Apparatus and method for fourier spectrometer half-wave resampling adaptive time calibration

Abstract

The application discloses a Fourier spectrometer half-wave resampling adaptive time calibration device, comprising a laser output module, a long optical path gas absorption cell module, a fast scanning Fourier spectrometer optical system, a displacement table control and data acquisition parallel processing module, and discloses a Fourier spectrometer half-wave resampling adaptive time calibration method.The application realizes parallel processing of scanning signals, data acquisition, data storage and emptying of a cache through the displacement table control and data acquisition parallel processing module, realizes second-level continuous scanning in a translation mode, solves the problem of non-uniform change of sampling point optical path differences under long-range scanning of a linear electric displacement table, and is favorable for improving the signal-to-noise ratio and resolution of laser spectrum and absorption spectrum.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ultrafast molecular spectroscopy, and particularly relates to a device and method for half-wave resampling adaptive time calibration of a Fourier spectrometer. BACKGROUND

[0002] The Fourier spectroscopy is a kind of double-beam interference spectroscopy, which utilizes the principle of a Michelson interferometer to generate interference light, and then the interference light interacts with a sample, so that the absorption spectrum information of the sample is loaded into the interference light. The scanning time-dependent interference spectrum is Fourier transformed to obtain the absorption spectrum of the sample. This technology can detect and identify the unique vibration-rotation energy level structure of molecules, and is commonly used for detecting the composition and corresponding concentration of a sample, and has the characteristics of high sensitivity, high resolution and high precision, and is widely used in many fields such as human health, environmental protection, industrial production and atmospheric detection. With the continuous development of Fourier spectroscopy, its spectral range is continuously expanding, and its measurement precision is continuously improving.

[0003] One of the keys to obtaining broadband Fourier ultrafast spectroscopy with high precision and high resolution is to collect interference signal data with enough sample points and a large enough scanning range. In order to collect more sample points, a continuous scanning method has been developed, that is, the scanning range is scanned once at a specified speed, the displacement platform accelerates from the starting point of the scanning to the specified speed and then becomes uniform motion, and when the displacement platform approaches the scanning end position, it decelerates to a stationary state. The displacement platform collects and stores the complete interference data obtained by scanning during the movement. However, due to the voltage fluctuation of the pump light source and the influence of temperature change on the gain medium caused by long-time work, the light beam will drift when the laser works for a long time. At the same time, the displacement platform will experience non-uniform motion of acceleration and deceleration when it is just started and about to stop, and there is also drift of the running speed in the uniform motion stage. The above factors will cause non-uniform distribution of the sample points of the collected interference signal in the optical delay, thereby reducing the quality of the interference signal and further affecting the spectral precision and resolution. SUMMARY

[0004] The purpose of the present application is to provide a device and method for half-wave resampling adaptive time calibration of a Fourier spectrometer to solve the above problems in the prior art.

[0005] The above purpose of the present application is achieved by the following technical means:

[0006] The device of Fourier spectrometer half-wave resampling adaptive time calibration comprises signal light and reference light, the signal light passes through a gas absorption cell in sequence and is combined with the reference light to form combined light, the combined light is split by a first thin film beam splitter to form first transmitted light and first reflected light, the first transmitted light and the first reflected light are incident into a hollow ridge prism mirror group, the first transmitted light emitted from the hollow ridge prism mirror group is split by a second thin film beam splitter into second transmitted light A and second reflected light A, the first reflected light emitted from the hollow ridge prism mirror group is split by the second thin film beam splitter into second transmitted light B and second reflected light B,

[0007] The second transmitted light A and the second reflected light B are combined, the signal light component in the second transmitted light A and the signal light component of the second reflected light B interfere to form first interference signal light, and the reference light component in the second transmitted light A and the reference light component of the second reflected light B interfere to form first interference reference light; the first interference reference light is filtered out by a long-pass filter, and the first interference signal light passes through the long-pass filter and is detected by a first InAsSb photodetector,

[0008] 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 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 second interference reference light; the second interference signal light and the second interference reference light are combined and then incident into a short-pass filter, the second interference signal light is reflected by the short-pass filter to a second InAsSb photodetector for detection, and the second interference reference light is transmitted through the short-pass filter and then incident into a silicon avalanche photodetector.

[0009] The signal light passes through an aperture and then is incident into the gas absorption cell, and the signal light emitted from the gas absorption cell passes through a beam-reducing lens group and is combined with the reference light passing through the aperture.

[0010] The beam-reducing lens group comprises a convex lens and a concave lens.

[0011] The hollow ridge prism mirror group comprises a base, a first hollow ridge prism mirror group and a second hollow ridge prism mirror group are arranged on two sides of the base, a first mirror group and a second mirror group are arranged on the sides of the base, each hollow ridge prism mirror of the first hollow ridge prism mirror group and each mirror of the first mirror group are matched, so that the incident first transmitted light repeatedly transversely goes back and forth and propagates forward, and each hollow ridge prism mirror of the second hollow ridge prism mirror group and each mirror of the second mirror group are matched, so that the incident first reflected light repeatedly transversely goes back and forth and propagates forward.

[0012] The base station is driven by a linear motorized displacement stage to move linearly, thereby changing the distance between the first hollow ridge prism mirror group and the first mirror group, and simultaneously changing the distance between the second hollow ridge prism mirror group and the second mirror group.

[0013] The displacement stage linear reciprocating motion control module for controlling the motion of the linear motorized displacement stage is further included.

[0014] The first data acquisition card for signal acquisition of the first InAsSb photodetector and the second InAsSb photodetector is further included, and the second data acquisition card for signal acquisition of the silicon avalanche photodetector is further included.

[0015] The synchronous clock continuous acquisition module for clock synchronization of the first data acquisition card and the second data acquisition card is further included.

[0016] The dual-channel signal self-balancing processing and analysis module is further included, which is used for performing difference processing on the normalized signals collected by the first InAsSb photodetector and the second InAsSb photodetector to obtain a self-balancing signal, performing averaging on the second interference reference light signal collected by the silicon avalanche photodetector, subtracting the second interference reference light signal from the above-mentioned average value to obtain a new interference spectrum, extracting the time corresponding to the zero point of the new interference spectrum, extracting the self-balancing signal at the corresponding time to obtain a half-wave resampled interference signal light data, and performing Fourier transform on the half-wave resampled interference signal light data to obtain a final laser spectrum signal.

[0017] The method for half-wave resampling adaptive time calibration of a Fourier spectrometer, comprising the following steps:

[0018] Step 1, the first data acquisition card and the second data acquisition card are clock-synchronized;

[0019] Step 2, the linear motorized displacement stage is started to accelerate to a set motion speed and keep uniform speed scanning, the first data acquisition card collects the signal of the first interference signal light through the first InAsSb photodetector and stores it to 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 to 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 to the internal RAM of the second data acquisition card, when the RAM storage space is almost full, the data in the RAM is transferred to the computer hard disk and the RAM storage space is emptied, the above-mentioned acquisition, storage, transfer and emptying steps are repeated, until the linear motorized displacement stage starts to decelerate and stop, and during the whole scanning and signal acquisition process, the linear motorized displacement stage keeps uniform motion;

[0020] Step 3, the signals collected by the first InAsSb photodetector and the second InAsSb photodetector are subjected to difference processing after normalization processing to obtain a self-balancing signal, the second interference reference light signal collected by the silicon avalanche photodetector is averaged, the second interference reference light signal is subtracted from the average value to obtain a new interference spectrum oscillating up and down around zero point, 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 a half-wave resampled interference signal light data, and the half-wave resampled interference signal light data is subjected to Fourier transform to obtain a final laser spectrum signal.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The present application realizes parallel processing of scanning signals, data collection, data storage, and cache emptying through displacement table control and data collection parallel processing modules, realizes second-level continuous scanning, and obtains a self-balancing signal through difference processing of the first interference signal light and the second interference signal light after normalization processing, obtains a new interference spectrum based on the second interference reference light signal, extracts the time corresponding to the zero point of the new interference spectrum, extracts the self-balancing signal at the corresponding time to obtain half-wave resampled interference signal light data, greatly reduces the influence of unstable operation of the laser on the extraction of the interference signal, and improves the interference spectrum sample collection quality and spectral resolution. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The optical path principle diagram of the present application is shown in the figure;

[0024] Among them, 100: laser output module; 101: mid-infrared femtosecond laser frequency comb light source; 102: helium-neon continuous laser; 103: diaphragm; 200: long optical path gas absorption cell module; 201: gas absorption cell; 202: beam-reducing lens group; 203: high-transmission low-reflection dichroic mirror; 300: fast scanning Fourier spectrometer optical system; 301: first thin film beam splitter; 302: hollow ridge prism mirror group; 303: linear motorized displacement table; 304: second thin film beam splitter; 305: long-pass filter; 306: short-pass filter; 307: balanced detector; 308: silicon avalanche photodetector. DETAILED DESCRIPTION

[0025] In order to facilitate those skilled in the art to understand and implement the present application, the present application is further described in detail below in conjunction with examples, and the examples described herein are only used to illustrate and explain the present application, and are not a limitation on the present application.

[0026] Example 1:

[0027] The device of Fourier spectrometer half-wave resampling adaptive time calibration comprises a laser output module 100, a long optical path gas absorption cell module 200 (Herriott long optical path gas absorption cell module is adopted in the embodiment), a fast scanning Fourier spectrometer optical system 300, a displacement table control and data acquisition parallel processing module, and a computer 400. Figure 1 .

[0028] The laser output module 100 comprises a mid-infrared femtosecond laser frequency comb light source 101 for generating interaction with sample gas, a helium-neon continuous laser 102 serving as an intermediate phase reference for laser phase correction, and an aperture 103.

[0029] The output laser wavelength range of the mid-infrared femtosecond laser frequency comb light source 101 is 3.2-3.7 μm, the pulse width is 150 fs, and the repetition frequency is 200 MHz. The covered 3.2-3.5 μm mid-infrared waveband contains key molecular absorption spectra of methane, hydrogen sulfide, acetylene, OCS and other fields related to environmental pollution and human health. It is used for interaction with sample gas, and the vibration-rotation energy level absorption spectrum information of the sample gas is loaded into the laser spectrum, so it can also be called signal light.

[0030] The output laser wavelength of the helium-neon continuous laser 102 is 632.8 nm continuous light. The 632.8 nm helium-neon continuous laser 102 outputs visible light, which is far enough from the mid-infrared waveband, so that the beam combination of the signal light and the reference light can be separated by coating of different materials, and it is used to provide an equally spaced phase reference for the phase correction of the light field in the laser propagation, so it can also be called reference light.

[0031] The aperture 103 is used for pointing calibration of the lasers output by the mid-infrared femtosecond laser frequency comb light source 101 and the helium-neon continuous laser 102, and filtering of excess stray light.

[0032] The long optical path gas absorption cell module 200 provides a vacuum sealed environment for laser interaction with sample gas, and is the source of molecular absorption spectrum signals detected by the Fourier spectrometer. The long optical path gas absorption cell module 200 comprises a gas absorption cell 201, a beam-reducing lens group 202 and a high-transmission low-reflection dichroic mirror 203.

[0033] The gas absorption cell 201 (Herriott gas absorption cell is adopted in the embodiment) is a place for interaction of signal light with 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 jump to the corresponding vibration-rotation energy level, thereby leaving obvious absorption lines in the signal light spectrum, and obtaining the absorption spectrum of the sample molecule.

[0034] The gas absorption cell 201 comprises an absorption cell, two light transmission holes on the absorption cell are respectively sealed with an incident window piece and an exit window piece, the incident window piece and the exit window piece are made of ZnSe, so that a sealed environment is formed in the absorption cell, a plurality of gold film mirrors with fixed position and fixed reflection angle are embedded in the absorption cell, the signal light enters the absorption cell from the incident window piece after the diaphragm 103, and the signal light is reflected by the gold film mirrors and propagates in the absorption cell for 500 cm, and then transmits through the exit window piece to leave the absorption cell, the signal light interacts with the sample gas in the absorption cell during the long-distance propagation, and absorbs photons with a frequency corresponding to the molecular vibration-rotation energy level, which is the source of the molecular absorption spectrum signal detected by the Fourier spectrometer.

[0035] The condensing lens group 202 comprises a convex lens and a concave lens, the convex lens and the concave lens form a telescope system, and the signal light emitted from the absorption cell is condensed to reduce the signal light spot size from 13 mm to 3 mm. Since the signal light transmits in the gas absorption cell for five meters, the light spot inevitably diverges, in order to retain the complete absorption spectrum information while condensing, the condensing lens group 202 instead of the diaphragm is used to control the light spot size.

[0036] The high-transmission low-reflection dichroic mirror 203 is coated with a long-wave high-transmission short-wave high-reflection laser response material, and takes 950 nm as the boundary, 95% of the signal light with a longer wavelength is highly transmitted, and 95% of the reference light with a shorter wavelength is highly reflected, so as to realize the condensing of the signal light and the reference light, the signal light condensed by the condensing lens group 202 transmits through the high-transmission low-reflection dichroic mirror 203, the reference light emitted from the diaphragm 103 is reflected by the high-transmission low-reflection dichroic mirror 203, and the signal light transmitting through the high-transmission low-reflection dichroic mirror 203 and the reference light reflected by the high-transmission low-reflection dichroic mirror 203 form the combined light.

[0037] The fast scanning Fourier spectrometer optical system 300 is used to generate time-dependent laser interference spectrum experimental data, and comprises a Fourier transform spectrometer, a balanced detector 307 and a silicon avalanche photodetector 308.

[0038] The Fourier transform spectrometer utilizes the principle of the Michelson interferometer, so that the combined light after the condensing by the high-transmission low-reflection dichroic mirror 203 transmits through the first thin-film beam splitter 301 after the condensing, the first thin-film beam splitter 301 is used for laser beam splitting, one beam is reflected by 90 degrees, and the other beam transmits through the first thin-film beam splitter 301, the first transmitted light and the first reflected light both contain signal light components and reference light components after the condensing of the first thin-film beam splitter 301,

[0039] The first transmitted light changes the optical path length by being incident on the hollow ridge prism mirror group 302, and the first reflected light changes the optical path length by being incident on the hollow ridge prism mirror group 302,

[0040] The first transmitted light exiting the hollow ridge prism retroreflector group 302 is split into second transmitted light A and second reflected light A by the second thin film beam splitter 304, and the first reflected light exiting the hollow ridge prism retroreflector group 302 is split into second transmitted light B and second reflected light B by the second thin film beam splitter 304, the second transmitted light A, the second transmitted light A, the second transmitted light B and the second transmitted light B all contain signal light components and reference light components,

[0041] The second transmitted light A and the second reflected light B are combined, the signal light component in the second transmitted light A and the signal light component of the second reflected light B interfere to form first interference signal light, and the reference light component in the second transmitted light A and the reference light component of the second reflected light B interfere to form first interference reference light; the first interference signal light and the first interference reference light are both input into the long-pass filter 305, the long-pass filter 305 filters out the first interference reference light, and 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.

[0042] 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 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 second interference reference light; the second interference signal light and the second interference reference light are combined and then 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, and the second interference reference light transmits the short-pass filter 306 and then is incident on the silicon avalanche photodetector 308.

[0043] The first InAsSb photodetector and the second InAsSb photodetector of the balanced detector 307 use differential detection principle to subtract the first interference signal light and the second interference signal light after balanced processing, which can reduce environmental noise and enhance the interference signal.

[0044] The optical path difference of the first interference signal light is the same as that of the second interference signal light, the optical path difference of the first interference reference light is the same as that of the second interference reference light, and the same environmental disturbance is recorded.

[0045] In the present embodiment, the first thin film beam splitter 301 and the second thin film beam splitter 304 have a reflection-to-transmission ratio close to 1:1 in the mid-infrared waveband (signal light), and a reflection-to-transmission ratio of 3:7 in the continuous light waveband (reference light).

[0046] The balance detector 307 comprises 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 the mid-infrared waveband, and the dark voltage signals are consistent in the absence of light.

[0047] The silicon avalanche photodetector 308 can detect ultraviolet to near-infrared wavelengths, and has multiple gears to adjust the gain multiple, for detecting the second interference reference light.

[0048] In some embodiments, the hollow ridge prism mirror group 302 comprises a base, the first hollow ridge prism mirror group and the second hollow ridge prism mirror group are arranged on the two sides of the base, the first mirror group and the second mirror group are arranged on the two sides of the base, the hollow ridge prism mirrors of the first hollow ridge prism mirror group are matched with the mirrors of the first mirror group, so that the first transmitted light repeatedly transversely returns and propagates forward (similar to a square wave light path); the hollow ridge prism mirrors of the second hollow ridge prism mirror group are matched with the mirrors of the second mirror group, so that the first reflected light repeatedly transversely returns and propagates forward (similar to a square wave light path), the linear motorized displacement stage is used to drive the linear motion of the base, thereby changing the distance between the first hollow ridge prism mirror group and the first mirror group, and simultaneously changing the distance between the second hollow ridge prism mirror group and the second mirror group, to achieve the purpose of simultaneously adjusting the optical path of the first transmitted light and the first reflected light. The displacement accuracy of the linear motorized displacement stage is 10 nm. The mirrors in the first mirror group and the second mirror group are silver mirrors.

[0049] The hollow ridge prism mirror group 302 is used to change the direction of laser transmission, and to reduce the influence of linear motorized displacement stage vibration, and to improve the stability of the optical path.

[0050] The displacement stage control and data acquisition parallel processing module is used to control the motion of the linear motorized displacement stage 303, and is also used to control the high-speed data acquisition of the balance detector 307 and the silicon avalanche photodetector 308.

[0051] The displacement stage control and data acquisition parallel processing module comprises a linear displacement stage motion control module, a data acquisition card group, a synchronous clock continuous acquisition module, and a double-channel signal self-balancing processing and analysis module.

[0052] The linear displacement stage motion control module is a program written based on LabView language, and is used to control the motion of the linear motorized displacement stage 303.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] The present application aims to synchronize and parallelize the motion control of the linear motorized displacement stage 303, the data collection of the balance detector 307 and the silicon avalanche photodetector 308, and the data storage of the first data acquisition card of PXI-5922 model and the second data acquisition card of PXIe-5122 model, to realize the parallel processing of scanning signals, collected data, stored data, and emptying the cache, to realize the second-order continuous scanning, and to greatly reduce the impact of unstable operation of the laser on the extraction of interference signals, and to improve the quality of interference spectrum sample collection and spectral resolution. The principle is that while the linear motorized displacement stage 303 is uniformly scanned, the first InAsSb photodetector of the balance detector 307, the second InAsSb photodetector of the balance detector 307, and the silicon avalanche photodetector 308 are synchronized to collect signals, and the first data acquisition card of PXI-5922 model and the second data acquisition card of PXIe-5122 model are synchronized to store data; when the linear motorized displacement stage 303 uniformly moves into the deceleration stage, the data stored in the RAM of the first data acquisition card of PXI-5922 model and the second data acquisition card of PXIe-5122 model are transferred to the computer, and the first and second data acquisition card RAM caches are emptied in time to provide enough space for the collection of the next data. Under the operation of the present application, high-quality and high-sampling-rate interference spectra are obtained within a collection time of seconds.

[0058] Embodiment 2:

[0059] The method for Fourier spectrometer half-wave resampling adaptive time calibration, using the method for Fourier spectrometer half-wave resampling adaptive time calibration in embodiment 1, comprises the following steps:

[0060] Step 1, the first data acquisition card and the second data acquisition card are clock synchronized;

[0061] Step 2, the linear motorized displacement stage 303 starts to accelerate to the set motion speed and keeps uniform speed scanning, the first data acquisition card collects the signal of the first interference signal light through the first InAsSb photodetector and stores it to 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 to 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 308 and stores it to the internal RAM of the second data acquisition card. When the RAM storage space is almost full, the data in the RAM is transferred to the computer hard disk and the RAM storage space is emptied, and the above collection, storage, transfer and emptying steps are repeated until the linear motorized displacement stage 303 starts to decelerate and stop. During the whole scanning and signal collection process, the linear motorized displacement stage 303 always keeps uniform motion, realizing parallel processing of the linear motorized displacement stage 303 control and the two data acquisition cards;

[0062] Step 3, the signals collected by the first InAsSb photodetector and the second InAsSb photodetector are subjected to difference processing after normalization processing, that is, the self-balancing signal of the first interference signal light and the second interference signal light can be obtained. The average value of the second interference reference light signal collected by the silicon avalanche photodetector 308 is calculated, and then the second interference reference light signal is subtracted from the average value, that is, the new interference spectrum oscillating up and down around zero can be obtained. 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 the half-wave resampled interference signal light data. Then, the Fourier transform of the half-wave resampled interference signal light data is performed, and the final laser spectrum signal can be obtained, solving the problem that the drift of the light beam and the drift of the running speed of the laser during long-time work affect the spectral accuracy and resolution.

[0063] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. The present application can be extended to other atomic, molecular, material research fields, and can be extended to two-dimensional or even multi-dimensional Fourier ultrafast spectroscopy. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

[0064] It should be noted that the embodiments described in the present application are only examples to illustrate the spirit of the present application. Those skilled in the art can make various modifications or supplements to the described embodiments or use similar ways to replace them without deviating from the spirit of the present application or exceeding the scope defined by 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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