Multi-component gas detection device and detection method

Abstract

The application belongs to the technical field of gas detection, and particularly relates to a multi-component gas detection device and a detection method. The multi-component gas detection device is driven by a laser driver to emit light with different modulation frequencies and multiple wavelengths from a laser array according to the components of the detected gas. After passing through an optical fiber array and a micro-lens array, the light becomes parallel light. After being absorbed by the detected gas, the light is reflected by a diffuse reflection surface. After converging through a lens and passing through a dichroic mirror, the light with long and short wavelengths is respectively injected into photoelectric detectors corresponding to the wave bands. The photoelectric detectors convert the light signals into electric signals and perform filtering. After filtering, the detected signals are transmitted into a digital lock-in amplifier for parallel processing. The second harmonic and the first harmonic of different gases are demodulated, and the concentration of each detected gas is calculated by a calculation unit. The application can realize simultaneous detection of the concentrations of multi-component gases.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas detection, and particularly relates to a multi-component gas detection device and a detection method. BACKGROUND

[0002] Tunable diode laser absorption spectroscopy (TDLAS) has the advantages of high sensitivity, high response, high resolution, long service life of the instrument, and non-contact detection. It has been widely used in harmful gas detection, greenhouse gas emission measurement, and gas leakage monitoring, etc. The current market TDLAS detection is mostly single gas detection mode, which has limited application scenarios. In the field of pollution gas detection, it is necessary to detect multiple pollution gases, such as carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ammonia (NH3), hydrogen sulfide (H2S), etc. In the field of greenhouse gas measurement, water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), freon, and methane (CH4) are the main greenhouse gases in the earth's atmosphere. In the field of gas leakage, most of them are detection of flammable and explosive or toxic gases. For example, in the process of mining mineral resources, the mining environment is poor, and a large amount of dangerous gas will be generated during the process, which needs to monitor the different components of the gas in the mining environment, including oxygen, carbon monoxide, carbon dioxide, methane, ethylene, etc. In the process of oil industry product production, storage and transportation, a large amount of flammable, explosive, toxic and harmful gases will be generated, including a variety of low-boiling-point and volatile gases, including methane, ethane, propane, carbon dioxide, ethylene, propylene, etc. On the one hand, toxic and harmful gases entering the air cause environmental pollution, and at the same time pose a threat to the health of workers; on the other hand, flammable and explosive gases entering the air will exceed a certain amount and cause explosions, resulting in serious production safety accidents and huge personal and property losses.

[0003] In view of the application requirements of multi-component gas detection in different scenarios, simply stacking single-component gas detection equipment not only causes the rise of measurement cost, but also is not conducive to the expansion of application scenarios, such as being carried on unmanned equipment such as unmanned aerial vehicles and inspection robots. Improving the integration of the TDLAS system, reducing the system volume and weight, etc. is the key to adapting the system to unmanned equipment. Fiber integration technology combined with micro-nano processing technology can effectively further improve the integration of the system and reduce the system load.

[0004] The main technical solutions for realizing multi-component gas detection based on TDLAS are wavelength division multiplexing (WDM), frequency division multiplexing (FDM), and time division multiplexing (TDM). However, single multiplexing technology cannot meet the actual application requirements, and the combined use of multiple multiplexing technologies is the key to solving the problem. In the patent "Methane and ethane dual-gas detection method and device based on TDLAS" (CN114965357), WDM technology is used to detect methane and ethane. A DFB laser beam with a wavelength of 1680 nm is selected to scan a wide wavelength range, which can simultaneously cover the absorption spectral lines of methane and ethane, realizing the detection of the two gases. In the paper "Multi-component trace gas identification and detection based on SVM and near-infrared TDLAS technology" (Fang Xiaomeng, Wang Hualai, Xu Hui, et al., Spectroscopy and Spectral Analysis, 2024), FDM technology is used. A laser array and an eight-in-one fiber coupler are used to couple the probe light into a single optical fiber, realizing the detection of eight gases such as NO and H2S in the near-infrared wavelength range. In the paper "Multi-component gas measurement research based on laser absorption spectrum frequency-time division multiplexing technology" (Shen Chenying, Wu Huakun, Wu Qiong, et al., Acta Optica Sinica, 2024), FDM and TDM technologies are combined. A four-in-one fiber coupler is used to couple the probe light into a single optical fiber, realizing the detection of four gases such as C2H4, H2S, CH4, and H2O in the near-infrared wavelength range.

[0005] The technical bottleneck that limits the further increase of the number of gas detection is the limitation of the wavelength of the probe light by the optical fiber, fiber coupler, optical collimation device, and photodetector. To improve the detection accuracy and stability of the system, the probe light needs to have good collimation, which requires the optical fiber to be single-mode output. However, near-infrared single-mode optical fibers are not single-mode output in the visible light range. The optical properties of the fiber coupler also have high requirements for the wavelength range. Deviation from the design center wavelength will lead to instability of the optical properties. Due to the dispersion characteristics of the lens, when the detection wavelength deviates from the design center wavelength, the collimation characteristics will decrease. Due to material limitations, photodetectors are difficult to cover the visible and near-infrared wavelength ranges. SUMMARY

[0006] The purpose of the present application is to provide a multi-component gas detection device and method that can realize the simultaneous detection of multi-component gas concentration. The use of a fiber array + microlens array realizes high collimation output of multi-wavelength laser, improves the system integration and stability, reduces the system load, and makes the system adaptable to different carriers. Through dichroic mirror splitting, detection in the visible light to near-infrared light range is realized, and the number of detectable gas types is increased.

[0007] The technical solutions adopted by the present application are as follows:

[0008] A multi-component gas detection device, comprising a laser array, a fiber array, a microlens array, a focusing lens, a dichroic mirror, two detectors, an FPGA control unit, the FPGA control unit comprising a laser driving unit, a processing unit, a digital lock-in amplifier, a calculation unit;

[0009] The laser driving unit is electrically connected with the laser array, and the laser driving unit drives the laser array to emit detection laser beams of multiple wavelengths with different modulation frequencies.

[0010] The fiber array is connected with the laser array, and is used for projecting the detection laser beams of multiple wavelengths to the microlens array.

[0011] The microlens array is installed on the front side of the fiber array, and is used for converting the detection laser beams of multiple wavelengths into parallel detection laser beams.

[0012] The focusing lens is used for converging reflected light reflected after the parallel detection laser beams pass through the gas to be detected.

[0013] The dichroic mirror is used for dividing the converged reflected light into long-wavelength light and short-wavelength light.

[0014] The two detectors are respectively a long-wave detector and a short-wave detector, and are respectively used for receiving long-wavelength light signals and short-wavelength light signals, and converting the light signals into analog electric signals and transmitting the analog electric signals to the processing unit.

[0015] The processing unit is used for receiving the analog electric signals transmitted by the detectors, and filtering the analog electric signals.

[0016] The digital lock-in amplifier is used for processing the filtered electric signals, and demodulating the filtered electric signals to obtain second harmonics and first harmonics of different gases.

[0017] The calculation unit is used for calculating the concentration of each gas to be detected according to the second harmonics and the first harmonics of different gases.

[0018] Further, the laser array comprises a plurality of arrayed lasers, and the plurality of lasers emit light of multiple wavelengths with different carrier frequencies.

[0019] The laser emitting end is connected with a single-mode fiber, the number of the single-mode fibers is the same as that of the lasers, the optical properties of the plurality of single-mode fibers are different, and the ends of the plurality of single-mode fibers form the fiber array.

[0020] Further, the arrangement shape of the ends of the single-mode fibers is any one of a square arrangement, a circular arrangement, and a hexagonal honeycomb arrangement.

[0021] Further, at least one of the lasers outputs continuous visible light.

[0022] Further, the microlens array comprises a plurality of microlenses with different optical parameters, and the plurality of microlenses are respectively arranged in front of the plurality of single-mode optical fibers.

[0023] Further, the processing unit comprises an amplification circuit, a filter circuit and an ADC circuit, the amplification circuit is used for amplifying the analog electrical signal received from the detector; the filter circuit is used for filtering out the noise in the analog electrical signal; and the ADC circuit is used for converting the analog electrical signal into a digital signal.

[0024] Further, the digital phase-locked amplifier comprises a waveform generating device, a multiplier, a low-pass filter and a D / A chip.

[0025] The waveform generating device is used for generating a low-frequency driving sawtooth wave and a high-frequency adjusting sinusoidal wave, the low-frequency driving sawtooth wave is output to the laser driver unit, and the high-frequency adjusting sinusoidal wave is used as a reference signal.

[0026] The multiplier is used for multiplying the electrical signal to be measured and the reference signal, so that the low-frequency direct current part of the signal only contains a digital signal with concentration information.

[0027] The low-pass filter is used for filtering out the modulated high-frequency sinusoidal signal in the digital signal output by the multiplier.

[0028] The D / A chip is used for converting the digital signal processed by the low-pass filter into an analog signal, and outputting the second harmonic and the first harmonic of each gas.

[0029] Further, the calculation unit can calculate the concentration of each gas to be measured by using a gas concentration inversion algorithm, and the inversion algorithm comprises the following steps.

[0030] The half-width and half-height of the peak-to-valley of the first harmonic signal and the second harmonic signal demodulated by the phase-locked amplifier are fitted with the concentration, and the correlation coefficient of the half-width and half-height value and the concentration of the gas to be measured is calculated, so that the measurement of the multi-component gas can be completed at the same time.

[0031] A multi-component gas detection method comprises the following steps.

[0032] S1: The laser driver unit drives the laser array to emit a plurality of wavelengths of probe laser with different modulation frequencies;

[0033] S2: The probe laser is converted into parallel probe laser by the optical fiber array and the microlens array;

[0034] S3: After the parallel probe laser passes through the gas to be measured and is reflected by the background, the reflected light is formed;

[0035] S4: the reflected light is converged by the focusing lens and is separated into long-wavelength light and short-wavelength light of different wavelength ranges by a dichroic mirror;

[0036] S5: the long-wavelength light signal and the short-wavelength light signal are received by two detectors of different wavelength ranges, and the light signals are converted into analog electric signals and transmitted to a processing unit;

[0037] S6: after the analog electric signals pass through the processing unit, the to-be-detected electric signals and reference signals are transmitted into a phase-locked amplifier and processed in parallel, and the second harmonics and the first harmonics of multiple gases are demodulated;

[0038] S7: the concentration of each to-be-detected gas is calculated by a calculation unit.

[0039] The technical effects achieved by the application are as follows:

[0040] The multi-component gas detection device and the detection method achieve high collimation output of multi-wavelength laser through a fiber array + a microlens array. Each microlens in the microlens array has different optical parameters for different parameter optical fibers and wavelength lasers, improves the collimation of the outgoing detection laser of different wavelengths, improves the system integration and stability, reduces the system load, so that the system can adapt to different carriers. The dichroic mirror splits light, compensates for the limited detection wavelength range of a single detector, realizes detection in the visible light to near-infrared light range, improves the types of detectable gases, and thus the technical scheme can realize simultaneous detection of the concentrations of multiple-component gases through the fiber array + microlens array technology and the dichroic mirror splitting technology. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is the system overall flowchart of the application;

[0042] Figure 2 is a schematic diagram of the fiber array and the microlens of the application;

[0043] Figure 3 is a side view of the fiber array and the microlens of the application;

[0044] Figure 4 is a schematic diagram of the microlens array arrangement of the application.

[0045] In the drawings, the components represented by the numbers are listed as follows:

[0046] 1, fiber array; 2, microlens array. DETAILED DESCRIPTION

[0047] In order to make the purposes and advantages of the present application more clear and understandable, the present application is specifically described below in conjunction with embodiments. It should be understood that the following description is merely used to describe one or several specific embodiments of the present application and does not strictly limit the scope of protection specifically requested by the present application.

[0048] Embodiment 1

[0049] As shown in Figures 1-4 A multi-component gas detection device, comprising a laser array, a fiber array 1, a microlens array 2, a focusing lens, a dichroic mirror, two detectors, an FPGA control unit, the FPGA control unit comprising a laser driver unit, a processing unit, a digital lock-in amplifier, a calculation unit;

[0050] The laser array is used to emit detection laser beams of multiple wavelengths with different carrier frequencies.

[0051] The laser array comprises a plurality of arrayed lasers, and the plurality of lasers emit light of multiple wavelengths with different carrier frequencies under the matching of respective drivers.

[0052] The laser driver unit is preferably a laser driver, the laser driver unit is electrically connected with the laser array, and the laser driver unit is a device for controlling the plurality of lasers of the laser array, achieving temperature control, different modulation frequency control, and wavelength sweep frequency control of the lasers, so that the laser driver unit drives the laser array to emit detection laser beams of multiple wavelengths with different modulation frequencies.

[0053] The laser driver unit comprises a voltage-controlled constant current source and a PID temperature control system. The voltage-controlled constant current source can convert a modulation voltage signal into a current signal by adjusting the current, and can adjust the wavelength of the laser in a small range and load different carrier frequencies to the output of the laser. The PID temperature control system keeps the working temperature of the laser stable by adjusting the temperature, and reduces the influence of temperature on the output wavelength of the laser.

[0054] When the number of laser driver units is one, the laser driver unit and the plurality of lasers are connected in parallel, and independent control of each laser can be achieved. The number of lasers to be turned on can be controlled according to the detection requirements, system resources can be saved, and detection efficiency can be improved.

[0055] When the number of laser driver units is multiple, the plurality of laser driver units are independently electrically connected with the plurality of lasers, and independent control of each laser can be achieved. The number of lasers to be turned on can be controlled according to the detection requirements, system resources can be saved, and detection efficiency can be improved.

[0056] The fiber array 1 is connected with the laser array and is used to project the detection laser beams of multiple wavelengths onto the microlens array 2.

[0057] The laser emission end is connected with single-mode optical fibers, the number of single-mode optical fibers is the same as that of the lasers, the mode field diameters of the plurality of single-mode optical fibers are different, so that the optical properties of the plurality of single-mode optical fibers are different, and different probe wavelengths correspond to different optical properties of the single-mode optical fibers;

[0058] The optical fiber selects single-mode optical fibers with different mode field diameters according to different probe laser wavelengths, so as to ensure single-mode output of each wavelength light.

[0059] The ends of the plurality of single-mode optical fibers form an optical fiber array 1, and the arrangement shape of the ends of the single-mode optical fibers can be a square arrangement, a circular arrangement, a hexagonal honeycomb arrangement or any two-dimensional surface distribution.

[0060] At least one of the lasers outputs continuous visible light, so that one of the single-mode optical fibers outputs the continuous visible light, which is used for indicating a probe path; the remaining lasers output probe lasers, so that the remaining single-mode optical fibers output the probe lasers, and the number of output lasers can be controlled according to requirements, system resources are saved, and efficiency is improved.

[0061] The microlens array 2 is installed on the front side of the optical fiber array 1, and is used for converting the probe lasers of multiple wavelengths into parallel probe lasers.

[0062] The microlens array 2 includes a plurality of microlenses, each microlens has different optical parameters according to different single-mode optical fiber parameters and probe laser wavelengths, the emission collimation of the probe lasers of different wavelengths is improved, and then the probe distance, the probe precision and the system stability are improved, so that the probe lasers of different wavelengths all have good collimation, the system performance and the integration are improved, and the system load is reduced.

[0063] The plurality of microlenses are respectively installed on the front sides of the plurality of single-mode optical fibers, so that each single-mode optical fiber is provided with a microlens in front, and the microlens changes the probe laser emitted by each single-mode optical fiber into parallel probe laser.

[0064] The optical fiber array 1+microlens array 2 can realize collimated emission of probe lasers of different wavelengths, and improve the system integration.

[0065] The focusing lens is used for converging the reflected light reflected after the parallel probe laser passes through the gas to be measured.

[0066] The dichroic mirror is used for dividing the converged reflected light into long-wavelength light and short-wavelength light.

[0067] Due to material limitations, the wavelength range of a single detector is limited, the probe signals are divided into two paths of long and short wavelengths by the dichroic mirror, different waveband detectors are used for receiving, and the probe from the visible light waveband to the near-infrared waveband is realized.

[0068] The two detectors are photoelectric detectors corresponding to long-wavelength light and short-wavelength light bands, namely a long-wave detector and a short-wave detector, and the long-wave detector and the short-wave detector are respectively used for receiving long-wavelength light signals and short-wavelength light signals carrying gas concentration information and converting the light signals into analog electric signals and transmitting the analog electric signals to the processing unit.

[0069] The processing unit is used for receiving the analog electric signals transmitted by the detectors and filtering the analog electric signals.

[0070] Specifically, the processing unit includes an amplification circuit, a filtering circuit and an ADC circuit, the amplification circuit is used for amplifying weak analog electric signals received from the detectors, the filtering circuit is used for filtering noise in the analog electric signals, and the ADC circuit is used for converting the analog electric signals into digital signals.

[0071] Here, the ADC circuit can be an AD chip.

[0072] The digital lock-in amplifier is used for processing the filtered electric signals and demodulating second harmonics and first harmonics of different gases from the filtered electric signals.

[0073] The digital lock-in amplifier includes a waveform generating device, a multiplier, a low-pass filter and a D / A chip.

[0074] The waveform generating device is used for generating a low-frequency driving sawtooth wave and a high-frequency adjusting sinusoidal wave, the low-frequency driving sawtooth wave can be output to external devices such as a laser driver unit, and the high-frequency adjusting sinusoidal wave is used as a reference signal to provide a reference for subsequent signal processing of the digital lock-in amplifier.

[0075] The multiplier multiplies the to-be-detected electric signals with the reference signal, so that the low-frequency direct current part of the signals only contains digital signals with concentration information.

[0076] The low-pass filter is used for filtering the digital signals output by the multiplier to remove the modulated high-frequency sinusoidal signals.

[0077] The D / A chip is used for converting the digital signals processed by the low-pass filter into analog signals and outputting second harmonics and first harmonics of each gas.

[0078] The calculation unit is used for calculating the concentration of each to-be-detected gas according to the second harmonics and the first harmonics of different gases.

[0079] Here, the calculation unit can use a gas concentration inversion algorithm to calculate the concentration of each to-be-detected gas, and the inversion algorithm includes the following steps:

[0080] The half-width and half-height of the peak-to-valley of the first harmonic signal and the second harmonic signal demodulated by the phase-locked amplifier are fitted with the concentration, the correlation coefficient of the half-width and half-height value and the concentration of the to-be-measured gas is calculated, and the measurement of multiple-component gas can be completed at the same time.

[0081] In summary, the technical scheme realizes high-collimation output of multi-wavelength laser through the fiber array 1+microlens array 2, each microlens in the microlens array 2 has different optical parameters for different parameter optical fibers and wavelength lasers, the collimation of the outgoing detection laser of different wavelengths is improved, the system integration and stability are improved, the system load is reduced, the system can adapt to different carriers, the limited detection wavelength range of a single detector is compensated through dichroic mirror splitting, the detection in the visible light to near-infrared light range is realized, the types of detectable gases are improved, and thus the technical scheme can realize simultaneous detection of multi-component gas concentration through the fiber array 1+microlens array 2 technology and dichroic mirror splitting technology.

[0082] Embodiment 2:

[0083] As shown in Figures 1-4 the embodiment discloses a multi-component gas detection method based on the embodiment 1, comprising the following steps:

[0084] S1: the laser driver unit drives the laser array to emit detection laser of multiple wavelengths with different modulation frequencies;

[0085] S2: the detection laser passes through the fiber array 1 composed of different single-mode optical fibers, and the microlens array 2 composed of microlenses with corresponding parameters is matched in front of the fiber array 1 to convert the detection laser into parallel detection laser;

[0086] S3: after the parallel detection laser passes through the to-be-measured gas in the remote measurement environment and is reflected by the background, reflected light is formed;

[0087] S4: the reflected light is focused by the focusing lens and is split into long-wavelength light and short-wavelength light of different wavelength ranges by the dichroic mirror;

[0088] S5: two detectors with different wavelength ranges are used to receive the long-wavelength light signal and the short-wavelength light signal, and the light signals are converted into analog electric signals and transmitted to the processing unit;

[0089] S6: after the analog electric signals pass through the processing unit, the to-be-measured electric signals and the reference signals are transmitted into the phase-locked amplifier and processed in parallel, and the second harmonic and the first harmonic of multiple gases are demodulated at the same time;

[0090] S7: the concentration of each to-be-measured gas is calculated by the calculation unit.

[0091] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application. The structures, devices and operation methods not specifically described and explained in the present application are implemented according to the conventional means in the art, unless specifically described and limited.

Claims

1. A multi-component gas detection device, characterized in that: The system comprises a laser array, an optical fiber array (1), a microlens array (2), a focusing lens, a dichroic mirror, two detectors, and an FPGA control unit, wherein the FPGA control unit comprises a laser driving unit, a processing unit, a digital lock-in amplifier, and a computing unit; The laser driving unit drives the laser array to emit detection lasers of multiple wavelengths with different modulation frequencies; The optical fiber array (1) is connected to the laser array and is used to project detection lasers of multiple wavelengths onto the microlens array (2); The microlens array (2) is mounted on the front side of the optical fiber array (1) and is used to convert detection lasers of multiple wavelengths into parallel detection lasers; The focusing lens is used to converge the reflected light of the parallel detection laser after passing through the gas to be measured; The dichroic mirror is used to separate the converged reflected light into long-wavelength light and short-wavelength light; The two detectors are respectively a long-wave detector and a short-wave detector, which are used to receive long-wavelength optical signals and short-wavelength optical signals respectively, and convert the optical signals into analog electrical signals and transmit them to the processing unit; The processing unit is used to receive the analog electrical signal transmitted by the detector and filter the analog electrical signal; The digital lock-in amplifier is used to process the filtered electrical signal and demodulate the filtered electrical signal to obtain the second harmonic and first harmonic of different gases; The calculation unit is used to calculate the concentration of each gas to be measured based on the second harmonic and the first harmonic of different gases.

2. A multi-component gas detection device and detection method according to claim 1, characterized in that: The laser array includes a plurality of lasers arranged in an array, wherein the plurality of lasers emit light of multiple wavelengths with different carrier frequencies; The laser emission end is connected to a single-mode optical fiber, the number of the single-mode optical fibers is the same as the number of lasers, the optical properties of the multiple single-mode optical fibers are different, and the ends of the multiple single-mode optical fibers form an optical fiber array (1).

3. A multi-component gas detection device and detection method according to claim 2, characterized in that: The arrangement shape of the single-mode optical fiber ends is any one of a square arrangement, a circular arrangement, and a hexagonal honeycomb arrangement.

4. A multi-component gas detection device and detection method according to claim 1, characterized in that: At least one of the lasers outputs continuous visible light.

5. A multi-component gas detection device and detection method according to claim 2, characterized in that: The microlens array (2) comprises a plurality of microlenses with different optical parameters, and the plurality of microlenses are respectively mounted on the front sides of a plurality of single-mode optical fibers.

6. A multi-component gas detection device and detection method according to claim 1, characterized in that: The processing unit includes an amplifier circuit, a filter circuit and an ADC circuit. The amplifier circuit is used to amplify the analog electrical signal received from the detector; the filter circuit is used to filter out noise in the analog electrical signal; and the ADC circuit is used to convert the analog electrical signal into a digital signal.

7. A multi-component gas detection device and detection method according to claim 1, characterized in that: The digital lock-in amplifier includes a waveform generating device, a multiplier, a low-pass filter, and a D / A chip; The waveform generating device is used to generate a low-frequency driving sawtooth wave and a high-frequency regulating sine wave, wherein the low-frequency driving sawtooth wave is output to the laser driving unit; and the high-frequency regulating sine wave is used as a reference signal; The multiplier multiplies the electrical signal to be measured with the reference signal so that the low-frequency DC part of the signal only contains the digital signal with concentration information; The low-pass filter is used to filter out the modulated high-frequency sinusoidal signal from the digital signal output by the multiplier; The D / A chip is used to convert the digital signal processed by the low-pass filter into an analog signal, and output the second harmonic and the first harmonic of each gas.

8. The multi-component gas detection device and detection method according to claim 1, characterized in that: The calculation unit calculates the concentration of each gas to be measured using a gas concentration inversion algorithm, wherein the inversion algorithm comprises the following steps: The half-width and half-height of the peaks and valleys of the first and second harmonic signals demodulated by the lock-in amplifier are fitted with the concentration, and the correlation coefficient between the half-width and half-height value and the concentration of the gas to be measured is calculated to complete the measurement of multi-component gas.

9. A multi-component gas detection method, using a multi-component gas detection device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: The laser driving unit drives the laser array to emit detection lasers of multiple wavelengths with different modulation frequencies; S2: The detection laser is converted into parallel detection laser through the optical fiber array (1) and the microlens array (2); S3: After the parallel detection laser is absorbed by the gas to be measured, it is reflected by the background to form reflected light; S4: The reflected light is focused by the focusing lens and then separated into long wavelength light and short wavelength light of different wavelength ranges by the dichroic mirror; S5: using two detectors with different wavelength ranges to receive long-wavelength optical signals and short-wavelength optical signals, and converting the optical signals into analog electrical signals and transmitting them to the processing unit; S6: After the analog electrical signal passes through the processing unit, the measured electrical signal and the reference signal are transmitted to the phase-locked amplifier for parallel processing, and the second harmonics and first harmonics of multiple gases are demodulated at the same time; S7: Calculate the concentration of each gas to be measured through the calculation unit.

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