A rapid temperature measurement method and device based on micro-chamber double-absorption spectrum

Abstract

A rapid temperature measurement method and device based on dual absorption spectra of a micro-cell belongs to the field of laser absorption spectrum sensing. The device of this invention includes a light source module, a linear sweep frequency control module, a temperature measurement module, and a signal acquisition and temperature calculation module. This invention utilizes a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to ensure the linearity of the optical sweep frequency. Two absorption spectra with known frequency differences and carrying temperature information are generated by an acousto-optic modulator. Based on the time difference of the same absorption peak on the two absorption spectra with fixed frequency differences in the time domain, corresponding to the acousto-optic modulator driving frequency, i.e., ΔT = T1 - T2 corresponds to the acousto-optic modulator driving frequency f, the absorption spectrum is mapped from the time domain to the frequency domain. Then, the temperature of the cell is calculated by extracting temperature-related parameters from the frequency domain absorption spectrum. This invention solves the complex problems of traditional Doppler broadening temperature measurement systems and has advantages such as small measurement volume, low cost, high speed, high stability, and strong adaptability.

Description

Technical Field

[0001] This invention belongs to the field of laser absorption spectrum sensing, and relates to a rapid optical temperature measurement method and device based on micro-cell laser absorption spectrum. Background Technology

[0002] The analyte absorbs light of different specific wavelengths to form a laser absorption spectrum. These absorption lines carry information about the analyte; for example, a gas absorption spectrum contains state information such as temperature, pressure, flow rate, and concentration. This characteristic makes laser absorption spectroscopy widely used in sensing fields, such as trace detection, component analysis, and temperature sensing. Gas absorption spectroscopy-based sensing systems offer significant advantages, including high resolution, high sensitivity, and non-contact measurement. Therefore, laser absorption spectroscopy, with its unique advantages, demonstrates enormous potential for development in the sensing field.

[0003] Temperature measurement technology based on laser absorption spectroscopy is gradually replacing traditional temperature sensors to enable applications in more fields and extreme environments. Currently, there are two methods for temperature measurement based on laser absorption spectroscopy: the spectral line intensity method and the spectral linewidth method. The former is easily affected by the external environment, reducing measurement accuracy. The latter traces temperature measurement back to time and frequency quantities, has higher accuracy, requires no calibration, can achieve primary temperature measurement, and has a wide range of application prospects.

[0004] However, the main challenge of temperature measurement methods based on spectral linewidth lies in the need for precise control of the spectral line sweep interval or calibration of the absorption peak's full width at half maximum (FWHM). To obtain the absorption spectrum, the laser needs to be manipulated to achieve optical frequency sweeping. Typically, the output wavelength of a semiconductor laser is not strictly linearly related to the input signal; therefore, high-precision etalons such as ultrastable cavities and wavelength meters are required to control or monitor the spectral line sweeping process. While this method offers high accuracy, it suffers from drawbacks such as system complexity, long measurement time, large size, and expensive etalons, making miniaturization and practical application difficult. Currently, there is no rapid measurement or practical solution for temperature measurement methods based on spectral linewidth. Summary of the Invention

[0005] The purpose of this invention is to provide a rapid temperature measurement method and device based on dual absorption spectra of a micro-cell. It utilizes a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to ensure optical frequency sweep linearity. An acousto-optic modulator generates two absorption spectra with a known frequency difference, each carrying temperature information. Since the time difference between the same absorption peak on the two absorption spectra with a fixed frequency difference in the time domain equals the driving frequency of the acousto-optic modulator (ΔT = T1 - T2 corresponds to the driving frequency f), the absorption spectra are mapped from the time domain to the frequency domain. The temperature of the cell is then calculated by extracting temperature-related parameters from the frequency domain absorption spectrum. This invention solves the complex problems of traditional Doppler broadening temperature measurement systems and has advantages such as small measurement volume, low cost, high speed, high stability, and strong adaptability.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention discloses a rapid temperature measurement device based on micro-cell dual absorption spectra, comprising a light source module, a linear sweep frequency control module, a temperature measurement module, and a signal acquisition and temperature calculation module. The light source module provides a narrow-linewidth-wide-tuned sweep frequency laser. The linear sweep frequency control module achieves optical linear sweep frequency based on a scanning source, a fiber optic Mach-Zehnder interferometer, and a control circuit. The temperature measurement module generates two micro-cell absorption spectrum signals carrying temperature information through an acousto-optic modulator. The data acquisition and temperature calculation module acquires the two absorption spectra and calculates the temperature of the cell based on them.

[0008] The light source module outputs two beams, which simultaneously enter the linear sweep frequency control module and the temperature measurement module, respectively. The linear sweep frequency control module utilizes a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to control the output light from the light source module to achieve linear frequency sweeping. The scanning source outputs a sawtooth wave, causing the light source module's output light to cover the absorption lines of atoms or molecules. After entering the fiber optic Mach-Zehnder interferometer, the light source module's output light is split into two paths: one via a fiber optic jumper and the other via a delay fiber. These two paths converge and beat in the detector to generate a linear sweep frequency correction signal. The feedback control circuit stabilizes the beat signal, ensuring linear optical frequency output during the sweep process. The injected current and output optical frequency during sawtooth wave sweeping are non-linear; the scanning source, fiber optic Mach-Zehnder interferometer, and feedback control circuit significantly improve the optical frequency linearity during the sweep process. The temperature measurement module uses an acousto-optic modulator to generate two absorption spectrum signals with known frequency differences that are temperature-dependent. The time interval between the appearance of the same absorption peak in the two absorption spectra corresponds to the acousto-optic modulator's driving frequency f. By combining the linear sweep frequency control module and the temperature measurement module, and ensuring that the output light of the light source module achieves linear sweep frequency, the absorption spectrum signal frequency is calibrated based on the principle that the time difference between the same peak on two absorption spectrum lines corresponds to the driving frequency, i.e., ΔT = T1 - T2 corresponds to the acousto-optic modulator driving frequency f. This allows for the mapping of the absorption spectrum from the time domain to the frequency domain. The process of mapping from the time domain to the frequency domain, equivalent to traditional Doppler broadening temperature measurement, utilizes an etalon or overheating cavity method to generate an optical sweep frequency, then extracts the Doppler broadening height of the frequency domain absorption spectrum, and finally substitutes it into the temperature measurement formula to obtain the thermodynamic temperature.

[0009] Furthermore, the light source module includes a narrow-linewidth laser, an optical isolator, a half-wave plate, and a polarizing beam splitter. The narrow-linewidth laser outputs a narrow-linewidth frequency-modulated continuous wave, covering the absorption lines of atoms or molecules. The optical isolator prevents reflected light from affecting the light source. The half-wave plate and polarizing beam splitter are used in combination to adjust the ratio of reflected to transmitted light. After passing through the optical isolator and the half-wave plate, the output light from the narrow-linewidth laser enters the polarizing beam splitter and is split into two paths. One path enters the linear frequency sweep control module, while the other path enters the temperature measurement module to generate an absorption spectrum.

[0010] Furthermore, the linear frequency sweep control module includes a scanning source, an optical fiber coupler, a fiber optic Mach-Zehnder interferometer, a photodetector, a multiplier, a reference frequency source, a frequency and phase detector, a low-pass filter, and an adder. The scanning source outputs a sawtooth wave, which is then loaded onto a narrow-linewidth laser to achieve the optical frequency sweep function. The optical fiber coupler collects the reflected light from the polarization beam splitter. The combination of the fiber optic Mach-Zehnder interferometer and the photodetector provides a nonlinear correction signal in real time during the optical frequency sweep. The multiplier performs a mixing function between the nonlinear correction signal and the reference frequency source. The frequency and phase detector receives the mixed signal and generates a feedback control electrical signal. The low-pass filter filters out high-frequency signal interference from the feedback control electrical signal. The adder superimposes the sawtooth wave signal with the electrical signal output from the low-pass filter. The reflected light from the polarization beam splitter enters the Mach-Zehnder interferometer through the optical fiber coupler, and the two arms beat in the photodetector to form a nonlinear correction signal. The nonlinear correction signal is mixed with the reference frequency source output signal by a multiplier. The mixed electrical signal enters a frequency and phase discriminator to generate a feedback control signal, which is then superimposed with a sawtooth wave signal after passing through a low-pass filter and an adder, and input to the narrow-linewidth laser control port. The linear sweep frequency control module uses a scanning source, a fiber Mach-Zehnder interferometer, and a feedback control circuit to achieve linear frequency sweep of the light output from the light source module. The scanning source outputs a sawtooth wave, causing the light output from the light source module to cover the absorption lines of atoms or molecules. The light output from the light source module enters the fiber Mach-Zehnder interferometer and is split into two paths: one is a fiber jumper, and the other is a delay fiber. The two paths are combined and beat in the detector to generate a nonlinear correction signal. The feedback control circuit stabilizes the nonlinear correction signal, thereby ensuring linear output of the optical frequency during the sweep frequency process.

[0011] Furthermore, the temperature measurement module includes a half-wave plate, an acousto-optic modulator, a temperature control module, a MEMS chamber, a first lens, a first detector, a second lens, and a second detector. The half-wave plate is used to adjust the polarization direction of the transmitted light from the polarizing beam splitter; the acousto-optic modulator generates two diffracted beams, one of the 0th order and one of the +1st order; the temperature control module provides high-precision temperature control and magnetic shielding for the MEMS chamber; the MEMS chamber is a temperature sensor; the first lens and the first detector combine to collect the 0th order diffracted light; the second lens and the second detector combine to collect the +1st order diffracted light. The transmitted light from the polarizing beam splitter, after passing through the half-wave plate and the acousto-optic modulator, generates 0th and +1st order diffracted light. These two beams interact with the MEMS chamber inside the temperature control module, and then the two beams carrying temperature information are collected by their respective detectors through the corresponding lenses. The temperature measurement module uses an acousto-optic modulator to generate two absorption spectrum signals with known frequency differences that are related to temperature. The time difference of the same peak on the two absorption spectrum lines corresponds to the driving frequency of the acousto-optic modulator, that is, ΔT = T1 - T2 corresponds to the driving frequency f of the acousto-optic modulator, thereby realizing the frequency calibration of the absorption spectrum.

[0012] Furthermore, the signal acquisition and temperature calculation module includes a signal acquisition module and a temperature calculation module. The signal acquisition module acquires sawtooth wave and absorption spectrum signals output by two detectors at a preset sampling rate; the temperature calculation module calculates the temperature of the gas chamber based on the two acquired absorption spectrum lines to obtain the temperature of the gas chamber.

[0013] A rapid temperature measurement method based on micro-cell dual absorption spectrum is disclosed, implemented using a rapid temperature measurement device based on micro-cell dual absorption spectrum. The temperature calculation module calculates the temperature of the cell based on the two acquired absorption spectra. The implementation method includes the following steps:

[0014] Step 1: Plotting Test Data. Plot the three electrical signals input to the signal acquisition module onto the same coordinate system using a preset sampling rate. The three signals are a sawtooth wave signal, a 0th-order diffraction absorption spectrum, and a +1st-order diffraction absorption spectrum, respectively. The horizontal axis represents time, and the vertical axis represents voltage value.

[0015] Step 2: Single-cycle processing. Based on the sawtooth wave starting point, the multi-cycle data is divided into multiple groups of single-cycle data, each group containing complete 0th and +1st order diffraction absorption spectrum curves.

[0016] Step 3: Time-domain to frequency-domain mapping. In the same coordinate system, select a set of single-cycle data and obtain the time difference of the same absorption peak from the 0th and +1st order diffraction absorption spectrum curves. This time difference corresponds to the acousto-optic modulator driving frequency, i.e., ΔT = T1 - T2 corresponds to the acousto-optic modulator driving frequency f. Through the correspondence between the time difference and the driving frequency, the absorption spectrum is transformed from the time domain to the frequency domain. T1 and T2 are the times when the same peak appears on the 0th and +1st order diffraction lines, respectively.

[0017] Step 4: Temperature Calculation. Calculate the temperature using the 0th-order absorption spectrum converted to the frequency domain. Fit the curve to obtain the Doppler full width at half maximum (FWHM) of the absorption peak, and then calculate the temperature using the following formula.

[0018]

[0019] In the formula: M is the atomic or molecular mass; v0 is the center frequency of the spectral line, Δv D λ represents the Doppler full width at half maximum (FWHM) of the absorption peak; T represents the thermodynamic temperature.

[0020] Beneficial effects:

[0021] 1. Traditional Doppler broadening temperature measurement requires the use of etalons such as wavelength meters and ultra-stable cavities. These etalons are large and expensive, making miniaturization, practical application, and integration difficult. This invention discloses a rapid optical temperature measurement method and device based on micro-cell dual absorption spectra. It utilizes a fiber optic Mach-Zehnder interferometer, an acousto-optic modulator, and a MEMS micro-cell to achieve temperature measurement, significantly reducing system size and lowering device cost.

[0022] 2. Traditional Doppler broadening temperature measurement methods utilize wavelength meters, ultra-stable cavities, and other etalons to achieve frequency stabilization and sweeping, resulting in slow measurement speeds. This invention discloses a rapid optical temperature measurement method and device based on a micro-cell dual absorption spectrum. It utilizes a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to achieve optical linear frequency sweeping, with the rapid sweeping process corresponding to the temperature measurement process. This method eliminates the need for sequential measurements at equally spaced points, as is required in traditional sweeping methods, and omits the single-point frequency stabilization process, significantly improving measurement speed from tens of minutes to seconds.

[0023] 3. The nonlinearity between the laser output wavelength and the injected current introduces errors when using only sawtooth wave-controlled laser frequency sweeping for temperature measurement. This invention discloses a rapid optical temperature measurement method and device based on a micro-cell dual absorption spectrum. Building upon optical linear frequency sweeping achieved using a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit, it utilizes an acousto-optic modulator to generate two absorption spectral lines and calibrates the spectral frequency based on the time difference between the appearance of the same absorption peak and the corresponding driving frequency. This invention effectively solves the nonlinear error problem associated with single sawtooth wave-controlled lasers, resulting in high measurement accuracy.

[0024] 4. Traditional Doppler broadening temperature measurement devices are complex and easily affected by external environmental factors, such as vibration. This invention discloses a rapid optical temperature measurement method and device based on micro-cell dual absorption spectrum. Building upon the aforementioned beneficial effects 1, 2, and 3, it achieves easier integration through the integration of optical paths and integrated circuits. The integrated testing system possesses advantages such as high integration degree, simple structure, and good environmental adaptability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a rapid temperature measurement device based on a micro-cell dual absorption spectrum according to the present invention.

[0026] Among them: 1—Light source module, 2—Linear sweep frequency control module, 3—Temperature measurement module, 4—Signal acquisition and temperature calculation module;

[0027] 101—Narrow linewidth laser, 102—Optical isolator, 103—Half-wave plate, 104—Polarizing beam splitter;

[0028] 201—Scanning source, 202—Fiber optic coupler, 203—Fiber optic Mach-Zehnder interferometer, 204—Photodetector, 205—Multiplier, 206—Reference frequency source, 207—Frequency and phase detector, 208—Low-pass filter, 209—Adder;

[0029] 301—Half-wave plate, 302—Acousto-optic modulator, 303—Gas chamber temperature control module, 304—MEMS gas chamber, 305—First lens, 306—First detector, 307—Second lens, 308—Second detector;

[0030] 401—Acquisition Module, 402—Temperature Calculation Module. Detailed Implementation

[0031] To better illustrate the purpose and advantages of the present invention, the invention will be further described below in conjunction with the accompanying drawings and examples.

[0032] Example 1:

[0033] like Figure 1 As shown in the figure, this embodiment discloses a rapid temperature measurement device based on a micro-cell dual absorption spectrum, including a light source module 1, a linear sweep frequency control module 2, a temperature measurement module 3, and a signal acquisition and temperature calculation module 4. The light source module 1 provides a cesium atom D1 line sweep frequency laser; the linear sweep frequency control module 2 is used to implement the laser linear sweep frequency function; the temperature measurement module is used to acquire two absorption spectra with known frequency differences (i.e., a frequency difference of 350MHz at the same time) carrying temperature information; the signal acquisition and temperature calculation module 4 is used for signal acquisition, processing, and calculation of the temperature of the gas cell.

[0034] MEMS microcells are fabricated using semiconductor processing techniques and filled with elemental cesium (Cs). The laser is a distributed Bragg reflector (DBR) laser, but not limited to this type, and the laser output frequency can cover the D1 line of cesium atoms. The acousto-optic modulator is driven at a frequency of 350 MHz. The fiber optic delay arm of the Mach-Zehnder interferometer is 5 km long.

[0035] The light source module 1 includes a narrow-linewidth laser 101, an optical isolator 102, a half-wave plate 103, and a polarizing beam splitter 104. The output light from the narrow-linewidth laser 101 is split into two paths after passing sequentially through the optical isolator 102, the half-wave plate 103, and the polarizing beam splitter 104. The optical isolator 102 is used to prevent reflected light from affecting the laser. The half-wave plate 103 and the polarizing beam splitter 104 are used to adjust the splitting ratio of the two beams. One beam enters the linear frequency sweep control module 2, while the other beam enters the temperature measurement module 3 to generate an absorption spectrum.

[0036] The linear sweep frequency control module 2 includes a scanning source 201, an optical fiber coupler 202, an optical fiber Mach-Zehnder interferometer 203, a photodetector 204, a multiplier 205, a reference frequency source 206, a frequency and phase discriminator 207, a low-pass filter 208, and an adder 209. The scanning source 201 outputs a sawtooth wave electrical signal to achieve a sweep frequency output of the narrow linewidth laser 101, with a frequency of 5Hz and an amplitude of 400mV. The reflected light from the polarization beam splitter 104 passes through the optical fiber coupler 202 and enters the optical fiber Mach-Zehnder interferometer 203. After the two arms of the optical signal are combined, they enter the photodetector 204 and beat to obtain a nonlinear correction signal. The nonlinear correction signal enters multiplier 205 and is mixed with reference frequency source 206. The mixed electrical signal enters frequency and phase detector 207 to obtain feedback control electrical signal. The feedback control electrical signal then passes through low-pass filter 208 and adder 209, and is superimposed with sawtooth wave signal before entering the control signal input terminal of narrow linewidth laser 101. Fiber coupler 202 couples the reflected light from polarization beam splitter 104 into the fiber. The fiber optic Mach-Zehnder interferometer 203 and photodetector 204 are combined to obtain the nonlinear correction beat frequency signal. Multiplier 205 mixes the output signal of reference frequency source 206 with the beat frequency signal. Frequency and phase detector 207 receives the mixed signal and outputs the feedback control signal. Low-pass filter 208 filters out high-frequency signals in the feedback control signal; adder 209 superimposes the feedback control signal and sawtooth wave signal. The linear sweep frequency control module 2 utilizes a scanning source 201, a fiber optic Mach-Zehnder interferometer 203, and a series of circuit components to achieve linear sweep frequency of the light output from the light source module 1. The scanning source 201 outputs a sawtooth wave, causing the light output from the light source module 1 to cover the D1 line of cesium atoms. After the light output from the light source module 1 enters the fiber optic Mach-Zehnder interferometer 203, it is split into two paths: one is a fiber optic jumper, and the other is a delay fiber. The two paths are combined and beat in the detector to generate a nonlinear correction signal. Then, a feedback control circuit composed of a series of electrical components stabilizes the beat signal, thereby ensuring linear output of the optical frequency during the sweep frequency process.

[0037] The temperature measurement module 3 includes a half-wave plate 301, an acousto-optic modulator 302, a temperature control module 303, a MEMS gas chamber 304, a first lens 305, a first detector 306, a second lens 307, and a second detector 308. The transmitted light from the polarizing beam splitter 104 passes through the half-wave plate 301 and the acousto-optic modulator 302, generating 0th and +1st order diffracted beams. The acousto-optic modulator has a driving frequency of 350MHz. These two diffracted beams enter the MEMS gas chamber 304 inside the temperature control module 303 and interact with cesium atoms to generate two absorption spectra carrying temperature information. Subsequently, the 0th order diffracted beam is collected by the first detector 306 through the first lens 305, and the +1st order diffracted beam is collected by the second detector 308 through the second lens 307. The half-wave plate 301 is used to control the laser polarization direction; the acousto-optic modulator is used to generate two diffracted beams with a defined frequency difference; and the temperature control module 303 is used to maintain a constant temperature in the MEMS gas chamber 304 and to shield the magnetic field. The temperature measurement module 3 uses the acousto-optic modulator 302 to generate two absorption spectrum signals with known frequency differences and related to temperature. The time difference of the same peak on the two absorption spectrum lines corresponds to the driving frequency of the acousto-optic modulator, that is, ΔT=T1-T2 corresponds to the driving frequency f of the acousto-optic modulator, so as to realize the frequency calibration of the absorption spectrum.

[0038] The signal acquisition and temperature calculation module 4 includes a signal acquisition module 401 and a temperature calculation module 402. The sawtooth wave signal and the two absorption spectrum signals collected by the first detector 306 and the second detector 308 are acquired by the acquisition module 401 at a fixed sampling rate of 10kHz. The acquired signals are then transmitted to the temperature calculation module 402 for processing and calculation, and finally the temperature of the air chamber is calculated.

[0039] This embodiment discloses a rapid temperature measurement method based on micro-cell dual absorption spectrum, based on the aforementioned... Figure 1 The temperature measuring device is implemented. The temperature calculation module 402 calculates the temperature of the gas chamber based on the two collected absorption spectra. The specific implementation steps are as follows:

[0040] Step 1: Plotting Test Data. First, in the temperature calculation module, plot the three signals acquired by the signal acquisition module at a preset sampling rate—namely, the sawtooth wave electrical signal output from the scanning source, the 0th-order diffraction absorption spectrum signal, and the +1st-order diffraction absorption spectrum signal—onto the same coordinate system. The horizontal axis represents time, and the vertical axis represents voltage amplitude. The signal acquisition module's sampling rate is 10kHz, and the interval between adjacent points is 0.1ms.

[0041] Step 2: Single-cycle processing. Based on the starting point of the sawtooth wave, the multi-cycle data drawn in Step 1 is divided into single-cycle data. The single-cycle data contains the 0th and +1st order diffraction absorption spectrum signals of a complete cycle for subsequent processing.

[0042] Step 3: Time-domain to frequency-domain mapping. The time difference between the appearance of the same absorption peak of the cesium atom D1 line in the 0th and +1st order diffraction absorption spectra corresponds to the driving frequency applied to the acousto-optic modulator 302, which is 350MHz. The optical frequency change corresponding to 0.1ms is calculated. Then, the horizontal axis is converted from time to frequency to obtain the absorption spectrum in the frequency domain.

[0043] Step 4: Temperature Calculation. The temperature is calculated using the 0th-order absorption spectrum converted to the frequency domain. The 0th-order spectrum is fitted to obtain the Doppler full width at half maximum (FWHM) of the D1 line absorption peak. The thermodynamic temperature is then calculated using the following formula.

[0044]

[0045] In the formula: M is the atomic or molecular mass; v0 is the center frequency of the spectral line, Δv D λ represents the Doppler full width at half maximum (FWHM) of the absorption spectral line; T represents the thermodynamic temperature.

[0046] Each of the above steps is implemented in a MATLAB program, and each step corresponds to a MATLAB programming algorithm.

[0047] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rapid temperature measurement device based on micro-cell dual absorption spectrum, characterized in that: The system includes a light source module (1), a linear sweep frequency control module (2), a temperature measurement module (3), and a signal acquisition and temperature calculation module (4). The light source module (1) is used to provide narrow-linewidth tunable sweep frequency laser. The linear sweep frequency control module (2) realizes optical linear sweep frequency based on a scanning source, a fiber Mach-Zehnder interferometer, and a feedback control circuit. The temperature measurement module (3) generates two micro-cell absorption spectrum signals carrying temperature information through an acousto-optic modulator. The signal acquisition and temperature calculation module (4) is used to acquire the two absorption spectra and calculate the temperature of the cell based on the two absorption spectra. The output light of the light source module (1) is split into two beams, which simultaneously enter the linear sweep frequency control module (2) and the temperature measurement module (3) respectively. The linear sweep frequency control module (2) uses a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to control the output light of the light source module (1) to achieve linear sweep frequency. The scanning source outputs a sawtooth wave, so that the output light of the light source module (1) covers the absorption lines of atoms or molecules. After the output light of the light source module (1) enters the fiber optic Mach-Zehnder interferometer, it is split into two paths, one is a fiber optic jumper, and the other is a delay fiber. After the two paths are combined, they beat in the detector to generate a sweep frequency nonlinear correction signal. The nonlinear correction signal is stabilized through the feedback control circuit to ensure linear output of the optical frequency during the sweep frequency process. The injection current and the output optical frequency have a nonlinear relationship during the sawtooth wave sweep frequency. The linearity of the frequency sweep process is improved by using a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit. The temperature measurement module (3) uses an acousto-optic modulator to generate two absorption spectrum signals with known frequency differences that are related to temperature. The time difference between the same absorption peak in the two absorption spectra corresponds to the driving frequency f of the acousto-optic modulator. Combining the linear frequency sweep control module (2) and the temperature measurement module (3), on the basis of ensuring that the output light of the light source module (1) achieves linear frequency sweep, based on the principle that the time difference between the same peak in the two absorption spectra corresponds to the driving frequency, that is, ΔT=T1-T2 corresponds to the driving frequency f of the acousto-optic modulator, the frequency calibration of the absorption spectrum signal is realized, and then the absorption spectrum is mapped from the time domain to the frequency domain. The Doppler half-width of the frequency domain absorption spectrum is extracted and then substituted into the temperature measurement formula to obtain the thermodynamic temperature. The temperature measurement module (3) includes a half-wave plate (301), an acousto-optic modulator (302), a temperature control module (303), a MEMS chamber (304), a first lens (305), a first detector (306), a second lens (307), and a second detector (308); the half-wave plate (301) is used to adjust the polarization direction of the transmitted light from the polarization beam splitter (104); the acousto-optic modulator (302) generates two diffracted beams, one of the 0th order and one of the +1st order; the temperature control module (303) provides temperature control and magnetic shielding functions for the MEMS micro-chamber (304); the MEMS... The S-microcell (304) is a temperature sensor; the first lens (305) and the first detector (306) are combined to collect the 0th order diffracted light; the second lens (307) and the second detector (308) are combined to collect the +1st order diffracted light; the light transmitted by the polarizing beam splitter (104) passes through the half-wave plate (301) and the acousto-optic modulator (302) to generate 0th and +1st order diffracted light. These two beams of light interact with the MEMS cell (304) inside the temperature control module (303), and then the two beams of light carrying temperature information are collected by the corresponding detectors through the corresponding lenses.

2. The rapid temperature measurement device based on micro-cell dual absorption spectrum according to claim 1, characterized in that: The light source module (1) includes a narrow linewidth laser (101), an optical isolator (102), a half-wave plate (103), and a polarizing beam splitter (104). The narrow linewidth laser (101) outputs a narrow linewidth frequency-modulated continuous wave that covers the absorption spectrum of atoms or molecules. The optical isolator (102) prevents reflected light from affecting the light source. The half-wave plate (103) and the polarizing beam splitter (104) are used in combination to adjust the ratio of reflected light to transmitted light. After the light output from the narrow linewidth laser (101) passes through the optical isolator (102) and the half-wave plate (103), it enters the polarizing beam splitter (104) and is split into two paths. One path enters the linear sweep frequency control module (2), while the other path enters the temperature measurement module (3) to generate an absorption spectrum.

3. The rapid temperature measurement device based on micro-cell dual absorption spectrum according to claim 1, characterized in that: The linear frequency sweep control module (2) includes a scanning source (201), an optical fiber coupler (202), an optical fiber Mach-Zehnder interferometer (203), a photodetector (204), a multiplier (205), a reference frequency source (206), a frequency and phase detector (207), a low-pass filter (208), and an adder (209). The scanning source (201) outputs a sawtooth wave, which is then loaded onto a narrow-linewidth laser (101) to achieve the optical frequency sweep function. The optical fiber coupler (202) is used to collect the reflected light from the polarization beam splitter (104). A Hertzsprung-Zehnder interferometer (203) and a photodetector (204) are combined to provide a nonlinear correction signal in real time during optical frequency sweeping; the multiplier (205) performs a mixing function between the nonlinear correction signal and the reference frequency source (206); the frequency and phase detector (207) receives the mixing signal and generates a feedback control electrical signal; the low-pass filter (208) filters out the influence of high-frequency signals in the feedback control electrical signal; the adder (209) superimposes the sawtooth wave signal with the electrical signal output from the low-pass filter (208); polarization beam splitting... The light reflected by the prism (104) enters the Mach-Zehnder interferometer (203) through the fiber coupler (202). The optical signals from both arms beat in the photodetector (204) to form a nonlinear correction signal. The nonlinear correction signal enters the multiplier (205) and is mixed with the output signal of the reference frequency source (206). The mixed electrical signal enters the frequency and phase detector (207) to generate a feedback control signal. After passing through the low-pass filter (208) and the adder (209), it is superimposed with the sawtooth wave signal and input to the control port of the narrow linewidth laser (101). The frequency sweep control module (2) uses a scanning source, a fiber optic Mach-Zehnder interferometer, and a feedback control circuit to realize the linear frequency sweep of the light output from the light source module (1); the scanning source outputs a sawtooth wave, so that the light output from the light source module (1) covers the absorption lines of atoms or molecules; after the light output from the light source module (1) enters the fiber optic Mach-Zehnder interferometer, it is divided into two paths, one is a fiber optic jumper, and the other is a delay fiber. After the two paths are combined, a beat frequency nonlinear correction signal is generated in the detector. The beat frequency nonlinear correction signal is stabilized through the feedback control circuit, thereby ensuring the linear output of the optical frequency during the frequency sweep process.

4. The rapid temperature measurement device based on micro-cell dual absorption spectrum according to claim 1, characterized in that: The signal acquisition and temperature calculation module (4) includes a signal acquisition module (401) and a temperature calculation module (402); the signal acquisition module (401) acquires sawtooth waves and absorption spectrum signals output by two detectors at a preset sampling rate; the temperature calculation module (402) calculates the temperature of the gas chamber based on the two absorption spectrum lines acquired, and obtains the temperature of the gas chamber.

5. A rapid temperature measurement method based on micro-cell dual absorption spectrum, implemented based on the rapid temperature measurement device based on micro-cell dual absorption spectrum as described in claim 4, characterized in that: The temperature calculation module (402) calculates the temperature of the gas chamber based on the two collected absorption spectra, and the method includes the following steps: Step 1: Plotting test data; Plot the three electrical signals input to the signal acquisition module (401) onto the same coordinate system at a preset sampling rate. The three signals are sawtooth wave signal, 0th order diffraction absorption spectrum and +1st order diffraction absorption spectrum, respectively. The horizontal axis is time and the vertical axis is voltage value. Step 2: Single-cycle processing; Based on the sawtooth wave initiation point, the multi-period data is divided into multiple groups of single-period data, each group containing complete 0th and +1st order diffraction absorption spectrum curves. Step 3: Time-domain to frequency-domain mapping; Under the same coordinate system, select a set of single-cycle data, and obtain the time difference of the same absorption peak from the 0th and +1st order diffraction absorption spectrum curves. This time difference corresponds to the driving frequency of the acousto-optic modulator (302), that is, ΔT = T1 - T2 corresponds to the driving frequency f of the acousto-optic modulator. Through the correspondence between the time difference and the driving frequency, the absorption spectrum is converted from the time domain to the frequency domain; T1 and T2 are the times when the same peak appears on the 0th and +1st order diffraction lines, respectively. Step 4: Temperature Calculation; Calculate the temperature using the 0th-order absorption spectrum converted to the frequency domain. Fit the curve to obtain the Doppler full width at half maximum (FWHM) of the absorption peak, and then calculate the temperature using the following temperature formula. In the formula: M is the atomic or molecular mass; v0 is the center frequency of the spectral line, Δv D λ represents the Doppler full width at half maximum (FWHM) of the absorption peak; T represents the thermodynamic temperature.

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