Multi-component gas detection device and detection method

Abstract

The invention 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 characterized in that according to components of detected gas, a laser driver drives a laser array to emit light with different modulation frequencies and multiple wavelengths, the light is changed into parallel light after passing through an optical fiber array and a micro-lens array, and the parallel light is transmitted to a gas detector; after gas to be detected is absorbed and reflected by a diffuse reflection surface, reflected light passes through a lens and a dichroscope to be converged, light with long wavelength and light with short wavelength respectively enter photoelectric detectors with corresponding wave bands, the photoelectric detectors convert optical signals into electric signals and filter the electric signals, and the filtered signals to be detected are transmitted into a digital lock-in amplifier to be processed in parallel. And demodulating second harmonics and first harmonics of different gases, and calculating the concentration of each to-be-detected gas through a calculation unit. According to the invention, simultaneous detection of multi-component gas concentration can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas detection, and in particular relates to a multi-component gas detection device and a detection method. Background Art

[0002] Tunable laser absorption spectroscopy (TDLAS) has the advantages of high sensitivity, high response, high resolution, long instrument life, and non-contact detection. It has been widely used in many fields such as harmful gas detection, greenhouse gas emission measurement, and gas leakage monitoring. Most of the TDLAS detections currently on the market are single gas detection modes, and the application scenarios are limited. In the field of polluted gas detection, it is necessary to detect a variety of polluted 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 detections of flammable, explosive or toxic gases. For example, in the process of mineral resource mining, the mining environment is harsh, and a large amount of dangerous gases are always produced during the process. It is necessary to monitor the gases of different components in the mining environment, including oxygen, carbon monoxide, carbon dioxide, methane, ethylene, etc. During the production, storage and transportation of petroleum products, a large amount of flammable, explosive, toxic and harmful gases are generated, including a variety of low-boiling 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 pose a threat to the health of workers; on the other hand, if the amount of flammable and explosive gases entering the air exceeds a certain amount, an explosion will occur, causing 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, the simple use of single-component gas detection equipment will not only increase the measurement cost, but also be unfavorable for the expansion of application scenarios, such as being carried on unmanned equipment such as drones and inspection robots. Improving the integration of the TDLAS system and reducing the system volume, weight and other loads are the key to the system's adaptation to unmanned equipment. Fiber optic integration technology combined with micro-nano processing technology can effectively further improve the system's integration and reduce the system load.

[0004] At present, the main technical solutions for multi-component gas detection based on TDLAS multi-gas detection technology are wavelength division multiplexing (WDM), frequency division multiplexing (FDM) and time division multiplexing (TDM), but a single multiplexing technology is difficult to meet the actual application needs. The combined use of multiple multiplexing technologies is the key to solving the problem. The patent "A Methane and Ethane Dual Gas Detection Method and Device Based on TDLAS" (CN114965357) uses WDM technology to detect methane and ethane, and selects a 1680nm DFB laser beam to scan a wider wavelength range. This range can simultaneously cover the absorption spectra of methane and ethane to detect the two gases. The paper "Multi-component Trace Gas Identification and Detection Based on SVM and Near-infrared TDLAS Technology" (Fang Xiaomeng, Wang Hualai, Xu Hui, etc., Spectroscopy and Spectral Analysis, 2024) is based on FDM technology. Through a laser array and an eight-in-one fiber coupler, the detection light is coupled into an optical fiber to achieve the detection of eight gases such as NO and H2S in the near-infrared band. The paper "Research on Multi-component Gas Measurement Based on Laser Absorption Spectroscopy Frequency-Time Division Multiplexing Technology" (Shen Chenying, Wu Huakun, Wu Qiong, etc., Acta Optica Sinica, 2024) is based on the composite FDM and TDM technology. The detection light is coupled into an optical fiber through a four-in-one fiber coupler to achieve the detection of four gases C2H4, H2S, CH4, and H2O in the near-infrared band.

[0005] At present, the technical bottleneck that limits the further increase in the number of gas detections is the limitation of the detection light wavelength by optical fiber, fiber coupler, optical collimator, and photodetector. In order to improve the detection accuracy and stability of the system, the detection light needs to have good collimation, which requires the optical fiber to be single-mode output, but the near-infrared single-mode fiber is not single-mode output in the visible light range. The optical properties of the fiber coupler also have extremely high requirements on the wavelength range. Deviating from the designed center wavelength will lead to unstable optical properties. Due to the dispersion characteristics of the lens, the optical collimator will lead to a decrease in the collimation characteristics when the detection wavelength deviates from the designed center wavelength. Due to material limitations, photodetectors are difficult to cover the visible and near-infrared bands. Summary of the invention

[0006] The purpose of the present invention is to provide a multi-component gas detection device and detection method, which can realize the simultaneous detection of multi-component gas concentrations, realize multi-wavelength laser high-collimation output through optical fiber array + microlens array, improve system integration and stability, reduce system load, and enable the system to adapt to different carriers. Through dichroic mirror splitting, detection in the range of visible light to near-infrared light is realized, increasing the types of gases that the system can detect.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A multi-component gas detection device, comprising a laser array, an optical fiber array, a microlens array, 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;

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

[0010] The optical fiber array is connected to the laser array and is used to project detection lasers of multiple wavelengths onto the microlens array;

[0011] The microlens array is mounted on the front side of the optical fiber array and is used to convert detection lasers of multiple wavelengths into parallel detection lasers;

[0012] The focusing lens is used to converge the reflected light of the parallel detection laser after passing through the gas to be detected;

[0013] The dichroic mirror is used to separate 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, 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;

[0015] The processing unit is used to receive the analog electrical signal transmitted by the detector and filter the analog electrical signal;

[0016] 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 the first harmonic of different gases;

[0017] The calculation unit is used to calculate the concentration of each gas to be measured according to the second harmonic and the first harmonic of different gases.

[0018] Further, the laser array includes a plurality of lasers arranged in an array, and the plurality of lasers emit light of a plurality of wavelengths having different carrier frequencies;

[0019] The laser emitting 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.

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

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

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

[0023] Furthermore, the processing unit includes an amplifier circuit, a filter circuit and an ADC circuit, wherein 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.

[0024] Further, the digital lock-in amplifier includes a waveform generating device, a multiplier, a low-pass filter, and a D / A chip;

[0025] 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;

[0026] 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;

[0027] The low-pass filter is used to filter out the modulated high-frequency sinusoidal signal from the digital signal output by the multiplier;

[0028] 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.

[0029] Furthermore, the calculation unit may use a gas concentration inversion algorithm to calculate the concentration of each gas to be measured, and the inversion algorithm includes the following steps:

[0030] The half-width and half-height of the peaks and valleys of the first harmonic signal and the second harmonic signal 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, so that the measurement of multi-component gases can be completed simultaneously.

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

[0032] S1: The laser driving unit drives the laser array to emit detection lasers of multiple wavelengths with different modulation frequencies;

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

[0034] S3: After the parallel detection laser is absorbed by the gas to be measured, it is reflected by the background to form reflected light;

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

[0036] 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 to be transmitted to a processing unit;

[0037] S6: After the analog electrical signal passes through the processing unit, the electrical signal to be measured 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;

[0038] S7: Calculate the concentration of each gas to be measured by the calculation unit.

[0039] The technical effects achieved by the present invention are:

[0040] A multi-component gas detection device and detection method of the present invention realizes high-collimation output of multi-wavelength lasers through an optical fiber array + microlens array. Each microlens in the microlens array has different optical parameters for optical fibers with different parameters and laser wavelengths, thereby improving the collimation of the emission of detection lasers with different wavelengths, improving the system integration and stability, reducing the system load, and enabling the system to adapt to different carriers. Through dichroic mirror spectroscopy, the limited detection wavelength range of a single detector is compensated, and detection in the range of visible light to near-infrared light is realized, thereby increasing the types of gases that can be detected by the system. Therefore, the technical solution can realize simultaneous detection of multi-component gas concentrations through optical fiber array + microlens array technology and dichroic mirror spectroscopy technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is the overall flow chart of the system of the present invention;

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

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

[0044] Figure 4 It is a schematic diagram of the arrangement of the microlens array of the present invention.

[0045] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0046] 1. Optical fiber array; 2. Microlens array. DETAILED DESCRIPTION

[0047] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0048] Embodiment 1:

[0049] like Figure 1-4 As shown, a multi-component gas detection device includes 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. The FPGA control unit includes a laser driving unit, a processing unit, a digital lock-in amplifier, and a computing unit;

[0050] Wherein, the laser array is used to emit detection lasers of multiple wavelengths with different carrier frequencies;

[0051] Here, the laser array includes a plurality of lasers arranged in an array, and the plurality of lasers are matched with respective drivers to emit light of a plurality of wavelengths with different carrier frequencies.

[0052] Wherein, the laser driving unit is preferably a laser driver, the laser driving unit and the laser array are electrically connected, the laser driving unit is a device for controlling multiple lasers in the laser array, realizing temperature control, different modulation frequency control, and wavelength sweep control of the laser, so that the laser driving unit drives the laser array to emit detection lasers of multiple wavelengths with different modulation frequencies;

[0053] The laser drive unit includes a voltage-controlled constant current source and a PID temperature control system. The voltage-controlled constant current source can adjust the current and convert the modulated voltage signal into a current signal, adjust the laser wavelength in small amplitudes, and load different carrier frequencies to the laser output. The PID temperature control system adjusts the temperature to keep the laser operating temperature stable and reduce the impact of temperature on the laser output wavelength.

[0054] Moreover, when the number of laser driving units is one, the laser driving unit and multiple lasers are arranged in parallel, which can realize independent control of each laser, and the number of lasers turned on can be controlled according to detection requirements, saving system resources and improving detection efficiency.

[0055] When there are multiple laser driving units, the multiple laser driving units are electrically connected to the multiple lasers independently, so that each laser can be controlled independently. The number of lasers turned on can be controlled according to the detection requirements, thus saving system resources and improving detection efficiency.

[0056] The optical fiber array 1 is connected to the laser array to project detection lasers of multiple wavelengths onto the microlens array 2;

[0057] The laser transmitting end is connected with a single-mode optical fiber. The number of single-mode optical fibers and lasers is the same. The mode field diameters of the multiple single-mode optical fibers are different, so that the optical properties of the multiple single-mode optical fibers are different. Different detection wavelengths correspond to single-mode optical fibers with different optical properties.

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

[0059] The ends of multiple 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 any two-dimensional surface distribution such as square arrangement, circular arrangement, hexagonal honeycomb arrangement, etc.;

[0060] At least one of the lasers outputs continuous visible light, so that one of the single-mode optical fibers outputs continuous visible light, which is used to indicate the detection path; the remaining lasers output detection lasers, so that the remaining single-mode optical fibers output detection lasers. The output laser quantity can be controlled according to demand, saving system resources and improving efficiency.

[0061] The microlens array 2 is installed on the front side of the optical fiber array 1 and is used to convert the detection lasers of multiple wavelengths into parallel detection lasers;

[0062] The microlens array 2 includes a plurality of microlenses, each of which has different optical parameters according to the single-mode optical fiber parameters and the detection laser wavelength, so as to improve the emission collimation of the detection lasers of different wavelengths, thereby improving the detection distance, detection accuracy and system stability, so that the detection lasers of different wavelengths have good collimation, improve the system performance and integration, and reduce the system load.

[0063] A plurality of micro lenses are respectively installed in front of a plurality of single-mode optical fibers, so that a micro lens is installed in front of each single-mode optical fiber, and the micro lens converts the detection laser emitted by each single-mode optical fiber into a parallel detection laser.

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

[0065] The focusing lens is used to converge the reflected light of the parallel detection laser after passing through the gas to be detected.

[0066] Among them, the dichroic mirror is used to separate the converged reflected light into long-wavelength light and short-wavelength light;

[0067] Due to material limitations, the detection wavelength range of a single detector is limited. The detection signal is divided into two long and short wavelengths through a dichroic mirror, and received by detectors of different wavelengths respectively, thus realizing detection from the visible light band to the near-infrared band.

[0068] Among them, the two detectors are photoelectric detectors corresponding to the long-wavelength light and short-wavelength light bands, namely the long-wave detector and the short-wave detector. The long-wave detector and the short-wave detector are respectively used to receive the long-wavelength light signal and the short-wavelength light signal carrying the gas concentration information, and convert the light signal into an analog electrical signal and transmit it to the processing unit.

[0069] The processing unit is used to receive the analog electrical signal transmitted by the detector and filter the analog electrical signal.

[0070] Specifically, the processing unit includes an amplifier circuit, a filter circuit and an ADC circuit. The amplifier circuit is used to amplify the weak 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.

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

[0072] Among them, 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;

[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 to generate a low-frequency driving sawtooth wave and a high-frequency regulating sine wave. The low-frequency driving sawtooth wave can be output to external devices such as a laser driving unit; the high-frequency regulating sine wave is used as a reference signal to provide a benchmark for subsequent signal processing of the digital phase-locked amplifier.

[0075] 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;

[0076] The low-pass filter is used to filter out the modulated high-frequency sinusoidal signal from the digital signal output by the multiplier;

[0077] 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 first harmonic of each gas.

[0078] The calculation unit is used to calculate the concentration of each gas to be measured according to the second harmonic and the first harmonic of different gases.

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

[0080] The half-width and half-height of the peaks and valleys of the first harmonic signal and the second harmonic signal 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, so that the measurement of multi-component gases can be completed simultaneously.

[0081] In summary, the technical solution realizes high-collimation output of multi-wavelength lasers through the optical fiber array 1 + microlens array 2. Each microlens in the microlens array 2 has different optical parameters for optical fibers with different parameters and laser wavelengths, thereby improving the collimation of the emission of detection lasers with different wavelengths, improving the system integration and stability, reducing the system load, and enabling the system to adapt to different carriers. Through dichroic mirror spectroscopy, the limited detection wavelength range of a single detector is compensated, and detection in the range of visible light to near-infrared light is realized, thereby increasing the types of gases that can be detected by the system. Therefore, the technical solution can realize simultaneous detection of multi-component gas concentrations through the optical fiber array 1 + microlens array 2 technology and dichroic mirror spectroscopy technology.

[0082] Embodiment 2:

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

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

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

[0086] S3: The parallel detection laser is absorbed by the gas to be measured in the telemetry environment and then reflected by the background to form reflected light;

[0087] S4: The reflected light is converged by the focusing lens and then separated into long wavelength light and short wavelength light of different wavelength ranges by the dichroic mirror;

[0088] 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 to be transmitted to a processing unit;

[0089] S6: After the analog electrical signal passes through the processing unit, the electrical signal to be measured 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;

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

[0091] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A multi-component gas detection device, characterized in that: It 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 installed 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 detected; 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 the first harmonic of different gases; The calculation unit is used to calculate the concentration of each gas to be measured according to 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 a plurality of wavelengths having 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. A 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, and the inversion algorithm includes the following steps: The half-width and half-height of the peaks and valleys of the first harmonic signal and the second harmonic signal 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 gases.

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 converged 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 to be transmitted to a processing unit; S6: After the analog electrical signal passes through the processing unit, the electrical signal to be measured 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 by the calculation unit.

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