A signal receiving device for ozone lidar

Abstract

A signal receiving device for ozone laser radar, comprising: an optical signal processing assembly adapted to obtain n sub-backwave signals from a received backwave signal; a single-photon detector comprising n detection units, each detection unit adapted to one-to-one single-photon detection of a sub-backwave signal of one wavelength, the detection unit comprising: a silicon carbide single-photon avalanche photodiode, when the silicon carbide single-photon avalanche photodiode in a standby detection state receives a single-photon signal, the silicon carbide single-photon avalanche photodiode generates an avalanche, and an avalanche current signal is generated; an active quenching module adapted to quench the avalanche to restore the silicon carbide single-photon avalanche photodiode to the standby detection state; and a data processing assembly adapted to obtain spatial distribution data of signal intensity of n wavelength components with height according to all single-photon signals detected by the single-photon detector.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ozone detection, and particularly relates to a signal receiving device for an ozone laser radar. BACKGROUND

[0002] Ozone is an important component of the atmosphere, and the ozone layer in the atmospheric stratosphere can absorb ultraviolet components in sunlight to prevent these radiations from causing damage to the skin, eyes and immune system. Ozone in the troposphere is usually formed by photochemical reactions and is a harmful atmospheric pollutant. It can harm human health by stimulating the respiratory system and damaging lung function, and also inhibits plant growth and affects agricultural production. Therefore, monitoring the concentration of tropospheric ozone is crucial for the environment and public health. Differential absorption laser radar has the advantages of high spatial resolution, high measurement accuracy, real-time speed and large dynamic range, and has been widely used in the field of near-surface ozone detection.

[0003] Most ozone laser radars work in the ultraviolet band. Due to the scattering and absorption of the atmosphere, the ultraviolet light signal emitted by the radar will decay exponentially with the increase of the propagation distance. Therefore, such radars have extremely high requirements for the detection sensitivity of weak ultraviolet light. Single-photon detectors can detect weak light at the single-photon level and have quantum-limited sensitivity, which is beneficial to improve the detection distance and accuracy of ozone laser radars. The main method to realize single-photon detection in the ultraviolet band is to use a photomultiplier tube. However, this device has inherent disadvantages such as short service life, magnetic field sensitivity and the need for vacuum working conditions. SUMMARY

[0004] Therefore, the present application provides a signal receiving device for an ozone laser radar, comprising:

[0005] The light signal processing assembly is adapted to obtain n sub-backwave signals from the received backwave signals. Each sub-backwave signal includes a plurality of single-photon signals. The backwave signal includes n wavelength components, which are obtained after n ultraviolet laser pulse signals of different wavelengths interact with ozone in the atmosphere. The n ultraviolet laser pulse signals of different wavelengths are emitted by the emission device of the ozone laser radar. The backwave signal carries ozone information in the atmosphere. The n sub-backwave signals and the n ultraviolet laser pulse signals correspond one-to-one in wavelength, and n≥2.

[0006] The single-photon detector is coupled to the light signal processing assembly. The single-photon detector includes n detection units. Each detection unit is adapted to one-to-one single-photon detection of a sub-backwave signal of a wavelength. The detection unit includes:

[0007] The silicon carbide single-photon avalanche photodiode generates an avalanche and generates an avalanche current signal when a single-photon signal is received by the avalanche photodiode in a state of being ready to be detected.

[0008] The active quenching module is suitable for quenching the avalanche to restore the silicon carbide single-photon avalanche photodiode to the state of being ready to be detected, so as to continue to detect other single-photon signals, and is suitable for converting the avalanche current signal into a digital trigger signal output to complete the detection of the single photon.

[0009] The data processing component is suitable for obtaining spatial distribution data of signal intensities of n wavelength components with respect to height based on all single-photon signals detected by the single-photon detector, and the spatial distribution data of the signal intensities of the n wavelength components with respect to height are used to obtain ozone concentration information in the atmosphere.

[0010] According to an embodiment of the present application, the active quenching module comprises:

[0011] The extraction resistor has a first end connected to the cathode of the silicon carbide single-photon avalanche photodiode, and is used to convert the avalanche current signal into a pulse voltage signal.

[0012] The coupling capacitor has a first end connected to the cathode of the silicon carbide single-photon avalanche photodiode, and is suitable for coupling the pulse voltage signal.

[0013] The active quenching circuit is connected to a second end of the coupling capacitor, is suitable for quenching the avalanche after receiving the pulse voltage signal output by the coupling capacitor, and is suitable for converting the pulse voltage signal into a digital voltage signal.

[0014] The controller has a first end connected to the active quenching circuit, and the digital trigger signal is suitable for controlling the quenching period of the active quenching circuit for quenching the avalanche current signal after receiving the pulse voltage signal of the quenching circuit.

[0015] According to an embodiment of the present application, the active quenching circuit comprises:

[0016] The discriminator is suitable for filtering the pulse voltage signal.

[0017] The D trigger is suitable for generating a digital trigger signal after receiving the filtered or pulsed voltage signal output by the discriminator.

[0018] The transistor is electrically connected to the D flip-flop at a first end, receives a quenching level at a second end, and is electrically connected to the cathode of the avalanche photodiode at a third end.

[0019] According to an embodiment of the present application, the active quenching circuit further comprises:

[0020] The shaping module is adapted to shape the digital trigger signal and transmit the shaped digital trigger signal to the transistor.

[0021] According to an embodiment of the present application, the controller is further adapted to provide a working voltage to the silicon carbide single-photon avalanche photodiode, the working voltage comprising a positive bias and a negative bias; the second end of the controller is connected to the second end of the extraction resistor to load the positive bias to the cathode of the silicon carbide single-photon avalanche photodiode; and the third end of the controller is connected to the anode of the silicon carbide single-photon avalanche photodiode to load the negative bias to the cathode of the silicon carbide single-photon avalanche photodiode.

[0022] According to an embodiment of the present application, the optical signal processing assembly comprises:

[0023] The fiber splitter is adapted to split the echo signal into n signals with the same light intensity.

[0024] The n processing units are adapted to process the n signals one by one, each processing unit comprising:

[0025] The fiber collimator is adapted to collimate the corresponding signal to obtain a collimated signal.

[0026] The adjustable optical attenuator is adapted to adjust the intensity of the collimated signal.

[0027] The filter is adapted to filter the collimated signal to obtain a sub-echo signal.

[0028] The filter of each processing unit has a different filtering wavelength, and the filtering wavelengths of the n filters correspond to the wavelengths of the n ultraviolet laser pulse signals one by one, so that the n sub-echo signals obtained after filtering correspond to the wavelengths of the n ultraviolet laser pulse signals one by one.

[0029] According to an embodiment of the present application, the processing unit further comprises:

[0030] The galvanometer is adapted to change the propagation direction of the sub-echo signal output by the filter.

[0031] The lens is suitable for focusing the sub-echo signals with changed propagation directions to corresponding single-photon detectors.

[0032] According to an embodiment of the present application, the data processing component comprises:

[0033] The time conversion unit is connected with the n detection units and is suitable for determining the difference between the time when each digital trigger signal is output by the detection unit and the emission time of the ultraviolet laser pulse signal, and accumulating all the differences obtained from the detection units into time distribution histogram data;

[0034] The correction unit is suitable for processing the time distribution histogram data obtained from each detection unit to reduce the influence of dark counts, after-pulses and dead time of the single-photon detector on the single-photon signal detection, and is suitable for performing smoothing processing on the processed time distribution histogram data to obtain corrected single-photon signal time distribution data;

[0035] The inversion unit is suitable for obtaining the spatial distribution data of the signal intensity of the n wavelength components with respect to the height according to the corrected single-photon signal time distribution data output by the n detection units.

[0036] According to an embodiment of the present application, in the single-photon detector, the avalanche generated by the silicon carbide single-photon avalanche photodiode is quenched by using the active quenching module, which can reduce the after-pulse probability of the avalanche photodiode, so that the semiconductor single-photon detector has a high saturation technical rate, and thus the inversion accuracy of the ozone concentration is high. At the same time, the semiconductor single-photon detector of the embodiment of the present application works in a free-running mode, and the echo signal has low distortion, which further improves the inversion accuracy of the ozone concentration. BRIEF DESCRIPTION OF DRAWINGS

[0037] The above and other objects, features and advantages of the present application will become more apparent from the following description of embodiments of the present application taken in conjunction with the accompanying drawings, in which:

[0038] Figure 1 A structural block diagram of a signal receiving device provided by an embodiment of the present application is shown;

[0039] Figure 2 A circuit diagram of a detection unit provided by an embodiment of the present application is shown;

[0040] Figure 3 A schematic diagram of a light signal processing component provided by an embodiment of the present application is shown;

[0041] Figure 4 A circuit diagram of an active quenching circuit provided by an embodiment of the present application is shown;

[0042] Figure 5A schematic diagram of a data processing assembly according to an embodiment of the application is shown.

[0043] Legend of reference signs

[0044] 1: emission assembly

[0045] 2: optical signal processing assembly

[0046] 21: fiber beam splitter

[0047] 22: processing unit

[0048] 221: fiber collimator

[0049] 222: adjustable optical attenuator

[0050] 223: optical filter

[0051] 224: galvanometer

[0052] 225: lens

[0053] 3: single photon detector

[0054] 31: silicon carbide single photon avalanche photodiode

[0055] 32: active quenching module

[0056] 321: extraction resistor

[0057] 322: coupling capacitor

[0058] 323: active quenching circuit

[0059] 323-1: discriminator

[0060] 323-2: D flip-flop

[0061] 323-3: transistor

[0062] 323-4: shaping module

[0063] 324: controller

[0064] 4: data processing assembly

[0065] 41: time conversion unit

[0066] 42: correction unit

[0067] 43: inversion unit

[0068] 5: reception assembly DETAILED DESCRIPTION

[0069] In the process of implementing the present application, it is found that the silicon carbide single photon detector has the characteristics of small size, low cost, stable performance, and insensitivity to visible light, and is suitable for application in ozone laser radar. However, the current silicon carbide single photon detector has a large afterpulse and a low saturated count rate, which causes serious distortion of the laser radar echo signal and cannot meet the application requirements of the ozone laser radar. Therefore, the silicon carbide single photon detector can be improved to reduce the afterpulse of the single photon detector and increase the saturated count rate of the single photon detector.

[0070] In order to make the objects, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to specific embodiments and drawings.

[0071] The terms used herein are only used to describe specific embodiments and are not intended to limit the present application. The terms "include", "contain" and the like used herein indicate the existence of the described features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0072] Figure 1 A structural block diagram of a signal receiving device provided by an embodiment of the present application is shown.

[0073] As shown in Figure 1 The signal receiving device comprises an optical signal processing assembly 2, a single photon detector 3 and a data processing assembly 4.

[0074] The optical signal processing assembly 2 is suitable for obtaining n sub-echo signals according to the received echo signal; each sub-echo signal comprises a plurality of single photon signals; the echo signal comprises n wavelength components, the n wavelength components are signals obtained after n ultraviolet laser pulse signals of different wavelengths respectively interact with ozone in the atmosphere, and the wavelengths of the n ultraviolet laser pulse signals are all located at the absorption peak of ozone. The n ultraviolet laser pulse signals of different wavelengths are emitted by the emission device 1 of the ozone laser radar, and the echo signal carries ozone information in the atmosphere. The wavelengths of the n sub-echo signals and the n ultraviolet laser pulse signals correspond one-to-one, and n≥2. The single photon detector 3 is coupled to the optical signal processing assembly 2, and the single photon detector 3 comprises n detection units, each detection unit is suitable for one-to-one single photon detection of a sub-echo signal of one wavelength. The data processing assembly 4 is suitable for obtaining spatial distribution data of signal intensity of n wavelength components with respect to height according to all single photon signals detected by the single photon detector 3, and the spatial distribution data of signal intensity of n wavelength components with respect to height is used to obtain ozone concentration information in the atmosphere. As shown in Figure 1 The signal receiving device further comprises a receiving assembly 5, which is used to receive the echo signal and transmit the echo signal to the optical signal processing assembly 2 through an ultraviolet optical fiber.

[0075] Figure 2 A circuit diagram of the detection unit according to an embodiment of the present application is shown.

[0076] As shown in Figure 2 the detection unit comprises a silicon carbide single photon avalanche photodiode 31 and an active quenching module 32. When the silicon carbide single photon avalanche photodiode 31 in a standby state receives a single photon signal, the silicon carbide single photon avalanche photodiode 31 generates an avalanche, and an avalanche current signal is generated. The active quenching module 32 is adapted to quench the avalanche to restore the silicon carbide single photon avalanche photodiode to the standby state, and is adapted to convert the received avalanche current signal into a digital trigger signal output to complete the detection of the single photon signal.

[0077] According to an embodiment of the present application, in the semiconductor single photon detector 3, the active quenching module 32 is used to quench the avalanche generated by the silicon carbide single photon avalanche photodiode 31, which can reduce the post-pulse probability of the silicon carbide single photon avalanche photodiode 31, so that the single photon detector has a high saturation count rate, and thus the inversion accuracy of the ozone concentration is high. At the same time, the semiconductor single photon detector of the embodiment of the present application works in a free-running mode, and the echo signal has low distortion, further improving the inversion accuracy of the ozone concentration.

[0078] According to an embodiment of the present application, the peak response of the silicon carbide single photon avalanche photodiode is located in the solar blind band, and the solar background noise is extremely low, so that the ozone lidar has a high signal-to-noise ratio. According to an embodiment of the present application, the single photon detector 3 based on the silicon carbide single photon avalanche photodiode 31 has the advantages of small size, easy integration, stable performance, mild working conditions, and easy array expansion.

[0079] According to an embodiment of the present application, the optical signal processing assembly 2 comprises an optical fiber beam splitter 21 and n processing units 22.

[0080] Figure 3 A schematic diagram of the optical signal processing assembly according to an embodiment of the present application is shown.

[0081] As shown in Figure 3 the optical fiber beam splitter 22 is adapted to divide the echo signal into n signals with the same light intensity. Figure 3For example, n=2 is taken as an example for illustration. Each processing unit 22 is adapted to process one-to-one corresponding one-way signal, each processing unit 22 comprises: a fiber collimator 221, an adjustable optical attenuator 222, and a filter 223. The fiber collimator 221 is adapted to collimate the corresponding one-way signal to obtain a collimated signal. The adjustable optical attenuator 222 is adapted to adjust the intensity of the collimated signal. The filter 223 is used to filter the collimated signal to obtain a sub-echo signal. The filter wavelengths of the filters of different processing units are different, and the filter wavelengths of the n filters correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals, so that the wavelengths of the n sub-echo signals obtained after filtering correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals. The processing unit 22 according to the embodiment of the present application further comprises: a galvanometer 224 and a lens 225. The galvanometer 224 is adapted to change the propagation direction of the sub-echo signal output by the filter 223. The lens 225 is adapted to focus the sub-echo signal with the changed propagation direction to the single-photon detector 3 of the corresponding detection unit.

[0082] According to the embodiment of the present application, with continued reference to Figure 2 , the active quenching module 32 comprises: an extraction resistor 321, i.e. R1, a coupling capacitor 322, i.e. C1, an active quenching circuit 323, and a controller 324.

[0083] The first end of the extraction resistor 321 is connected to the cathode of the avalanche photodiode 31, and the extraction resistor 321 is used to convert the avalanche current signal into a pulse voltage signal (i.e. a negative pulse avalanche signal). The first end of the coupling capacitor 322 is connected to the silicon carbide single-photon avalanche photodiode 31, and the coupling capacitor 322 is adapted to couple the pulse voltage signal. The active quenching circuit 323 is connected to the second end of the coupling capacitor 322, and is adapted to quench the avalanche after receiving the pulse voltage signal output by the coupling capacitor 322, and is adapted to convert the pulse voltage signal into a digital trigger signal. The first end of the controller 324 is connected to the active quenching circuit 323, and is adapted to convert the pulse voltage signal from the active quenching circuit 323 into a digital trigger signal for output, and is adapted to control the quenching period (i.e. quenching duration) of the active quenching circuit 323 to quench the avalanche pulse signal after receiving the digital trigger signal from the quenching circuit 323.

[0084] According to an embodiment of the present application, the controller 324 is further adapted to provide a working voltage to the silicon carbide single photon avalanche photodiode 31, the working voltage comprising a positive bias and a negative bias; a second end of the controller 23 is connected to a second end of the extraction resistor 321 to load the positive bias (+Bias) to the cathode of the avalanche photodiode 31. When no avalanche occurs, the silicon carbide single photon avalanche photodiode 31 is in an off state, thus the positive bias (+Bias) has no voltage drop on the extraction resistor 321, and the voltage of the cathode of the silicon carbide single photon avalanche photodiode 31 is the positive bias; a third end of the controller 23 is connected to the anode of the silicon carbide single photon avalanche photodiode 31 to load the negative bias (-Bias) to the cathode of the silicon carbide single photon avalanche photodiode 31. Under the action of the positive bias and the negative bias, the silicon carbide single photon avalanche photodiode 31 is in a Geiger mode, also known as a single photon detection mode.

[0085] Figure 4 A circuit diagram of the active quenching circuit provided according to an embodiment of the present application is shown.

[0086] According to an embodiment of the present application, the active quenching circuit 323 comprises a discriminator 323-1, a D flip-flop 323-2, and a transistor 323-3.

[0087] The discriminator 323-1 is connected to the second end of the coupling capacitor and is adapted to filter the pulse voltage signal, i.e. to extract the signal with an amplitude greater than the discrimination threshold from the AC coupling output signal of the coupling capacitor. The D flip-flop 323-2 is electrically connected to the discriminator 323-1 and is adapted to generate a digital trigger signal after receiving the filtered or pulse voltage signal output by the discriminator 323-1, and the digital trigger signal is a positive signal. The transistor can be a bipolar junction transistor. The first end (base level, i.e. B level) of the transistor 323-3 is electrically connected to the D flip-flop 323-2, and the second end (emitter level, i.e. E level) of the transistor 323-3 is used to receive a quenching level (fixed positive voltage V1), and the quenching level is less than the positive bias voltage and the negative bias voltage. The third end (collector level, i.e. C level) of the transistor 323-3 is electrically connected to the cathode of the avalanche photodiode 31. When no avalanche signal is detected, the D flip-flop 323-2 outputs a low voltage V2 to the base of the transistor 323-3, and the transistor 323-3 is in an off state, at this time, the active quenching does not work and does not affect the working state of the silicon carbide single-photon avalanche photodiode 31; when the avalanche signal is generated and received by the discriminator 323-1 and the D flip-flop 323-3, during the output of the high voltage (digital trigger signal) by the D flip-flop 323-3, the transistor 323-3 is turned on when the first end of the transistor 323-3 receives the digital trigger signal, and when the transistor 323-3 is turned on, the quenching level is loaded to the cathode of the avalanche photodiode 31 through the transistor 323-3, so as to lower the cathode voltage of the silicon carbide single-photon avalanche photodiode 31 and realize the quenching of the avalanche current signal. The controller 324 is used to control the conduction time of the transistor 323-3, i.e. to control the time length of the quenching level loaded to the cathode of the silicon carbide single-photon avalanche photodiode 31, and to control the quenching period. After a short delay (quenching period), the transistor 323-3 is turned off, the cathode voltage of the silicon carbide single-photon avalanche photodiode 31 returns to +Bias, and the next photon detection is prepared.

[0088] According to an embodiment of the present application, the active quenching circuit 323 further comprises a shaping module 323-4 adapted to shape the digital trigger signal and transmit the shaped digital trigger signal to the transistor 323-3. The shaping module 323-4 comprises an RC circuit composed of a resistor R2 and a capacitor C2. When the D flip-flop 323-2 receives the avalanche signal output by the discriminator 221, the D flip-flop 323-2 outputs a digital trigger signal (positive signal) and charges the D flip-flop through the RC circuit composed of the resistor R2 and the capacitor C2, and after the voltage at the Reset end reaches the threshold value, the output end of the D flip-flop is pulled low to control the pulse width of the positive signal, i.e. the digital trigger signal. The D flip-flop is connected to the controller, and the digital trigger signal of the D flip-flop is also transmitted to the controller, and the digital trigger signal transmitted to the controller is converted into a digital trigger signal.

[0089] Figure 5 A schematic diagram of a data processing assembly according to an embodiment of the present application is shown.

[0090] According to an embodiment of the present application, as shown in Figure 5 , the data processing assembly 4 comprises a time conversion unit 41, a correction unit 42, and an inversion unit 43.

[0091] The time conversion unit 41 is connected to n detection units, and is adapted to determine the difference between the time when each digital trigger signal is output by the detection unit and the emission time of the ultraviolet laser pulse signal, and to accumulate all the differences obtained from the detection units into time distribution histogram data.

[0092] The correction unit 42 is adapted to process the time distribution histogram data obtained from each detection unit to reduce the influence of dark counts, after-pulses and dead time of the single photon detector on the detection of single photon signals, and to perform smoothing processing on the processed time distribution histogram data to remove noise signals, to obtain corrected single photon signal time distribution data.

[0093] The inversion unit 43 is adapted to obtain spatial distribution data of signal intensity of n wavelength components with respect to height based on the corrected single photon signal time distribution data output by the n detection units.

[0094] According to an embodiment of the present application, when n = 2, the ozone concentration distribution at different heights in the atmosphere is as follows.

[0095] When n = 2, the wavelengths of the ultraviolet laser pulse signal are a first wavelength (wavelength 1) and a second wavelength (wavelength 2). The ozone concentration inversion can be performed according to the distribution of signal intensity of the first wavelength and the second wavelength at different distances to obtain ozone concentration information at different distances. Specifically, the signal intensity received by the two wavelengths satisfies the following laser radar equations, respectively:

[0096] (1)

[0097] (2)

[0098] wherein represents the output optical power of the ultraviolet laser pulse signal with wavelength , i = 1 or 2. represents the height, represents the light field overlap factor between the emission assembly 1 and the receiving assembly 5, represents the effective receiving area of the signal receiving assembly, represents the resolution of the ozone laser radar, represents the backscattering factor of the atmosphere, and an attenuation factor representing the atmosphere, an absorption cross section of the ozone for ultraviolet laser pulse signals, , an ozone concentration at a height of R.

[0099] It should be noted that if the first wavelength and the second wavelength used are relatively close, the difference between the two at the same position can be ignored, and the ozone concentration distribution satisfies the following equation by dividing the two equations: and

[0100] (3)

[0101] wherein represents the differential absorption cross section of the ozone at and two wavelengths. The ozone concentration is expressed as follows:

[0102] (4)

[0103] According to the embodiment of the present application, the avalanche generated by the silicon carbide single photon avalanche photodiode 311 is quenched by the active quenching module, which can reduce the post-pulse probability of the silicon carbide single photon avalanche photodiode 311, so that the single photon detector has a high saturation rate, and the inversion accuracy of the ozone concentration is high.

[0104] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are only examples of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.​

Claims

1. A signal receiving device for ozone lidar, characterized in that, include: An optical signal processing component is suitable for obtaining n sub-echo signals based on a received echo signal; wherein each sub-echo signal includes multiple single-photon signals; the echo signal includes n wavelength components, which are obtained by interacting with ozone in the atmosphere by n ultraviolet laser pulse signals of different wavelengths respectively, the n ultraviolet laser pulse signals of different wavelengths are emitted by the transmitting device of the ozone lidar, the echo signal carries ozone information in the atmosphere, and the wavelengths of the n sub-echo signals and the n ultraviolet laser pulse signals correspond one-to-one, n≥2; A single-photon detector, coupled to the optical signal processing component, comprises n detection units, each detection unit being adapted to perform single-photon detection on a sub-echo signal of one wavelength in a one-to-one correspondence. The detection unit includes: A silicon carbide single-photon avalanche photodiode, when in a probe-ready state and receiving a single-photon signal, undergoes an avalanche and generates an avalanche current signal; and An active quenching module is suitable for quenching the avalanche to restore the silicon carbide single-photon avalanche photodiode to the state to be detected, thereby continuing to detect other single-photon signals; and is also suitable for converting the avalanche current signal into a digital trigger signal output to complete the detection of the single-photon signal; and The data processing component is suitable for obtaining spatial distribution data of the signal intensity of n wavelength components with altitude based on all single-photon signals detected by the single-photon detector. The spatial distribution data of the signal intensity of n wavelength components with altitude is used to obtain information on ozone concentration in the atmosphere. The active quenching module includes: An extraction resistor is provided, the first end of which is connected to the cathode of the silicon carbide single-photon avalanche photodiode. The extraction resistor is used to convert the avalanche current signal into a pulse voltage signal. A coupling capacitor, the first end of which is connected to the cathode of the silicon carbide single-photon avalanche photodiode, is used to couple the pulse voltage signal. An active quenching circuit, connected to the second terminal of the coupling capacitor, is suitable for quenching the avalanche after receiving a pulse voltage signal output by the coupling capacitor, and for converting the pulse voltage signal into a digital trigger signal. A controller, the first end of which is connected to the active quenching circuit, is adapted to control the active quenching circuit to quench the avalanche current signal during a quenching period after receiving a digital trigger signal from the quenching circuit. The active quenching circuit includes: A discriminator suitable for filtering the pulse voltage signal; A D flip-flop is used to generate the digital trigger signal after receiving a filtered or pulse voltage signal output by the discriminator. A transistor, wherein the first terminal of the transistor is electrically connected to the D flip-flop, the second terminal of the transistor is used to receive a quenching level, and the third terminal of the transistor is electrically connected to the cathode of the avalanche photodiode; wherein the transistor is turned on when the first terminal of the transistor receives the digital trigger signal, and when the transistor is turned on, the quenching level is transmitted via the transistor to the cathode of the silicon carbide single-photon avalanche photodiode to quench the avalanche current signal.

2. The signal receiving device according to claim 1, characterized in that, The active quenching circuit also includes: The shaping module is suitable for shaping the digital trigger signal and transmitting the shaped digital trigger signal to the transistor.

3. The signal receiving device according to claim 1, characterized in that, The controller is also adapted to provide an operating voltage to the silicon carbide single-photon avalanche photodiode, the operating voltage including a positive bias and a negative bias; a second terminal of the controller is connected to a second terminal of the extraction resistor to apply a positive bias to the cathode of the silicon carbide single-photon avalanche photodiode; a third terminal of the controller is connected to the anode of the silicon carbide single-photon avalanche photodiode to apply a negative bias to the anode of the silicon carbide single-photon avalanche photodiode.

4. The signal receiving device according to claim 1, characterized in that, The optical signal processing component includes: An optical fiber beam splitter is suitable for splitting the echo signal into n signals with the same optical intensity. There are n processing units, each of which is suitable for processing one corresponding signal. Each processing unit includes: Fiber optic collimators are used to collimate a single signal to obtain a collimated signal. An adjustable optical attenuator is used to adjust the intensity of the collimated signal; A filter is used to filter the collimated signal to obtain the sub-echo signal; In this process, the filters of different processing units have different filtering wavelengths, and the filtering wavelengths of the n filters correspond one-to-one with the wavelengths of the n ultraviolet laser pulse signals, so that the n sub-echo signals obtained after filtering correspond one-to-one with the wavelengths of the n ultraviolet laser pulse signals.

5. The signal receiving device according to claim 4, characterized in that, The processing unit further includes: A galvanometer is used to change the propagation direction of the sub-echo signal output by the filter. Lenses are used in single-photon detectors to focus sub-echo signals with altered propagation directions onto the corresponding detection units.

6. The signal receiving device according to claim 1, characterized in that, The data processing component includes: A time conversion unit, connected to n detection units, is used to determine the difference between the time when each digital trigger signal is output by the detection unit and the emission time of the ultraviolet laser pulse signal, and accumulates all the differences obtained from the detection units into time distribution histogram data; The correction unit is suitable for processing the time distribution histogram data obtained from each detection unit to reduce the influence of the dark count, afterpulse, and dead time of the single-photon detector on the detection of single-photon signals, and is also suitable for smoothing the processed time distribution histogram data to obtain corrected single-photon signal time distribution data. The inversion unit is suitable for obtaining the spatial distribution data of the signal intensity of n wavelength components with height based on the corrected single-photon signal time distribution data output by n detection units.

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