Signal receiving device for ozone laser radar

Abstract

A signal receiving device for an ozone laser radar comprises an optical signal processing assembly which is suitable for obtaining n sub-echo signals according to a received echo signal; the single-photon detector comprises n detection units, each detection unit is suitable for carrying out single-photon detection on sub-echo signals of one wavelength in a one-to-one correspondence mode, each detection unit comprises a silicon carbide single-photon avalanche photodiode, and when the silicon carbide single-photon avalanche photodiode in a to-be-detected state receives a single-photon signal, the silicon carbide single-photon avalanche photodiode in a to-be-detected state receives the single-photon signal; the silicon carbide single-photon avalanche photodiode generates avalanche and generates an avalanche current signal; the active quenching module is suitable for quenching avalanche, so that the silicon carbide single-photon avalanche photodiode is recovered to the to-be-detected state; and the data processing assembly is suitable for obtaining spatial distribution data of the signal intensity of the n wavelength components along with the height according to all the single-photon signals detected by the single-photon detector.

Description

Technical Field

[0001] The invention relates to the field of ozone detection, and in particular to a signal receiving device for an ozone laser radar. Background Art

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

[0003] Most ozone lidars work in the ultraviolet band. Due to the scattering and absorption of the atmosphere, the ultraviolet light signals they emit will decay exponentially as the propagation distance increases. Therefore, this type of radar has extremely high requirements for the detection sensitivity of ultraviolet weak light. Single-photon detectors can detect weak light at the level of a single photon and have quantum-limited sensitivity, which is conducive to improving the detection distance and accuracy of ozone lidars. At present, the main method for realizing single-photon detection in the ultraviolet band is to use photomultiplier tubes, which have inherent disadvantages such as short life, magnetic field sensitivity, and the need for vacuum working conditions. Summary of the invention

[0004] In view of this, the present invention provides a signal receiving device for ozone laser radar, comprising:

[0005] An optical signal processing component is used to obtain n sub-echo signals according to the received echo signal; wherein each sub-echo signal includes multiple single photon signals; the echo signal includes n wavelength components, the n wavelength components are obtained after n ultraviolet laser pulse signals of different wavelengths interact with ozone in the atmosphere respectively, the n ultraviolet laser pulse signals of different wavelengths are emitted by the transmitting device of the ozone laser radar, 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;

[0006] A single photon detector is coupled to the optical signal processing component. The single photon detector includes n detection units. Each detection unit is suitable for performing single photon detection on a sub-echo signal of a wavelength in a one-to-one correspondence. The detection unit includes:

[0007] A silicon carbide single-photon avalanche photodiode, when the avalanche photodiode in a detection state receives a single-photon signal, the silicon carbide single-photon avalanche photodiode avalanches and generates an avalanche current signal; and

[0008] An active quenching module, which is suitable for quenching the avalanche to restore the silicon carbide single-photon avalanche photodiode to a detection state, thereby continuing to detect other single-photon signals and for converting the avalanche current signal into a digital trigger signal output to complete the detection of single photons; and

[0009] The data processing component is suitable for obtaining spatial distribution data of signal intensity of n wavelength components with height according to all single photon signals detected by the single photon detector. The spatial distribution data of signal intensity of n wavelength components with height is used to obtain ozone concentration information in the atmosphere.

[0010] According to an embodiment of the present invention, the active quenching module includes:

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

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

[0013] An active quenching circuit, connected to the second end of the coupling capacitor, adapted to quench the avalanche after receiving the pulse voltage signal output by the coupling capacitor, and adapted to convert the pulse voltage signal into a digital voltage signal;

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

[0015] According to an embodiment of the present invention, the active quenching circuit includes:

[0016] Discriminator, suitable for filtering pulse voltage signals;

[0017] A D flip-flop, adapted to generate a digital trigger signal after receiving a filtered or pulsed voltage signal output by the discriminator;

[0018] A transistor, wherein the first end of the transistor is electrically connected to a D trigger, the second end of the transistor is used to receive a quenching level, and the third end of the transistor is electrically connected to a cathode of an avalanche photodiode; wherein the transistor is turned on when the first end of the transistor receives a digital trigger signal, and when the transistor is turned on, the quenching level is transmitted to the cathode of the silicon carbide single-photon avalanche photodiode via the transistor, thereby quenching the avalanche current signal.

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

[0020] The shaping module is suitable for shaping the digital trigger signal and transmitting the shaped digital trigger signal to the transistor.

[0021] According to an embodiment of the present invention, the controller is also suitable for providing an operating voltage to a silicon carbide single-photon avalanche photodiode, the operating voltage including a positive bias voltage and a negative bias voltage; the second end of the controller is connected to the second end of the extraction resistor to load the positive bias voltage to the cathode of the silicon carbide single-photon avalanche photodiode; the third end of the controller is connected to the anode of the silicon carbide single-photon avalanche photodiode to load the negative bias voltage to the cathode of the silicon carbide single-photon avalanche photodiode.

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

[0023] Fiber optic beam splitter, suitable for dividing the echo signal into n signals with the same light intensity;

[0024] n processing units, each processing unit is suitable for processing one signal on a one-to-one basis, and each processing unit includes:

[0025] The optical fiber collimator is suitable for collimating a corresponding signal to obtain a collimated signal;

[0026] An adjustable optical attenuator, suitable for adjusting the intensity of the collimated signal;

[0027] A filter, used for filtering the collimation signal to obtain a sub-echo signal;

[0028] The filters of different processing units have different filtering wavelengths, and the filtering wavelengths of the n filters correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals, so that the n sub-echo signals obtained after filtering correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals.

[0029] According to an embodiment of the present invention, the processing unit further includes:

[0030] A galvanometer, which is used to change the propagation direction of the sub-echo signal output by the filter;

[0031] The lens is suitable for focusing the sub-echo signal after the propagation direction is changed to the single-photon detector of the corresponding detection unit.

[0032] According to an embodiment of the present invention, the data processing component includes:

[0033] A time conversion unit, connected to the n detection units, 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 accumulate all the differences obtained according to the detection unit into time distribution histogram data;

[0034] A correction unit, adapted to process the time distribution histogram data obtained from each detection unit to reduce the influence of dark counts, afterpulses and dead time of the single-photon detector on the single-photon signal detection, and adapted to smooth 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 n wavelength components with height according to the time distribution data of the corrected single photon signal output by the n detection units.

[0036] According to an embodiment of the present invention, in a single-photon detector, an active quenching module is used to quench the avalanche generated by a silicon carbide single-photon avalanche photodiode, which can reduce the probability of post-pulse of the avalanche photodiode, so that the semiconductor single-photon detector has a higher saturation technology rate, thereby making the inversion accuracy of the ozone concentration higher. At the same time, the semiconductor single-photon detector of the embodiment of the present invention works in a free-running mode, and the echo signal has a lower distortion, which further improves the inversion accuracy of the ozone concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

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

[0039] Figure 2 shows a circuit diagram of a detection unit provided according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of an optical signal processing component provided according to an embodiment of the present invention is shown;

[0041] Figure 4 A circuit diagram of an active quenching circuit provided according to an embodiment of the present invention is shown;

[0042] Figure 5A schematic diagram of a data processing component provided according to an embodiment of the present invention is shown.

[0043] Description of Reference Numerals

[0044] 1: Transmitter

[0045] 2: Optical signal processing components

[0046] 21: Fiber Optic Splitter

[0047] 22: Processing Unit

[0048] 221: Fiber Collimator

[0049] 222: Variable Optical Attenuator

[0050] 223: 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 resistance

[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 components

[0065] 41: Time conversion unit

[0066] 42: Correction Unit

[0067] 43: Inversion unit

[0068] 5: Receiving component DETAILED DESCRIPTION

[0069] In the process of realizing the present invention, it is found that the silicon carbide single-photon detector has the characteristics of small size, low cost, stable performance, insensitivity to visible light, etc., and is suitable for application in ozone laser radar. However, the current silicon carbide single-photon detector has a large after-pulse and a low saturation count rate, which leads to 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 after-pulse of the single-photon detector and increase the saturation count rate of the single-photon detector.

[0070] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0071] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the 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 according to an embodiment of the present invention is shown.

[0073] like Figure 1 As shown, the signal receiving device includes: an optical signal processing component 2, a single photon detector 3 and a data processing component 4.

[0074] The optical signal processing component 2 is suitable for obtaining n sub-echo signals according to the received echo signal; wherein each sub-echo signal includes multiple single photon signals; the echo signal includes n wavelength components, and the n wavelength components are signals obtained after n ultraviolet laser pulse signals of different wavelengths 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 transmitting device 1 of the ozone laser radar, and the echo signal carries the 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 component 2, and the single photon detector 3 includes n detection units, and each detection unit is suitable for performing single photon detection on a sub-echo signal of a wavelength in a one-to-one correspondence. The data processing component 4 is suitable for obtaining the spatial distribution data of the signal intensity of the n wavelength components with the height according to all the single photon signals detected by the single photon detector 3, and the spatial distribution data of the signal intensity of the n wavelength components with the height is used to obtain the ozone concentration information in the atmosphere. like Figure 1 As shown, the signal receiving device further includes: a receiving component 5, which is used to receive the echo signal and transmit the echo signal to the optical signal processing component 2 through the ultraviolet optical fiber.

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

[0076] like Figure 2 As shown, the detection unit includes: a silicon carbide single-photon avalanche photodiode 31 and an active quenching module 32. When the silicon carbide single-photon avalanche photodiode 31 in the state to be detected receives a single-photon signal, the silicon carbide single-photon avalanche photodiode 31 avalanches and generates an avalanche current signal. The active quenching module 32 is suitable for quenching the avalanche to restore the silicon carbide single-photon avalanche photodiode to the state to be detected, and is suitable for converting 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 invention, in the semiconductor single-photon detector 3, the avalanche generated by the silicon carbide single-photon avalanche photodiode 31 is quenched by using an active quenching module 32, which can reduce the probability of post-pulses of the silicon carbide single-photon avalanche photodiode 31, so that the single-photon detector has a higher saturation count rate, thereby making the inversion accuracy of the ozone concentration higher. At the same time, the semiconductor single-photon detector of the embodiment of the present invention works in a free-running mode, and the echo signal has a lower distortion, which further improves the inversion accuracy of the ozone concentration.

[0078] According to an embodiment of the present invention, the peak response of the silicon carbide single-photon avalanche photodiode is located in the solar-blind band, and the sunlight background noise is extremely low, so that the ozone lidar has a higher signal-to-noise ratio. According to an embodiment of the present invention, 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 invention, the optical signal processing component 2 includes: an optical fiber splitter 21 and n processing units 22 .

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

[0081] like Figure 3 As shown, the optical fiber beam splitter 22 is suitable for dividing the echo signal into n signals with the same light intensity. Figure 3In the example, n=2 is used for explanation. Each processing unit 22 is suitable for processing one signal in a one-to-one correspondence, and each processing unit 22 includes: a fiber collimator 221, an adjustable optical attenuator 222, and a filter 223. The fiber collimator 222 is suitable for collimating the corresponding one signal to obtain a collimated signal. The adjustable optical attenuator 222 is suitable for adjusting the intensity of the collimated signal. The filter 223 is used to filter the collimated signal to obtain a sub-echo signal. Among them, the filtering wavelengths of the filters of different processing units are different, and the filtering wavelengths of the n filters correspond to the wavelengths of the n ultraviolet laser pulse signals one-to-one, so that the n sub-echo signals obtained after filtering correspond to the wavelengths of the n ultraviolet laser pulse signals one-to-one. According to an embodiment of the present invention, the processing unit 22 also includes: a galvanometer 224 and a lens 225. The galvanometer 224 is suitable for changing the propagation direction of the sub-echo signal output by the filter 223. The lens 225 is suitable for focusing the sub-echo signal after the propagation direction is changed to the single-photon detector 3 of the corresponding detection unit.

[0082] According to an embodiment of the present invention, continue to refer to Figure 2 The active quenching module 32 includes: an extraction resistor 321 ie R1 , a coupling capacitor 322 ie 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 suitable for coupling the pulse voltage signal. The active quenching circuit 323 is connected to the second end of the coupling capacitor 3, and is suitable for quenching the avalanche after receiving the pulse voltage signal output by the coupling capacitor 322, and is suitable for converting 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 suitable for converting the pulse voltage signal from the active quenching circuit 323 into a digital trigger signal for output, and is suitable for controlling 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 of the quenching circuit 323.

[0084] According to an embodiment of the present invention, the controller 324 is also suitable for providing an operating voltage to the silicon carbide single-photon avalanche photodiode 31, and the operating voltage includes a positive bias voltage and a negative bias voltage; the second end of the controller 23 is connected to the second end of the extraction resistor 321 to load the positive bias voltage (+Bias) to the cathode of the avalanche photodiode 31. When no avalanche occurs, the silicon carbide single-photon avalanche photodiode 31 is in a non-conducting state, so the positive bias voltage (+Bias) does not have a voltage drop in the extraction resistor 321, and the voltage of the cathode of the silicon carbide single-photon avalanche photodiode 31 is the positive bias voltage; the 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 voltage (-Bias) to the cathode of the silicon carbide single-photon avalanche photodiode 31. Under the action of the positive bias voltage and the negative bias voltage, the silicon carbide single-photon avalanche photodiode 31 is in the Geiger mode, also known as the single-photon detection mode.

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

[0086] According to the embodiment of the present invention, the active quenching circuit 323 includes: 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 suitable for filtering the pulse voltage signal, that is, extracting the signal whose amplitude is greater than the discrimination threshold in the signal output by the coupling capacitor AC coupling. The D trigger 323-2 is electrically connected to the discriminator 323-1, and is suitable for generating 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, for example, a bipolar junction transistor. The first end (base, i.e., B level) of the transistor 323-3 is electrically connected to the D trigger 323-2, and the second end (emitter, i.e., E level) of the transistor 323-3 is used to receive the quenching level (fixed positive level V1), and the quenching level is less than the positive bias voltage and the negative bias voltage. The third end (collector, 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 trigger 323-2 outputs a low level V2 to the base of the transistor 323-3, and the transistor 323-3 is in the off state. At this time, the active quenching does not work and will 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 trigger 323-3, the D trigger 323-3 outputs a high level (digital trigger signal), and the first end of the transistor 323-3 is turned on when receiving the digital trigger signal. 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, and the cathode voltage of the silicon carbide single-photon avalanche photodiode 31 is pulled down to achieve quenching of the avalanche current signal. The controller 324 is used to control the on-time of the transistor 323-3, that is, to control the time length of the quenching level loaded to the cathode of the silicon carbide single-photon avalanche photodiode 31, thereby controlling the quenching period. After a short delay (quenching period), the transistor 323 - 3 is turned off, and the cathode voltage of the silicon carbide single-photon avalanche photodiode 31 is restored to +Bias, ready for the next photon detection.

[0088] According to an embodiment of the present invention, the active quenching circuit 323 also includes: a shaping module 323-4, which is suitable for shaping the digital trigger signal and transmitting the shaped digital trigger signal to the transistor 323-3. The shaping module 323-4 includes an RC circuit composed of a resistor R2 and a capacitor C2. When the D trigger 323-2 of the embodiment of the present invention receives the avalanche signal output by the discriminator 221, the D trigger 323-2 will output a digital trigger signal (positive signal) and charge the D trigger through the RC circuit composed of the resistor R2 and the capacitor C2, and pull down the output end of the D trigger after the voltage at the Reset end reaches the threshold to control the pulse width of the positive signal, i.e., the digital trigger signal. The D trigger is connected to the controller, and the digital trigger signal of the D trigger is also transmitted to the controller at the same time. After the digital trigger signal is transmitted to the controller, it is converted into a digital trigger signal.

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

[0090] According to an embodiment of the present invention, Figure 5 As shown, the data processing component 4 includes: 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 suitable for determining the difference between the time when the detection unit outputs each digital trigger signal and the emission time of the ultraviolet laser pulse signal, and accumulating all the differences obtained according to the detection unit into time distribution histogram data.

[0092] The correction unit 42 is suitable for processing the time distribution histogram data obtained according to each detection unit to reduce the influence of the dark count, after-pulse and dead time of the single-photon detector on the single-photon signal detection, and is suitable for smoothing 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 intensities of n wavelength components with respect to heights according to the modified time distribution data of single photon signals output by the n detection units.

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

[0095] When n=2, the wavelengths of the ultraviolet laser pulse signal are the first wavelength (wavelength 1) and the second wavelength (wavelength 2). Ozone concentration inversion can invert the ozone concentration information at different distances based on the distribution of the first wavelength and the second wavelength signal intensity at different distances. Specifically, the signal intensity received at the two wavelengths satisfies the following lidar equations:

[0096] (1)

[0097] (2)

[0098] in The representative wavelength is The output optical power of the ultraviolet laser pulse signal, i=1 or 2. Represents height, represents the light field overlap factor between the transmitting component 1 and the receiving component 5, Represents the effective receiving area of ​​the signal receiving component, represents the resolution of the ozone lidar, represents the atmospheric backscattering factor, and represents the atmospheric attenuation factor, Represents ozone for The absorption cross section of the ultraviolet laser pulse signal, , Represents the ozone concentration at an altitude of R.

[0099] It should be noted that if the first wavelength and the second wavelength used are close, the and The difference between these two terms at two wavelengths, then dividing the two equations can give the ozone concentration distribution that satisfies the following equation:

[0100] (3)

[0101] in Represents ozone in and The differential absorption cross section at two wavelengths. The ozone concentration is expressed as follows:

[0102] (4)

[0103] According to an embodiment of the present invention, an active quenching module is used to quench the avalanche generated by the silicon carbide single-photon avalanche photodiode 311, which can reduce the after-pulse probability of the silicon carbide single-photon avalanche photodiode 311, so that the single-photon detector has a higher saturation technology rate and the inversion accuracy of the ozone concentration is higher.

[0104] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A signal receiving device for ozone laser radar, characterized in that: include: An optical signal processing component, adapted to obtain n sub-echo signals according to a received echo signal; wherein each of the sub-echo signals includes a plurality of single-photon signals; the echo signal includes n wavelength components, the n wavelength components are obtained after n ultraviolet laser pulse signals of different wavelengths interact with ozone in the atmosphere respectively, the n ultraviolet laser pulse signals of different wavelengths are emitted by a transmitting device of the ozone laser radar, the echo signal carries ozone information in the atmosphere, the n sub-echo signals correspond to the wavelengths of the n ultraviolet laser pulse signals one by one, and n≥2; A single photon detector is coupled to the optical signal processing component, wherein the single photon detector includes n detection units, each detection unit is suitable for performing single photon detection on a sub-echo signal of a wavelength in a one-to-one correspondence, and the detection unit includes: A silicon carbide single-photon avalanche photodiode, when the silicon carbide single-photon avalanche photodiode in a state to be detected receives a single-photon signal, the silicon carbide single-photon avalanche photodiode avalanches and generates an avalanche current signal; and An active quenching module, adapted to quench the avalanche so as to restore the silicon carbide single-photon avalanche photodiode to the state to be detected, thereby continuing to detect other single-photon signals, and adapted to convert 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 the spatial distribution data of the signal intensity of n wavelength components with height according to all single photon signals detected by the single photon detector. The spatial distribution data of the signal intensity of n wavelength components with height is used to obtain the ozone concentration information in the atmosphere.

2. The signal receiving device according to claim 1, characterized in that: The active quenching module comprises: An extraction resistor, a first end of which is connected to the cathode of the silicon carbide single-photon avalanche photodiode, and the extraction resistor is used to convert the avalanche current signal into a pulse voltage signal; A coupling capacitor, wherein a first end of the coupling capacitor is connected to a cathode of the silicon carbide single-photon avalanche photodiode, and the coupling capacitor is suitable for coupling the pulse voltage signal; an active quenching circuit, connected to the second end of the coupling capacitor, adapted to quench the avalanche after receiving a pulse voltage signal output by the coupling capacitor, and convert the pulse voltage signal into a digital trigger signal; A controller, wherein a first end of the controller is connected to the active quenching circuit, and is adapted to control a quenching period during which the active quenching circuit quenches the avalanche current signal after receiving a digital trigger signal of the quenching circuit.

3. The signal receiving device according to claim 2, characterized in that: The active quenching circuit comprises: a discriminator adapted to filter the pulse voltage signal; A D flip-flop, adapted to generate the digital trigger signal after receiving the filtered or pulse voltage signal output by the discriminator; A transistor, wherein the first end of the transistor is electrically connected to the D trigger, the second end of the transistor is used to receive the quenching level, and the third end of the transistor is electrically connected to the cathode of the avalanche photodiode; wherein the transistor is turned on when the first end of the transistor receives the digital trigger signal, and when the transistor is turned on, the quenching level is transmitted to the cathode of the silicon carbide single-photon avalanche photodiode via the transistor, thereby quenching the avalanche current signal.

4. The signal receiving device according to claim 3, characterized in that: The active quenching circuit further includes: The shaping module is adapted to shape the digital trigger signal and transmit the shaped digital trigger signal to the transistor.

5. The signal receiving device according to claim 2, characterized in that: The controller is also suitable for providing an operating voltage to the silicon carbide single-photon avalanche photodiode, and the operating voltage includes a positive bias voltage and a negative bias voltage; the second end of the controller is connected to the second end of the extraction resistor to load the positive bias voltage to the cathode of the silicon carbide single-photon avalanche photodiode; the third end of the controller is connected to the anode of the silicon carbide single-photon avalanche photodiode to load the negative bias voltage to the cathode of the silicon carbide single-photon avalanche photodiode.

6. The signal receiving device according to claim 1, characterized in that: The optical signal processing component comprises: An optical fiber beam splitter, adapted to split the echo signal into n signals of equal light intensity; n processing units, each processing unit is suitable for processing one signal on a one-to-one basis, and each processing unit includes: The optical fiber collimator is suitable for collimating a corresponding signal to obtain a collimated signal; An adjustable optical attenuator, adapted to adjust the intensity of the collimated signal; A filter, used for filtering the collimated signal to obtain the sub-echo signal; Among them, the filtering wavelengths of the filters of different processing units are different, and the filtering wavelengths of the n filters correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals, so that the n sub-echo signals obtained after filtering correspond one-to-one to the wavelengths of the n ultraviolet laser pulse signals.

7. The signal receiving device according to claim 6, characterized in that: The processing unit also includes: A galvanometer, adapted to change the propagation direction of the sub-echo signal output by the filter; The lens is suitable for focusing the sub-echo signal after the propagation direction is changed to the single-photon detector of the corresponding detection unit.

8. The signal receiving device according to claim 1, characterized in that: The data processing component includes: A time conversion unit, connected to the n detection units, adapted to determine the difference between the time when the detection unit outputs each digital trigger signal and the emission time of the ultraviolet laser pulse signal, and accumulate all the differences obtained according to the detection unit into time distribution histogram data; A correction unit, adapted to process the time distribution histogram data obtained according to each detection unit to reduce the influence of dark counts, afterpulses and dead time of the single-photon detector on the single-photon signal detection, and adapted to smooth 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 according to the time distribution data of the corrected single photon signal output by the n detection units.

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