and the first telescope (2) and the third telescope (4) are obliquely arranged with the second telescope (3) as the reference.

3. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 1, characterized in that: The input end of the seed injection module (15) is connected to the output end of the seed injection controller (16).

4. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 1, wherein: The laser beam expanding and splitting device (37) includes a laser beam expander (38), a first beam splitter (39), a second beam splitter (40) and a third reflector (41). The input end of the laser beam expander (38) is connected to the output end of the pulsed laser sum frequency module (36), and the output end of the laser beam expander (38) is sequentially connected to the input ends of the first beam splitter (39), the second beam splitter (40) and the third reflector (41).

5. The all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology according to claim 4, characterized in that: The transmittance and reflectance of the first beam splitter (39) are 70% and 30% respectively, the transmittance and reflectance of the second beam splitter (40) are 50% and 50% respectively, and the third reflector (41) is a total reflector. Among them, the reflected light is input into the atmosphere, and the transmitted light enters the subsequent optical path.

6. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 1, characterized in that: The signal detection unit (8) includes a first collimator (42), a first atomic filter (45) and a photon counter (54); The first telescope (2) is connected to the first collimator (42) through a first connecting optical fiber (5). The output end of the first collimator (42) is connected to the input end of the first atomic filter (45). The output end of the first atomic filter (45) is connected to the input end of the first focusing mirror (48). The output end of the first focusing mirror (48) is connected to the input end of the first photomultiplier tube (51). The output end of the first photomultiplier tube (51) is connected to the input end of the photon counter (54).

7. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 6, characterized in that: The signal detection unit (8) further includes a second collimator (43) and a second atomic filter (46). The second telescope (3) is connected to the second collimator (43) through a second connecting optical fiber (6). The output end of the second collimator (43) is connected to the input end of the second atomic filter (46). The output end of the second atomic filter (46) is connected to the input end of the second focusing mirror (49). The output end of the second focusing mirror (49) is connected to the input end of the second photomultiplier tube (52). The output end of the second photomultiplier tube (52) is connected to the input end of the photon counter (54).

8. The all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 7, characterized in that: The signal detection unit (8) further includes a third collimator (44) and a third atomic filter (47). The third telescope (4) is connected to the third collimator (44) through a third connecting optical fiber (7). The output end of the third collimator (44) is connected to the input end of the third atomic filter (47). The output end of the third atomic filter (47) is connected to the input end of the third focusing mirror (50). The output end of the third focusing mirror (50) is connected to the input end of the third photomultiplier tube (53). The output end of the third photomultiplier tube (53) is connected to the input end of the photon counter (54).

9. A method for using an all-solid-state all-day sodium layer wind temperature detection lidar based on LD pumping technology according to claim 1, characterized in that: The usage method includes the following steps: First step, the laser emitting unit (1) is used to generate 589 nm single longitudinal mode pulsed laser, and the 589 nm single longitudinal mode pulsed laser is generated by the pulsed laser and pulsed laser sum frequency. The specific process is as follows: S1. First, the continuous-wave (CW) seed laser (10) outputs single-longitudinal-mode CW laser. This laser enters the fiber optic splitter (12) through the first optical fiber (11) and is split into two paths. One part enters the seed injection module (15) through the second optical fiber (13). Then, the seed injection module (15) converts the CW seed light into narrow-linewidth pulsed light and performs timing control through the seed injection controller (16). The narrow-linewidth pulsed light is amplified by the LD end-pumped amplifier (17) to generate high-power narrow-linewidth pulsed laser. The other part enters the CW laser sum-frequency module (22) through the third optical fiber (14), and then sum-frequencies with the CW laser output by the master laser (18) to generate a signal for saturated absorption frequency stabilization. S2. First, the master laser (18) outputs single-longitudinal-mode CW laser. This laser enters the fiber optic splitter (20) through the first optical fiber (19) and is split into two parts. One part enters the CW laser sum-frequency module (22) through the second optical fiber (21) and sum-frequencies with the CW laser output by the CW seed laser (11) to generate a signal for saturated absorption frequency stabilization. The other part enters the PD detector (26) after laser beat frequency with the laser output by the slave laser (28) through the third optical fiber (24), and is converted into an electrical signal to form a beat frequency signal. S3. First, the slave laser (28) generates CW laser. This laser enters the second fiber optic splitter (30) through the fifth optical fiber (29) and is split into two parts. One part enters the PD detector (26) after laser beat frequency with the laser output by the master laser (18) through the fourth optical fiber (25), and is then converted into an electrical signal to form a beat frequency signal. The beat frequency signal then enters the optical phase-locked loop device (27) and outputs a differential signal to the slave laser (28). The other part enters the fiber optic amplifier (32) through the sixth optical fiber (31), and after power pre-amplification, enters the pulse shaping device (33) for optical chopping to form three-frequency pulsed seed light. Then, the three-frequency pulsed seed light enters the LD end-pumped amplifier (34) and the LD side-pumped amplifier (35) for power amplification to generate high-power narrow-linewidth three-frequency pulsed laser. S4. The above-mentioned high-power narrow-linewidth pulsed laser and high-power narrow-linewidth three-frequency pulsed laser enter the pulsed laser sum-frequency module (36) through a free optical path for pulsed laser sum-frequency to obtain 589-nm three-frequency pulsed laser. Second step: The 589-nm three-frequency pulsed laser enters the atmosphere through the laser beam expander and splitter device (37). Third step: The high-altitude atmosphere first generates echo photons with the three beams of 589-nm three-frequency pulsed laser, and then the echo photons are received by the first telescope (2), the second telescope (3), and the third telescope (4) respectively. Subsequently, the first telescope (2), the second telescope (3), and the third telescope (4) input the echo photons into the signal detection unit (8) through the first connecting optical fiber (5), the second connecting optical fiber (6), and the third connecting optical fiber (7) respectively. Step 4: The signal detection unit (8) first obtains the echo signal and then stores the echo signal in the computer (9) for processing to obtain the results of the air sodium layer wind temperature and sodium atom number density.

10. The method for using an all-solid-state all-weather sodium layer wind temperature detection lidar based on LD pumping technology according to claim 9, characterized in that: The saturated absorption signal is input into the master laser (18) for frequency locking.

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