Fourier spectrometer half-wave resampling adaptive time calibration device and method

Abstract

The invention discloses a Fourier spectrometer half-wave resampling adaptive time calibration device, which comprises a laser output module, a long optical path gas absorption cell module, a fast scanning Fourier spectrometer optical system and a displacement table control and data acquisition parallel processing module, the invention further discloses a Fourier spectrometer half-wave resampling self-adaptive time calibration method, parallel processing of signal scanning, data acquisition, data storage and cache emptying is realized through the displacement table control and data acquisition parallel processing module, and second-order translational continuous scanning is realized. The problem that the optical path difference of sampling points changes unevenly under long-range scanning of a linear electric displacement table is solved, and the signal-to-noise ratio and the resolution ratio of a laser spectrum and an absorption spectrum can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrafast molecular spectroscopy, and in particular relates to a device and method for half-wave resampling adaptive time calibration of a Fourier spectrometer. Background Art

[0002] Fourier spectroscopy is a dual-beam interference spectroscopy technique that utilizes the principle of a Michelson interferometer to generate interference light. This interference light then interacts with the sample, embedding the sample's absorption spectrum information into the interference light. The scanning time depends on the interference spectrum, and Fourier transform demodulation yields the sample's absorption spectrum. This technique can detect and identify the unique vibrational and rotational energy level structure of molecules and is commonly used to detect sample components and their corresponding concentrations. It possesses high sensitivity, high resolution, and high precision, and has broad applications in numerous fields, including human health, environmental protection, industrial production, and atmospheric exploration. With the continuous development of Fourier spectroscopy, its spectral range is expanding, and its measurement accuracy is also improving.

[0003] One of the keys to obtaining high-precision, high-resolution broadband Fourier ultrafast spectroscopy is collecting interferometric signal data with a sufficient number of sample points and a sufficiently large scanning range. To collect more sample points, a continuous scanning method has been developed. This involves performing a single scan of the scanning range at a specified speed. The displacement platform accelerates from the scan start point to a specified speed, then transitions to uniform motion. As the platform approaches the scan end point, it decelerates to a stationary state. During this process, the complete interferometric data from the scan is collected and stored. However, due to voltage fluctuations in the pump source and the temperature changes in the gain medium caused by long-term operation, the laser beam drifts over extended periods of operation. Furthermore, the displacement platform undergoes non-uniform acceleration and deceleration during startup and shutdown, and the uniform motion in the intermediate stages also exhibits drift in travel speed. These factors all lead to a non-uniform distribution of the collected interferometric signal sample points across the optical delay, reducing the quality of the interferometric signal and further affecting spectral accuracy and resolution. Summary of the Invention

[0004] The object of the present invention is to address the above-mentioned problems existing in the prior art and to provide a device and method for adaptive time calibration of a Fourier spectrometer using half-wave resampling.

[0005] The above-mentioned purpose of the present invention is achieved by the following technical means: A device for half-wave resampling adaptive time calibration of a Fourier spectrometer includes signal light and reference light. The signal light sequentially passes through a gas absorption cell and is combined with the reference light to form a combined light beam. The combined light beam is split by a first thin film beam splitter to form a first transmitted light and a first reflected light. The first transmitted light and the first reflected light are both incident on a hollow roof prism retroreflective mirror assembly. The first transmitted light emitted by the hollow roof prism retroreflective mirror assembly is further split by a second thin film beam splitter into a second transmitted light A and a second reflected light A. The first reflected light emitted by the hollow roof prism retroreflective mirror assembly is further split by the second thin film beam splitter into a second transmitted light B and a second reflected light B. The second transmitted light A and the second reflected light B are combined, and the signal light component in the second transmitted light A and the signal light component in the second reflected light B interfere to form a first interference signal light. The reference light component in the second transmitted light A and the reference light component in the second reflected light B interfere to form a first interference reference light. The first interference reference light is filtered out by the long-pass filter, and the first interference signal light passes through the long-pass filter and is detected by the first InAsSb photodetector. The second transmitted light B and the second reflected light A are combined, and the signal light component in the second transmitted light B interferes with the signal light component of the second reflected light A to form a second interference signal light. The reference light component in the second transmitted light B interferes with the reference light component of the second reflected light A to form a second interference reference light. After the second interference signal light and the second interference reference light are combined, they are incident on a short-pass filter. The second interference signal light is reflected by the short-pass filter to a second InAsSb photodetector for detection. The second interference reference light passes through the short-pass filter and is incident on a silicon avalanche photodetector.

[0006] As described above, the signal light passes through the aperture and enters the gas absorption cell. The signal light exiting the gas absorption cell passes through the beam reduction lens group and is combined with the reference light passing through the aperture.

[0007] As described above, the focusing lens group includes a convex lens and a concave lens.

[0008] As described above, the hollow roof prism retroreflector group includes a base, and a first hollow roof prism reflector group and a second hollow roof prism reflector group are arranged on both sides of the base, and a first reflector group and a second reflector group are arranged on the sides of both sides of the base. The respective hollow roof prism reflectors of the first hollow roof prism reflector group cooperate with the respective reflectors of the first reflector group, so that the incident first transmitted light repeatedly travels back and forth laterally and propagates forward; the respective hollow roof prism reflectors of the second hollow roof prism reflector group cooperate with the respective reflectors of the second reflector group, so that the incident first reflected light repeatedly travels back and forth laterally and propagates forward.

[0009] As described above, the base is driven by the linear electric translation stage to move linearly, thereby changing the distance between the first hollow roof prism reflector group and the first reflector group, and at the same time changing the distance between the second hollow roof prism reflector group and the second reflector group.

[0010] The utility model also includes a linear reciprocating motion control module of the linear electric translation stage for controlling the motion of the linear electric translation stage.

[0011] It also includes a first data acquisition card for collecting signals from the first InAsSb photodetector and the second InAsSb photodetector, and a second data acquisition card for collecting signals from the silicon avalanche photodetector.

[0012] It also includes a synchronous clock continuous acquisition module for synchronizing the clocks of the first data acquisition card and the second data acquisition card.

[0013] It also includes a dual-channel signal self-balancing processing and analysis module, which is used to normalize the signals collected by the first InAsSb photodetector and the second InAsSb photodetector and then perform difference processing to obtain a self-balancing signal, calculate the average value of the second interference reference light signal collected by the silicon avalanche photodetector, subtract the above average value from the second interference reference light signal to obtain a new interference spectrum, extract the time corresponding to the zero point of the new interference spectrum, extract the self-balancing signal at the corresponding time to obtain half-wave resampled interference signal light data, perform Fourier transform on the half-wave resampled interference signal light data, and obtain the final laser spectrum signal.

[0014] The method for adaptive time calibration of a Fourier spectrometer half-wave resampling comprises the following steps: Step 1: The first data acquisition card and the second data acquisition card perform clock synchronization; Step 2: The linear electric translation stage starts and accelerates to the set movement speed and maintains a uniform scanning speed. The first data acquisition card collects the signal of the first interference signal light through the first InAsSb photodetector and stores it in the internal RAM of the first data acquisition card. The first data acquisition card collects the signal of the second interference signal light through the second InAsSb photodetector and stores it in the internal RAM of the first data acquisition card. The second data acquisition card collects the signal of the second interference reference light through the silicon avalanche photodetector and stores it in the internal RAM of the second data acquisition card. When the RAM storage space is exhausted, the data in the RAM is transferred to the computer hard disk and the RAM storage space is cleared. The above collection, storage, transfer, and clearing steps are repeated in a cycle until the linear electric translation stage starts to decelerate and stop. During the entire scanning and signal acquisition process, the linear electric translation stage maintains a uniform motion. Step 3. The signals collected by the first InAsSb photodetector and the second InAsSb photodetector are normalized and then differenced to obtain a self-balanced signal. The second interference reference light signal collected by the silicon avalanche photodetector is averaged, and the above average value is subtracted from the second interference reference light signal to obtain a new interference spectrum oscillating up and down around the zero point. The time corresponding to the zero point of the new interference spectrum is extracted, and the self-balanced signal at the corresponding time is extracted to obtain half-wave resampled interference signal light data. The half-wave resampled interference signal light data is Fourier transformed to obtain the final laser spectrum signal.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention realizes parallel processing of scanning signals, collecting data, storing data, and clearing cache through the translation stage control and data acquisition parallel processing module, realizing second-level translational continuous scanning. The first interference signal light and the second interference signal light are normalized and then subjected to difference processing to obtain a self-balancing signal. A new interference spectrum is obtained based on the second interference reference light signal, and the time corresponding to the zero point of the new interference spectrum is extracted. The self-balancing signal at the corresponding time is extracted to obtain half-wave resampled interference signal light data, which greatly reduces the influence of unstable operation of the laser on the extraction of the interference signal and improves the interference spectrum sample acquisition quality and spectral resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the optical path of the present invention; Among them, 100: laser output module; 101: mid-infrared femtosecond laser frequency comb light source; 102: He-Ne continuous laser; 103: aperture; 200: long optical path gas absorption cell module; 201: gas absorption cell; 202: beam reduction lens group; 203: high-transmittance and low-reflection dichroic mirror; 300: fast scanning Fourier spectrometer optical system; 301: first thin film beam splitter; 302: hollow roof prism retroreflective mirror group; 303: linear electric translation stage; 304: second thin film beam splitter; 305: long-pass filter; 306: short-pass filter; 307: balanced detector; 308: silicon avalanche photodetector. DETAILED DESCRIPTION

[0017] In order to facilitate those skilled in the art to understand and implement the present invention, the present invention is further described in detail below with reference to the embodiments. The embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0018] Example 1: The device for adaptive time calibration of a half-wave resampling Fourier spectrometer comprises: a laser output module 100, a long optical path gas absorption cell module 200 (this embodiment uses a Herriott long optical path gas absorption cell module), a fast scanning Fourier spectrometer optical system 300, and a translation stage control and data acquisition parallel processing module. Figure 1 .

[0019] The laser output module 100 includes a mid-infrared femtosecond laser frequency comb light source 101 for generating a light source that interacts with the sample gas, a HeNe continuous laser 102 used as a medium-interval phase reference for laser phase correction, and an aperture 103; The mid-infrared femtosecond laser frequency comb source 101 has an output laser wavelength range of 3.2-3.7 μm, a pulse width of 150 fs, and a repetition rate of 200 MHz. The 3.2-3.5 μm mid-infrared band covered encompasses the absorption spectra of key molecules related to environmental pollution and human health, such as methane, hydrogen sulfide, acetylene, and OCS. This source interacts with the sample gas, embedding the sample's vibrational and rotational energy level absorption spectrum into the laser spectrum, and is therefore also referred to as signal light.

[0020] The output laser wavelength of the HeNe continuous laser 102 is continuous light at 632.8 nm. The 632.8 nm HeNe continuous laser 102 outputs visible light, which is sufficiently far from the mid-infrared band. Therefore, the combined beam of signal light and reference light can be separated by coatings of different materials, and is used to provide equally spaced phase references for light field phase correction in laser propagation. Therefore, it can also be called reference light.

[0021] The aperture 103 is used to calibrate the direction of the lasers output by the mid-infrared femtosecond laser frequency comb light source 101 and the HeNe continuous laser 102 , and to filter out unnecessary stray light.

[0022] The long optical path gas absorption cell module 200 provides a vacuum-sealed environment for the interaction between the laser and the sample gas, and is the source of the molecular absorption spectrum signal detected by the Fourier spectrometer. The long optical path gas absorption cell module 200 includes: a gas absorption cell 201, a beam reduction lens group 202 and a high-transmittance, low-reflection dichroic mirror 203.

[0023] The gas absorption cell 201 (a Herriott gas absorption cell is used in this embodiment) is the place where the signal light interacts with the sample gas. The signal light interacts with the sample gas in the absorption cell of the gas absorption cell 201. The sample gas absorbs photons of a specific frequency, causing the ground state electrons to transition to the corresponding vibrational rotational energy level, thereby leaving obvious absorption lines in the signal light spectrum, and obtaining the absorption spectrum of the sample molecule.

[0024] The gas absorption cell 201 includes an absorption cell, and the two light holes on the absorption cell are respectively sealed with an incident window and an exit window. The incident window and the exit window are made of ZnSe material, so that a sealed environment is formed inside the absorption cell. The interior of the absorption cell is embedded with multiple gold film reflectors with fixed positions and fixed reflection angles. After passing through the aperture 103, the signal light enters the absorption cell from the incident window, and is reflected by each gold film reflector. After propagating a distance of 500 cm in the absorption cell, it passes through the exit window and leaves the absorption cell. During the long-distance propagation in the absorption cell, the signal light interacts with the sample gas in the absorption cell and absorbs photons of frequencies corresponding to the molecular vibrational energy levels, which is the source of the molecular absorption spectrum signal detected by the Fourier spectrometer.

[0025] The focusing lens assembly 202 comprises a convex lens and a concave lens, forming a telescope system that focuses the signal light emitted from the absorption cell, reducing the spot size from 13 mm to 3 mm. Because the signal light travels five meters within the gas absorption cell, the spot size inevitably diverges. To preserve the complete absorption spectrum while converging the beam, the focusing lens assembly 202, rather than an aperture, is used to control the spot size.

[0026] The high-transmittance, low-reflection dichroic mirror 203 is coated with a laser-responsive material with high long-wavelength transmittance and high short-wavelength reflectivity. With 950nm as the boundary, the signal light with a longer wavelength has a high transmittance of 95%, and the reference light with a shorter wavelength has a high reflectivity of 95%. It is used to achieve the combination of signal light and reference light. The signal light after being beam-reduced by the beam-reduction lens group 202 is transmitted through the high-transmittance, low-reflection dichroic mirror 203, and the reference light emitted by the aperture 103 is reflected by the high-transmittance, low-reflection dichroic mirror 203. The signal light transmitted through the high-transmittance, low-reflection dichroic mirror 203 and the reference light reflected by the high-transmittance, low-reflection dichroic mirror 203 are combined to form combined light.

[0027] The fast scanning Fourier spectrometer optical system 300 is used to generate time-dependent laser interference spectrum experimental data; the fast scanning Fourier spectrometer optical system 300 includes: a Fourier transform spectrometer, a balanced detector 307 , and a silicon avalanche photodetector 308 .

[0028] The Fourier transform spectrometer uses the principle of Michelson interferometer to split the combined light beams after being combined by the high-transmittance, low-reflection dichroic mirror 203 through the first thin-film beam splitter 301. The first thin-film beam splitter 301 is used for laser beam splitting. One beam is reflected 90 degrees by the first thin-film beam splitter 301, and the other beam is transmitted through the first thin-film beam splitter 301. After the first thin-film beam splitter 301 splits the beams, both the first transmitted light and the first reflected light contain signal light components and reference light components. The first transmitted light enters the hollow roof prism retro-reflective mirror assembly 302 to change the optical path length, and the first reflected light enters the hollow roof prism retro-reflective mirror assembly 302 to change the optical path length. The first transmitted light emitted from the hollow roof prism retroreflective mirror assembly 302 is split by the second thin film beam splitter 304 into a second transmitted light A and a second reflected light A. The first reflected light emitted from the hollow roof prism retroreflective mirror assembly 302 is split by the second thin film beam splitter 304 into a second transmitted light B and a second reflected light B. The second transmitted light A, the second transmitted light A, the second transmitted light B, and the second transmitted light B all contain a signal light component and a reference light component. The second transmitted light A and the second reflected light B are combined, and the signal light component in the second transmitted light A and the signal light component of the second reflected light B interfere to form a first interference signal light. The reference light component in the second transmitted light A and the reference light component of the second reflected light B interfere to form a first interference reference light. The first interference signal light and the first interference reference light are both input into the long-pass filter 305, and the long-pass filter 305 filters out the first interference reference light. The first interference signal light passes through the long-pass filter 305 and is detected by the first InAsSb photodetector in the balanced detector 307.

[0029] The second transmitted light B and the second reflected light A are combined, and the signal light component in the second transmitted light B and the signal light component of the second reflected light A interfere to form a second interference signal light. The reference light component in the second transmitted light B and the reference light component of the second reflected light A interfere to form a second interference reference light. After the second interference signal light and the second interference reference light are combined, they are incident on the short-pass filter 306. The second interference signal light is reflected by the short-pass filter 306 to the second InAsSb photodetector in the balanced detector 307 for detection. After the second interference reference light passes through the short-pass filter 306, it is incident on the silicon avalanche photodetector 308.

[0030] The first InAsSb photodetector and the second InAsSb photodetector of the balanced detector 307 utilize the differential detection principle to balance the first interference signal light and the second interference signal light and then subtract them, thereby reducing environmental noise and enhancing the interference signal.

[0031] The optical path difference of the first interference signal light is the same as the optical path difference of the second interference signal light, the optical path difference of the first interference reference light is the same as the optical path difference of the second interference reference light, and the same environmental disturbance is recorded.

[0032] In this embodiment, the splitting ratio of the first thin film beam splitter 301 and the second thin film beam splitter 304 in the mid-infrared band (signal light) is close to 1:1, and the splitting ratio of the reflected light and the transmitted light in the continuous light band (reference light) is 3:7.

[0033] The balanced detector 307 includes a first InAsSb photodetector and a second InAsSb photodetector. The first InAsSb photodetector and the second InAsSb photodetector are of the same model and are extremely sensitive to light in the mid-infrared band. The dark voltage signals of the first and second InAsSb photodetectors remain consistent in the absence of light.

[0034] The silicon avalanche photodetector 308 can detect wavelengths ranging from ultraviolet to near-infrared, and has multiple gears for adjusting the gain multiple, and is used to detect the second interference reference light.

[0035] In some embodiments, the hollow roof prism retroreflector assembly 302 includes a base, with a first hollow roof prism reflector assembly and a second hollow roof prism reflector assembly disposed on either side of the base. The first and second reflector assemblies are disposed laterally on either side of the base. Each hollow roof prism reflector in the first reflector assembly cooperates with each reflector in the first reflector assembly to cause the first transmitted light to repeatedly travel back and forth laterally and propagate forward (similar to the optical path of a square wave). Each hollow roof prism reflector in the second reflector assembly cooperates with each reflector in the second reflector assembly to cause the first reflected light to repeatedly travel back and forth laterally and propagate forward (similar to the optical path of a square wave). A linear motorized translation stage is used to drive the base in linear motion, thereby varying the distance between the first hollow roof prism reflector assembly and the first reflector assembly, and simultaneously varying the distance between the second hollow roof prism reflector assembly and the second reflector assembly, thereby simultaneously adjusting the optical path lengths of the first transmitted light and the first reflected light. The linear motorized translation stage has a displacement accuracy of 10 nm. The reflectors in the first and second reflector assemblies are silver mirrors.

[0036] The hollow roof prism retroreflective mirror assembly 302 is used to change the direction of laser transmission, reduce the influence of the vibration of the linear electric translation stage, and improve the stability of the optical path.

[0037] The translation stage control and data acquisition parallel processing module is used to control the movement of the linear electric translation stage 303 and also to control the high-speed data acquisition of the balance detector 307 and the silicon avalanche photodetector 308 .

[0038] The translation stage control and data acquisition parallel processing module includes: linear translation stage motion control module, data acquisition card group, synchronous clock continuous acquisition module, and dual-channel signal self-balancing processing and analysis module; The linear translation stage motion control module is a program written in LabView language and is used to control the motion of the linear electric translation stage 303; The data acquisition card set includes two data acquisition cards from NI. The first data acquisition card, model PXI-5922, is used to acquire signals from the first InAsSb photodetector (used to detect the first interference signal light) and the second InAsSb photodetector (used to detect the second interference signal light) in the balanced detector 307. The second data acquisition card, model PXIe-5122, is used to acquire signals from the silicon avalanche photodetector 308 (used for the second interference reference light).

[0039] The synchronous clock continuous acquisition module is a program written based on LabView language, which is used for clock synchronization of the first data acquisition card and the second data acquisition card.

[0040] The linear electric translation stage 303 starts accelerating to a set speed and maintains a constant scanning speed. At this point, the first and second data acquisition cards begin operating, collecting data from the balanced detector 307 and the silicon avalanche photodetector 308 and storing them in the internal RAM of the first and second data acquisition cards, respectively. When the RAM space is exhausted, the data is transferred to the computer's hard drive and the RAM space is cleared. This cycle of collection, storage, transfer, and clearing is repeated until the linear electric translation stage 303 decelerates and stops. Throughout the scanning and signal acquisition process, the linear electric translation stage 303 maintains a constant speed, enabling parallel processing between the linear electric translation stage 303 control and the two data acquisition cards.

[0041] The dual-channel signal self-balancing processing and analysis module is a program written in LabView. It is used to process and store the first interference signal light, the second interference signal light, and the second interference reference light signals generated during the uniform motion of the linear electric translation stage 303. The first InAsSb photodetector of the balanced detector 307 collects the first interference signal light, the second InAsSb photodetector of the balanced detector 307 collects the second interference signal light, and the silicon avalanche photodetector 308 collects the second interference reference light signal. Subsequently, the signals collected by the first and second InAsSb photodetectors of the balanced detector 307 are normalized and then subtracted to obtain self-balancing signals of the first and second interference signal lights. The second interference reference light signal collected by the silicon avalanche photodetector 308 is averaged, and this average value is subtracted from the second interference reference light signal to obtain a new interference spectrum that oscillates around zero. The time corresponding to the zero point of the new interference spectrum is extracted, and the self-balancing signal at the corresponding time is extracted to obtain half-wave resampled interference signal light data. The half-wave resampled interference signal light data is then Fourier transformed to obtain the final laser spectrum signal.

[0042] The purpose of the present invention is to utilize the parallel processing technology of interferometric rapid scanning and continuous data acquisition to synchronize and parallelize the motion control of the linear electric translation stage 303, the data acquisition of the balance detector 307 and the silicon avalanche photodetector 308, and the data storage of the first data acquisition card of the PXI-5922 model and the second data acquisition card of the PXIe-5122 model, so as to realize parallel processing of scanning signals, collecting data, storing data, and clearing cache, and realize continuous translational scanning in seconds, which greatly reduces the impact of unstable operation of the laser on the extraction of interference signals and improves the quality of interference spectrum sample acquisition and spectral resolution. The principle is that while the linear electric translation stage 303 is scanning at a constant speed, the first InAsSb photodetector of the balanced detector 307, the second InAsSb photodetector of the balanced detector 307, and the silicon avalanche photodetector 308 simultaneously acquire signals, and the first data acquisition card of the PXI-5922 model and the second data acquisition card of the PXIe-5122 model simultaneously store data. When the linear electric translation stage 303 ends its constant speed motion and enters the deceleration phase, the data stored in the RAM of the first data acquisition card of the PXI-5922 model and the second data acquisition card of the PXIe-5122 model are transferred to the computer, and the RAM cache of the first and second data acquisition cards is promptly cleared to provide sufficient space for the next data acquisition. Under the operation of the present invention, high-quality, high-sampling-rate interferometry spectra can be obtained within an acquisition time of seconds.

[0043] Example 2: A method for adaptive time calibration of a Fourier spectrometer using half-wave resampling is provided, using the method for adaptive time calibration of a Fourier spectrometer using half-wave resampling described in Example 1, comprising the following steps: Step 1: The first data acquisition card and the second data acquisition card perform clock synchronization; Step 2: The linear electric translation stage 303 starts and accelerates to the set speed while maintaining a constant scanning speed. The first data acquisition card collects the first interference signal light signal through the first InAsSb photodetector and stores it in the first data acquisition card's internal RAM. The first data acquisition card collects the second interference signal light signal through the second InAsSb photodetector and stores it in the first data acquisition card's internal RAM. The second data acquisition card collects the second interference reference light signal through the silicon avalanche photodetector 308 and stores it in the second data acquisition card's internal RAM. When the RAM storage space is exhausted, the data in the RAM is transferred to the computer hard drive and the RAM storage space is cleared. The above steps of collecting, storing, transferring, and clearing are repeated until the linear electric translation stage 303 begins to decelerate and stop. During the entire scanning and signal acquisition process, the linear electric translation stage 303 maintains a constant speed, achieving parallel processing of the linear electric translation stage 303 control and the two data acquisition cards. In step 3, the signals collected by the first and second InAsSb photodetectors are normalized and then subtracted to obtain the self-balanced signals of the first and second interference light signals. The second interference reference light signal collected by the silicon avalanche photodetector 308 is averaged, and this average is subtracted from the second interference reference light signal to obtain a new interference spectrum that oscillates around zero. The time corresponding to the zero point of the new interference spectrum is extracted, and the self-balanced signal at the corresponding time is extracted to obtain half-wave resampled interference light signal data. This half-wave resampled interference light signal data is then Fourier transformed to obtain the final laser spectrum signal, addressing the issue of beam drift and velocity drift affecting spectral accuracy and resolution during long-term laser operation.

[0044] Those skilled in the art will readily appreciate that the foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The present invention can be expanded to include other research areas, such as atoms, molecules, and materials, and can extend one-dimensional Fourier ultrafast spectroscopy to two-dimensional or even multi-dimensional Fourier ultrafast spectroscopy. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

[0045] It should be noted that the embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A device for adaptive time calibration of a Fourier spectrometer half-wave resampling, comprising a signal light and a reference light, characterized in that: The signal light sequentially passes through the gas absorption cell (201) and is combined with the reference light to form a combined light beam. The combined light beam is split by the first thin film beam splitter (301) to form a first transmitted light and a first reflected light. The first transmitted light and the first reflected light are both incident on the hollow roof prism retroreflective mirror group (302). The first transmitted light emitted by the hollow roof prism retroreflective mirror group (302) is further split by the second thin film beam splitter (304) into a second transmitted light A and a second reflected light A. The first reflected light emitted by the hollow roof prism retroreflective mirror group (302) is further split by the second thin film beam splitter (304) into a second transmitted light B and a second reflected light B. The second transmitted light A and the second reflected light B are combined into a beam, the signal light component in the second transmitted light A and the signal light component in the second reflected light B interfere to form a first interference signal light, and the reference light component in the second transmitted light A and the reference light component in the second reflected light B interfere to form a first interference reference light; the first interference reference light is filtered out by a long-pass filter (305), and the first interference signal light passes through the long-pass filter (305) and is detected by a first InAsSb photodetector. The second transmitted light B and the second reflected light A are combined, the signal light component in the second transmitted light B and the signal light component of the second reflected light A interfere to form a second interference signal light, and the reference light component in the second transmitted light B and the reference light component of the second reflected light A interfere to form a second interference reference light; the second interference signal light and the second interference reference light are combined and incident on a short-pass filter (306), the second interference signal light is reflected by the short-pass filter (306) to a second InAsSb photodetector for detection, and the second interference reference light is incident on a silicon avalanche photodetector (308) after transmitting through the short-pass filter (306).

2. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 1, characterized in that: The signal light passes through the aperture (103) and enters the gas absorption cell (201). The signal light exiting the gas absorption cell (201) passes through the beam reduction lens group (202) and is combined with the reference light passing through the aperture (103).

3. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 2, characterized in that: The beam reduction lens group (202) comprises a convex lens and a concave lens.

4. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 2, characterized in that: The hollow roof prism retroreflector group (302) comprises a base, a first hollow roof prism reflector group and a second hollow roof prism reflector group are arranged on both sides of the base, and a first reflector group and a second reflector group are arranged on both sides of the base, and each hollow roof prism reflector of the first hollow roof prism reflector group cooperates with each reflector of the first reflector group, so that the incident first transmitted light repeatedly travels back and forth horizontally and propagates forward; each hollow roof prism reflector of the second hollow roof prism reflector group cooperates with each reflector of the second reflector group, so that the incident first reflected light repeatedly travels back and forth horizontally and propagates forward.

5. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 4, characterized in that: The base is driven by a linear electric translation stage to move linearly, thereby changing the distance between the first hollow roof prism reflector group and the first reflector group, and simultaneously changing the distance between the second hollow roof prism reflector group and the second reflector group.

6. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 5, characterized in that: It also includes a translation stage linear reciprocating motion control module for controlling the motion of the linear electric translation stage (303).

7. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 6, characterized in that: It also includes a first data acquisition card for acquiring signals from the first InAsSb photodetector and the second InAsSb photodetector, and a second data acquisition card for acquiring signals from the silicon avalanche photodetector (308).

8. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 7, characterized in that: It also includes a synchronous clock continuous acquisition module for synchronizing the clocks of the first data acquisition card and the second data acquisition card.

9. The device for adaptive time calibration of a Fourier spectrometer using half-wave resampling according to claim 8, characterized in that: The invention also includes a dual-channel signal self-balancing processing and analysis module, which is used to perform normalization processing on the signals collected by the first InAsSb photodetector and the second InAsSb photodetector and then perform difference processing to obtain a self-balancing signal, calculate the average value of the second interference reference light signal collected by the silicon avalanche photodetector (308), subtract the above average value from the second interference reference light signal to obtain a new interference spectrum, extract the time corresponding to the zero point of the new interference spectrum, extract the self-balancing signal at the corresponding time to obtain half-wave resampled interference signal light data, perform Fourier transform on the half-wave resampled interference signal light data, and obtain the final laser spectrum signal.

10. A method for adaptive time calibration of a Fourier spectrometer using half-wave resampling, comprising the following steps: Step 1: The first data acquisition card and the second data acquisition card perform clock synchronization; Step 2, the linear electric translation stage (303) starts to accelerate to the set motion speed and maintains a uniform scanning speed, the first data acquisition card collects the signal of the first interference signal light through the first InAsSb photoelectric detector and stores it in the internal RAM of the first data acquisition card, the first data acquisition card collects the signal of the second interference signal light through the second InAsSb photoelectric detector and stores it in the internal RAM of the first data acquisition card, the second data acquisition card collects the signal of the second interference reference light through the silicon avalanche photoelectric detector (308) and stores it in the internal RAM of the second data acquisition card, when the RAM storage space is exhausted, the data in the RAM is transferred to the computer hard disk and the RAM storage space is cleared, and the above collection, storage, transfer, and clearing steps are repeated until the linear electric translation stage (303) starts to decelerate and stop. During the entire scanning and signal acquisition process, the linear electric translation stage (303) always maintains a uniform motion; Step 3: The signals collected by the first InAsSb photodetector and the second InAsSb photodetector are normalized and then subjected to difference processing to obtain a self-balanced signal, the second interference reference light signal collected by the silicon avalanche photodetector (308) is averaged, the second interference reference light signal is subtracted from the above average value to obtain a new interference spectrum oscillating up and down around the zero point, the time corresponding to the zero point of the new interference spectrum is extracted, the self-balanced signal at the corresponding time is extracted to obtain half-wave resampled interference signal light data, the half-wave resampled interference signal light data is Fourier transformed to obtain the final laser spectrum signal.

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