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CN-122016046-A - System and method for enhancing spectral demodulation rate of double-optical-frequency comb

CN122016046ACN 122016046 ACN122016046 ACN 122016046ACN-122016046-A

Abstract

The invention provides a system and a method for enhancing a dual-optical-frequency comb spectrum demodulation rate, wherein the system comprises a circulating light path, a unit to be tested, a light combining unit, a photoelectric detector and a data acquisition processing unit, wherein the circulating light path is used for splitting excitation pulse light input to the system and corresponding to a first repetition frequency, so that one part of the excitation pulse light is output towards the unit to be tested, the other part of the excitation pulse light circulates along the circulating light path, the unit to be tested is used for modulating the excitation pulse light, outputting processing signal light carrying dynamic spectrum information generated based on an actual dynamic spectrum of the unit to be tested, the light combining unit is used for coupling the processing signal light and sampling pulse light, the coupling signal light is output, the photoelectric detector is used for detecting the coupling signal light based on light field cross correlation, and the data acquisition processing unit is used for processing the periodic electric signal to obtain the actual dynamic spectrum of the corresponding unit to be tested. The invention at least improves the detection efficiency.

Inventors

  • YANG JIANJUN
  • JIA PINGGANG
  • WANG JUN

Assignees

  • 中北大学

Dates

Publication Date
20260512
Application Date
20251201

Claims (10)

  1. 1. An enhanced dual optical frequency comb spectral demodulation rate system comprising: a circulating light path configured to split excitation pulse light of a corresponding first repetition frequency input thereto such that a part of the excitation pulse light is output toward a unit to be measured and another part is circulated along the circulating light path; A unit to be measured configured to modulate excitation pulse light input thereto, and output processing signal light carrying dynamic spectrum information generated based on an actual dynamic spectrum of the unit to be measured; The light combining unit is configured to couple the processing signal light input to the light combining unit and the sampling pulse light corresponding to the second repetition frequency and output the coupled signal light, wherein a spectrum overlapping range exists between a first spectrum corresponding to the laser pulse light and a second spectrum corresponding to the sampling pulse light, and the spectrum overlapping range completely covers a spectrum response range of a corresponding unit to be detected; a photodetector configured to perform detection based on optical field cross-correlation on the coupled signal light input thereto, outputting a periodic electrical signal; The data acquisition processing unit is configured to process the periodic electric signals input to the data acquisition processing unit to obtain actual dynamic spectrums corresponding to the units to be detected.
  2. 2. The system of claim 1, wherein the system further comprises a controller configured to control the controller, The light combining unit comprises any one of an optical fiber coupler, a light splitting prism and a light splitting mirror.
  3. 3. The system of claim 1, wherein the system further comprises a controller configured to control the controller, The photoelectric detector comprises at least one of a PIN detector, an APD detector, a terahertz photoconductive antenna, a nonlinear optical crystal and a superconducting detector.
  4. 4. The method for enhancing the spectral demodulation rate of the double-optical-frequency comb is characterized by comprising the following steps of: splitting excitation pulse light input to the circulating light path and corresponding to the first repetition frequency based on the circulating light path, so that one part of the excitation pulse light is output towards the unit to be tested, and the other part of the excitation pulse light circulates along the circulating light path; Modulating excitation pulse light input to the unit to be tested based on the unit to be tested, and outputting processing signal light carrying dynamic spectrum information generated based on the actual dynamic spectrum of the unit to be tested; Coupling the processing signal light input to the light combining unit and the sampling pulse light corresponding to the second repetition frequency based on the light combining unit, and outputting the coupled signal light, wherein a spectrum overlapping range exists between a first spectrum corresponding to the laser pulse light and a second spectrum corresponding to the sampling pulse light, and the spectrum overlapping range completely covers a spectrum response range of a corresponding unit to be detected; Detecting the coupling signal light input to the photoelectric detector based on optical field cross correlation, and outputting a periodic electric signal; And processing the periodic electric signals input into the data acquisition processing unit based on the data acquisition processing unit to obtain the actual dynamic spectrum corresponding to the unit to be detected.
  5. 5. The demodulation method as claimed in claim 4, wherein, The circulating light path enables the excitation pulse light to make multiple round trips or turn back, so that the number of the excitation pulse light in unit time is increased. The optical path length of the circulating optical path is smaller than the cavity length of the laser corresponding to the emergent exciting pulse light, and the optical path length of the circulating optical path is larger than the optical path length of the exciting pulse light.
  6. 6. The demodulation method as claimed in claim 4, wherein, The circulating light path enables the excitation pulse light to make multiple round trips or turn back, the number of round trips or turn back N is the relation of M=N+1 of the number M and N of the signal pulse light lifted in unit time, wherein the ratio of the cavity length of the laser corresponding to the emergent excitation pulse light to the optical path length of the circulating light path is downwards positive.
  7. 7. The method of claim 6, wherein the step of providing the first layer comprises, Modulating the excitation pulse light input to the unit to be tested based on the unit to be tested, and outputting processing signal light carrying dynamic spectrum information generated based on the actual dynamic spectrum of the unit to be tested, wherein the processing signal light comprises the following components: responding to excitation pulse light to be input into a unit to be detected, and modulating a linear optical process and/or a nonlinear optical process on the excitation pulse light based on the unit to be detected so as to determine the frequency spectrum change generated by the actual dynamic spectrum of the corresponding unit to be detected based on the excitation pulse light; dynamic spectral information is generated based on the spectral variation to output processing signal light carrying the dynamic spectral information.
  8. 8. The method of claim 6, wherein the step of providing the first layer comprises, The periodic electric signals input to the data acquisition processing unit are processed based on the data acquisition processing unit to obtain the actual dynamic spectrum corresponding to the unit to be detected, and the method comprises the following steps: denoising the periodic electric signal input to the data acquisition processing unit based on the data acquisition processing unit to obtain a denoising processing signal, wherein the denoising processing comprises at least one of denoising methods based on wavelet transformation, independent component analysis, empirical mode decomposition, principal component analysis and phase matching; And performing spectrum acquisition processing on the denoising processing signal to obtain an actual dynamic spectrum of a corresponding unit to be detected, wherein the spectrum acquisition processing comprises at least one of fast convolution, fourier transformation, fourier inverse transformation, short-time Fourier transformation, wavelet transformation, hilbert-Huang transformation, sinusoidal curve fitting, rake wavelet matching, S transformation, cohen bilinear transformation, adaptive filtering and maximum likelihood estimation.
  9. 9. The method of claim 6, wherein the step of providing the first layer comprises, Splitting excitation pulse light input to the circulating optical path at a first repetition frequency based on the circulating optical path, so that one part of the excitation pulse light is output towards a unit to be tested, and the other part of the excitation pulse light circulates along the circulating optical path, wherein the method further comprises the following steps: Acquiring a detection period of a corresponding unit to be detected, which is input by a management end, and determining a reference light path length of a corresponding circulating light path based on the detection period; Determining a first fixed section and a second fixed section which form a circulating light path, wherein a first end part of the first fixed section receives the excitation pulse light, a third end part of the second fixed section is connected with a second end part of the first fixed section, and a fourth end part of the second fixed section is connected with the first end part; Responding to the light path difference value of the corresponding negative value attribute of the fixed length of the first fixed section and the second fixed section and the reference light path length, controlling the mechanical end to disconnect the third end part from the second end part so as to form a customized accommodating area, and setting the light splitting units with the corresponding splitting number of two to be connected with the second end part by the splitting input end included in the light splitting units; And determining an optical fiber custom section based on the optical path difference value, and controlling the mechanical arm to connect a fifth end part of the optical fiber custom section with a first output end included in the light splitting unit and connect a sixth end part of the optical fiber custom section with the third end part so as to position the optical fiber custom section in the custom accommodation area, wherein a second output end included in the light splitting unit faces towards the unit to be tested.
  10. 10. The method of claim 9, wherein the step of determining the position of the substrate comprises, The method further comprises the steps of: Determining the circulating light path as a main level light path in response to the light path difference value of the corresponding positive value attribute of the fixed length of the first fixed section and the second fixed section and the reference light path length; The control mechanical end disconnects the third end part from the second end part to form a customized accommodating area, and sets the light splitting units with the corresponding splitting number of three as light splitting input ends included in the light splitting units to be connected with the second end part; determining an optical fiber custom section based on the reference optical path length, and controlling a mechanical arm to connect a fifth end part of the optical fiber custom section to a first output end included in a light splitting unit and a sixth end part to the third end part so as to position the optical fiber custom section in a custom accommodation area, wherein a second output end included in the light splitting unit faces towards a unit to be tested; Determining a third fixed section and a fourth fixed section which form a secondary light path and correspond to a fixed length, wherein a seventh end part of the third fixed section receives the excitation pulse light, a ninth end part of the fourth fixed section is connected with an eighth end part of the third fixed section, and a tenth end part of the fourth fixed section is connected with the seventh end part; The control mechanical arm connects the eighth end part to a light splitting input end included in the light splitting unit, and connects the ninth end part to a third output end included in the light splitting unit.

Description

System and method for enhancing spectral demodulation rate of double-optical-frequency comb Technical Field The invention relates to the technical field of spectrum detection, in particular to a system and a method for enhancing a dual-optical-frequency comb spectrum demodulation rate. Background In field applications such as laboratory research, chemical sensing, aerospace, atmospheric monitoring and the like, rapid and high-precision spectral measurement is important for material analysis and mechanical measurement. With the continuous development of frequency comb technology, double-comb spectroscopy has been developed, and has become a revolutionary method in the field of optical spectroscopy. Double comb spectroscopy is similar to fourier transform infrared spectroscopy (FTIR), but unlike conventional FTIR, a fast and highly sensitive wide-range, high-resolution linear absorption spectroscopy measurement can be achieved without the use of any moving optical elements. In addition, the development of micro-resonance optical frequency comb, single-cavity double-optical frequency comb, electro-optical modulation optical frequency comb and other technologies makes the double-comb spectroscopy system more compact and can be conveniently deployed in field application. By virtue of the unique advantages, the double-comb spectroscopy is not only suitable for basic scientific research, but also widely applied to a plurality of actual scenes outside a laboratory. In double-comb spectroscopy, one frequency comb (the signal comb) is used to excite the spectral response of the sample under test, and the other frequency comb (the reference comb) samples the signal comb in the time domain, thereby obtaining an interferogram. Because of the small difference of the repetition frequencies of the two frequency combs, the high-frequency optical signals which cannot be directly detected by the electronic equipment can be converted into the processable radio-frequency signals through an asynchronous sampling technology. In static measurement, double comb spectroscopy obtains a spectrum with a high signal-to-noise ratio by averaging single measurements in the time domain or spectral domain, so as to reveal fine structures in the spectrum, which is also one of its main advantages. However, in many application scenarios, dynamic spectral changes need to be monitored in real time on different time scales, which puts higher demands on double comb spectroscopy. Therefore, it is desirable to provide a system and method for enhancing the spectral demodulation rate of a dual optical frequency comb, which can improve the detection efficiency. Disclosure of Invention The present invention has been made in view of the above problems, and it is an object of the present invention to provide an enhanced dual optical frequency comb spectral demodulation rate system and method that overcomes or at least partially solves the above problems. According to one aspect of the present invention, there is provided an enhanced dual optical frequency comb spectral demodulation rate system comprising: a circulating light path configured to split excitation pulse light of a corresponding first repetition frequency input thereto such that a part of the excitation pulse light is output toward a unit to be measured and another part is circulated along the circulating light path; A unit to be measured configured to modulate excitation pulse light input thereto, and output processing signal light carrying dynamic spectrum information generated based on an actual dynamic spectrum of the unit to be measured; The light combining unit is configured to couple the processing signal light input to the light combining unit and the sampling pulse light corresponding to the second repetition frequency and output the coupled signal light, wherein a spectrum overlapping range exists between a first spectrum corresponding to the laser pulse light and a second spectrum corresponding to the sampling pulse light, and the spectrum overlapping range completely covers a spectrum response range of a corresponding unit to be detected; a photodetector configured to perform detection based on optical field cross-correlation on the coupled signal light input thereto, outputting a periodic electrical signal; The data acquisition processing unit is configured to process the periodic electric signals input to the data acquisition processing unit to obtain actual dynamic spectrums corresponding to the units to be detected. Optionally, in the system according to the present invention, the sampling pulse light and the excitation pulse light are any one of ultraviolet pulse light, visible pulse light, infrared pulse light, X-ray pulse light, multi-wavelength tunable pulse light, and terahertz pulse light. Optionally, in the system according to the invention, the sampling pulse light and the excitation pulse light are directly output via at least one laser; Or alternatively The output is m