Method and system for calibrating spectral width of frequency-modulated laser pulses based on traversal correlation

Abstract

The application discloses a frequency-modulated laser pulse spectrum width calibration method and a calibration system based on a traversal correlation algorithm, and belongs to the field of laser signal processing. The frequency-modulated laser pulse spectrum width calibration method draws a first relationship curve between a measured spectrum width and a calibration spectrum width based on measurement data, and finally determines the calibration spectrum width of a subsequent laser pulse to be measured by using the first relationship curve. The application establishes a connection between a medium-precision measurement spectrum and a theoretical simulation spectrum, the calibrated spectrum width more reflects the physical nature of phase modulation relative to the -3dB spectrum width, and the data obtained by the calibration method and the calibration system has strong correlation (R>0.9), high linearity and high confidence, and the data is more reliable. Meanwhile, the calibration method and the calibration system provided by the application reduce the use frequency of a high-precision spectrometer, reduce the use cost, reduce the dependence on high-end instruments, and have high economic value.

Description

Technical Field

[0001] This invention belongs to the field of laser signal processing, specifically relating to a method and system for calibrating the spectral width of frequency-modulated laser pulses based on ergodic correlation. Background Technology

[0002] High-power lasers can create unprecedentedly strong electric fields, strong magnetic fields, and high pressures in laboratory environments, playing an irreplaceable role in many cutting-edge scientific and technological fields such as inertial confinement fusion, high-energy-density physics, and astrophysics. On December 25, 2022, the US National Energy Facility (NIF) achieved an energy gain of Q≈1.54, successfully realizing laser fusion. During this process, the NIF device precisely adjusted the spectral dimensions, tuning the wavelengths of the inner and outer rings by 0.025 nm. This minute wavelength change resulted in a more uniform X-ray radiation field within the cavity, leading to a more symmetrical implosion and burning approximately 4% of the fuel, a 100% increase compared to the 2% burned on August 8, 2021. This demonstrates that precision physics experiments are highly sensitive to spectral changes, and precise spectral control can achieve significant physical effects. In high-power laser devices, to suppress transverse stimulated Brillouin scattering (TSBS) caused by large-aperture fused silica optical elements under narrow bandwidth operating conditions, waveguide phase modulation technology is required in the laser injection system to convert single-longitudinal-mode laser light into frequency-modulated laser light. This distributes the pulse energy across multiple modes with a mode spacing exceeding the TSBS bandwidth, ensuring that the peak power of each mode is below the TSBS threshold. To achieve precise global control of high-power laser devices and meet the needs of precision physics experiments, the spectral width of the frequency-modulated laser pulse needs to be accurately obtained.

[0003] The single-mode laser pulse emitted from the front-end system is phase-modulated and broadened into a comb-shaped spectrum with a separated symmetrical distribution, becoming a frequency-modulated laser pulse. During transmission in subsequent laser links, the frequency-modulated laser pulse is affected by non-uniform spectral transmittance, causing its spectral shape to change and no longer exhibit a perfectly symmetrical distribution. Furthermore, the spectrum of the frequency-modulated laser pulse has a complex comb-shaped distribution, whose characteristics are inconsistent with a typical continuous spectrum. High-precision spectrometers can resolve the comb-shaped spectral distribution, but they struggle to accurately measure the discrete amplitudes of the comb-shaped spectrum. In addition, high-precision spectrometers operate under harsh conditions, their spectral resolution decreases after repeated handling, and their operating costs are high.

[0004] On the other hand, while medium-precision spectrometers are relatively robust and reliable, and can obtain the contour envelope and -3dB spectral width of comb-shaped spectra, they are insufficient to reflect the spectral morphology and essential properties. High-power laser devices typically consist of dozens or even hundreds of laser beams, requiring spectral width calibration of each sub-beam before each round of physics experiments, necessitating frequent movement of the spectrometer. Therefore, how to calibrate the comb-shaped spectral width of frequency-modulated laser pulses using only a commonly available medium-precision spectrometer in laboratories is a major challenge limiting the improvement of precise spectral control in high-power lasers. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems. Based on the characteristics of the comb spectrum of frequency-modulated laser pulses, this invention proposes a method and system for calibrating the spectral width of frequency-modulated laser pulses based on an ergodic correlation algorithm, and analyzes the width of the comb spectrum of frequency-modulated laser pulses.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for calibrating the spectral width of frequency-modulated laser pulses based on ergodic correlation is disclosed for calibrating the spectral width of discrete comb-shaped frequency-modulated lasers. The method includes: performing measurements on a series of frequency-modulated laser pulses under different radio frequency amplitude conditions using a first and a second measuring spectrometer, respectively, and obtaining measurement data; determining the effective spectral range and extracting the effective spectral data from the measurement data; performing spectral correlation ergodic calculation and obtaining the correlation calculation results; determining the maximum correlation calculation value and the optimal matching spectral width corresponding to the maximum correlation calculation value from all correlation ergodic calculation results; plotting a first relationship curve between the measured spectral width and the calibrated spectral width; and finally using the first relationship curve to determine the calibrated spectral width of subsequent laser pulses to be measured.

[0008] On the other hand, the present invention also provides a calibration system for the spectral width of frequency-modulated laser pulses based on ergodic correlation. The system is composed of modular units corresponding to the method steps of the calibration method for the spectral width of frequency-modulated laser pulses based on ergodic correlation, for calibrating the spectral width of discrete comb-shaped frequency-modulated lasers.

[0009] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0010] This invention provides a calibration method and system for frequency-modulated laser pulse comb spectra based on a correlation ergodic algorithm. By establishing a correlation between the measured spectrum at medium precision and the theoretically simulated spectrum, the calibrated spectral width reflects the physical nature of phase modulation more accurately than the -3dB spectral width. Furthermore, the data obtained by this calibration method and system exhibits strong correlation (R>0.9), high linearity, and high confidence, making the data more reliable. Secondly, the calibration method and system provided by this invention can complete the spectral width calibration using only a high-precision spectrometer once. In subsequent frequent spectral measurements, accurate spectral widths can be obtained by measuring the spectrum with a common medium-precision spectrometer and examining the relationship curve between the measured and calibrated spectral widths. This calibration method and system reduce the frequency of using high-precision spectrometers, lower operating costs, and reduce reliance on high-end instruments, thus possessing significant economic value. Attached Figure Description

[0011] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0012] Figure 1 This is a schematic diagram of the laser device structure used in the embodiments of the present invention;

[0013] Figure 2 This is a flowchart of the calibration method provided by the present invention;

[0014] Figure 3 These are spectral data corresponding to different spectral widths in embodiments of the present invention, wherein Figure 3 (a) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.1 nm;

[0015] Figure 3 (b) is a comparison of the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.1 nm;

[0016] Figure 3 (c) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.2 nm;

[0017] Figure 3 (d) is a comparison graph of the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.2 nm;

[0018] Figure 3 (e) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.3 nm;

[0019] Figure 3 (f) is a comparison graph of the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.3 nm;

[0020] Figure 4 This is the relationship curve between the measured spectral width and the calibrated spectral width provided by the present invention.

[0021] In the attached diagram: 1-Laser seed source, 2-Phase modulator, 3-RF source, 4-Transmission amplification link, 5-Optical splitter, 6-Spectrometer. Detailed Implementation

[0022] All features disclosed in this specification, or steps in all methods or processes disclosed herein, may be combined in any way, except for mutually exclusive features and / or steps.

[0023] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0024] Example 1

[0025] This embodiment discloses a laser detection device for calibrating the spectral width of frequency-modulated laser pulses, such as... Figure 1 As shown, the device includes a laser seed source 1, a phase modulator 2, an radio frequency (RF) source 3, a transmission amplification link 4, a beam splitter 5, and a spectrometer 6, all positioned along the optical path. The laser seed source 1 provides a single-mode laser, and the RF source 3 provides multiple sets of RF source signals with different amplitudes. The phase modulator 2 modulates the laser phase based on the RF source signals. The laser transmission amplification link 4 transmits the modulated frequency-modulated laser pulses. The beam splitter 5 divides the laser into two parts; the main part continues to be transmitted, while the other part is sampled and measured by the spectrometer 6.

[0026] Example 2

[0027] This embodiment discloses a method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation. In a preferred embodiment, the calibration method can be performed using the laser device described in the previous embodiments. Figure 2 As shown, the frequency-modulated laser pulse spectral width calibration method includes the following steps:

[0028] Step S1: Load a series of radio frequency source signals with different amplitudes, and use a medium-precision measurement spectrometer and a high-precision measurement spectrometer to measure the frequency-modulated laser pulses under different radio frequency amplitude conditions to obtain measurement data such as the measurement spectral width, spectral morphology and point spread function.

[0029] In this embodiment, the laser seed source 1 emits a single-longitudinal-mode laser, the spectral distribution of which can be approximated as a delta function. Simultaneously, the radio frequency (RF) source 3 provides multiple sets of RF source signals with different amplitudes to the phase modulator 2. After being processed by the phase modulator 2, the single-longitudinal-mode laser becomes a frequency-modulated (FM) laser, and the spectral distribution of the FM laser is a discrete comb-shaped spectrum with left-right symmetry. The spacing of this discrete comb-shaped spectrum is determined by the RF modulation frequency, and the spectral width is determined by the amplitude of the applied RF source signal; the higher the amplitude of the RF source signal, the wider the FM spectrum. When the FM laser pulse is transmitted in the subsequent laser transmission amplification link 4, it will be affected by the non-uniform spectral transmittance, causing the spectral shape to change and no longer exhibit a completely symmetrical distribution.

[0030] In a preferred embodiment, the phase modulator 2 is a LiNbO3 waveguide phase modulator. A radio frequency source signal with a modulation frequency of 2.5 GHz is loaded onto the phase modulator 2, and the frequency modulation amplitude changes from 0V to 5V. Within this radio frequency amplitude range, the frequency modulation spectrum can be broadened to a maximum of 1 nm.

[0031] Under the same radio frequency amplitude modulation, measurements were performed using both a high-precision and a medium-precision spectrometer, and the corresponding measurement data were obtained. The high-precision spectrometer has a higher spectral resolution than the medium-precision spectrometer, and can measure the detailed spectral morphology of the frequency-modulated laser pulse. However, the high-precision spectrometer has the disadvantage of high operating cost, and its measurement accuracy decreases after repeated use. The medium-precision spectrometer, due to its limited resolution, can only obtain the spectral envelope and spectral width of the frequency-modulated laser pulse, but its operating cost is lower than that of the high-precision spectrometer. In this embodiment, the spectral resolution of the high-precision spectrometer is approximately 2 pm, and the spectral resolution of the medium-precision spectrometer is approximately 20 pm.

[0032] When the output amplitude of the RF source is 0 (i.e., the RF source output is off and there is no phase modulation), the spectrum measured by the high-precision spectrometer is the convolution of the single-longitudinal-mode laser spectral width and the spectral resolution of the high-precision spectrometer. Since the spectrum of the single-longitudinal-mode laser seed source is extremely narrow, much smaller than 1 pm, the spectral morphology obtained by the high-precision spectrometer when the RF source output amplitude is 0 can be regarded as the point spread function determined by the high-precision spectrometer.

[0033] Step S2: Assign initial laser parameters in the simulation program based on experimental parameters, and define the maximum spectral width and spectral step size to be traversed.

[0034] In a preferred embodiment, the experimental parameters include at least: a laser wavelength of 1053 nm, a frequency modulation frequency of 2.5 GHz, and a modulation depth, with a maximum modulation depth of 18, corresponding to a frequency-modulated laser spectral width of 0.32 nm. The initial laser parameters include laser wavelength, initial phase of RF modulation, RF modulation frequency, and modulation depth (determined by the RF amplitude). The maximum spectral width is the maximum traversal range for subsequent correlation traversal calculations. To ensure that the actual spectrum can be used for actual traversal calculations, the maximum spectral width should be greater than the actual spectral width. In a preferred experiment, the spectral width range measured by a medium-precision spectrometer is [0.03 nm, 0.32 nm], therefore, the maximum spectral width to be traversed is defined as 0.4 nm in the simulation program. The spectral step size should be as fine as possible; in this embodiment, the preferred spectral step size parameter is 0.0008 nm.

[0035] Step S3: Read a series of measurement data such as spectral morphology, spectral width and point spread function measured by the spectrometer, determine the effective spectral range and extract the effective spectral data from the measurement data;

[0036] In this embodiment, a spectral boundary threshold is preset. The measurement data within this threshold is considered valid spectral data, thus retaining the valid data and removing a series of zero values ​​and noise values ​​outside the valid data. After extracting the valid spectral data, the data can be normalized to obtain processed valid spectral data for correlation traversal calculation. In a preferred embodiment, the spectral boundary threshold is set to 0.001 of the maximum spectral value.

[0037] Step S4: Determine whether to perform spectral correlation traversal calculation. If so, execute the following correlation calculation steps in sequence:

[0038] The theoretical simulation spectra corresponding to different spectral widths within the traversal range are obtained through numerical calculation; in the preferred embodiment, the theoretical simulation spectra corresponding to all spectral widths to be traversed with a spectral traversal range of [0.03nm, 0.4nm] and a spectral step size of 0.0008nm are calculated respectively.

[0039] Multiple theoretical simulation spectra are convolved and filtered with point spread functions truncated within the effective spectral range to obtain the simulated spectra;

[0040] Align simulated spectral data and effective measured spectral data, wherein the effective measured spectral data is morphologically characteristic effective measured spectral data intercepted within the effective spectral range by a high-precision measuring spectrometer. ； In a preferred embodiment, the alignment is achieved by aligning the wavelength parameters of the horizontal axis.

[0041] The correlation between the simulated spectral data and the effective measured spectral data is calculated, and the corresponding calculation results are recorded.

[0042] Based on the initial laser parameter values ​​assigned in step S2, a series of theoretical simulation spectra corresponding to different measured spectral widths can be calculated and obtained. These theoretical simulation spectra are then convolved and filtered with the point spread function to obtain the simulated spectra. The simulated spectra represent theoretical simulation spectra considering the point spread function response characteristics of the high-precision spectrometer, and are morphologically closer to the measured spectra measured by the high-precision spectrometer. Next, using the effective measured spectral data as a reference, the simulated spectra within the effective measurement range are extracted. Interpolation sampling is used to unify and align the lengths of the measured and simulated spectral data. Finally, correlation calculations are performed between the aligned simulated spectra and the effective measured spectra, and the correlation values ​​are recorded.

[0043] Step S5: Determine if the spectral correlation traversal calculation loop has ended. If the loop has not ended, repeat step S4 for calculation; if the spectral correlation traversal calculation is no longer performed, the traversal loop ends. After the loop ends, compare all the correlation calculation values ​​to obtain the maximum correlation calculation value and the best matching spectral width corresponding to the maximum correlation calculation value.

[0044] In one embodiment, the decision to end the loop is based on a comparison between the maximum spectral width and the calculated spectral width value of the current traversal loop. The correlation traversal calculation ends when the calculated spectral width value is greater than or equal to the maximum spectral width. At this point, the entire loop traversal calculation has been completed according to steps S4-S5, yielding a series of correlation calculation values ​​between simulated spectral data and measured spectral data. By comparing these correlation calculation values, the largest correlation calculation value and the corresponding simulated spectral width are identified as the optimal matching spectral width. The optimal matching simulated spectrum can then be determined based on this optimal matching spectral width.

[0045] like Figure 3 As shown, Figure 3 In (b), (d), and (f), the black lines represent the best-matched simulated spectra, and the gray lines represent the measured spectra.

[0046] Specifically Figure 3 (a) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.1 nm. Figure 3 (b) is a comparison between the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.1 nm. As can be seen from the figure, when the laser pulse measurement spectral width is 0.1 nm, the maximum correlation value is 0.96723, and the corresponding theoretical simulated spectral width is 0.084941 nm. Figure 3 In (b), the black line represents the best-matched simulated spectrum, and the gray line represents the measured spectrum. It can be seen that the measured spectrum and the best-matched spectrum approximately overlap, with good spectral morphology and similar spectral width. Therefore, the calculated best-matched spectral data and the measured spectral data have good consistency and high confidence.

[0047] Figure 3 (c) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.2 nm. Figure 3 (d) is a comparison between the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.2 nm. The figure shows that when the laser pulse measurement spectral width is 0.2 nm, the maximum correlation value is 0.95906, and the corresponding theoretical simulated spectral width is 0.18894 nm. It can be seen that the calculated best-matched spectral data and the measured spectral data have good agreement and high confidence.

[0048] Figure 3 (e) is the spectral correlation ergodic curve corresponding to a laser pulse measurement spectral width of 0.3 nm. Figure 3 (f) is a comparison between the measured spectrum and the best-matched simulated spectrum when the laser pulse measurement spectral width is 0.3 nm. The figure shows that when the laser pulse measurement spectral width is 0.3 nm, the maximum correlation value is 0.91539, and the corresponding theoretical simulated spectral width is 0.28988 nm. It can be seen that the calculated best-matched spectral data and the measured spectral data have good agreement and high confidence.

[0049] Step S6: Repeat steps S3 to S5 to obtain the maximum correlation calculation value and the best matching spectral width corresponding to the maximum correlation calculation value, thereby fitting and plotting the first relationship curve characterizing the relationship between the spectral width measured by the measuring spectrometer and the calibrated spectral width.

[0050] In a preferred embodiment, correlation ergodic calculations were performed for the measured spectral widths of 0.05 nm, 0.1 nm, 0.125 nm, 0.18 nm, 0.2 nm, 0.25 nm, and 0.3 nm, respectively. After obtaining all the correlation ergodic calculation results, a linear fit was performed between the measured spectrum and the optimal matching spectral width. Based on all the acquired data, a first relationship curve characterizing the relationship between all measured spectral widths determined by the medium-precision measuring spectrometer and the calibrated spectral width can be plotted, such as... Figure 4As shown in the figure, the horizontal axis represents the measured spectral width determined by a medium-precision spectrometer, the left axis represents the calculated spectral width, the black dots represent the actual measured calibration data, the black line represents the fitted line, and the right axis represents the calculated correlation coefficients. The black squares represent the calculated correlation values ​​corresponding to the spectral data. The figure shows that the correlation values ​​for all data points are greater than 0.9, indicating a strong correlation. After linear fitting, the coefficient of determination R-squared (R²) is 0.9989, indicating that the correlation of this relationship curve is very high, and the confidence level is also very high.

[0051] Step S7: Perform a measurement on the spectrum to be measured using a medium-precision measuring spectrometer to obtain the measurement spectral width to be corrected, and determine the calibration spectral width corresponding to the measurement spectral width to be corrected from the first relationship curve, and use the calibration spectral width as the corrected spectral width of the spectrum to be measured.

[0052] After determining the first relationship curve between the spectral width measured by the measuring spectrometer and the calibrated spectral width according to the aforementioned steps of this invention, for each subsequent spectrum to be measured, a medium-precision measuring spectrometer can be used to measure the spectrum to be measured once, without using a high-precision measuring spectrometer, to obtain the measured spectral width to be corrected. Then, the calibrated spectral width corresponding to the measured spectral width to be corrected is determined from the first relationship curve, and this calibrated spectral width is used as the corrected spectral width of the spectrum to be measured, replacing the measured spectral width obtained by the medium-precision measuring instrument. This achieves more accurate spectral width correction and calibration of the spectrum to be measured.

[0053] The frequency-modulated laser pulse comb spectrum calibration method based on correlation ergodic method provided in this invention establishes a connection between medium-precision measured spectrum and theoretical simulation spectrum. The spectral width calibrated using measurement data from a high-precision spectrometer reflects the physical nature of phase modulation more accurately than the -3dB spectral width. Furthermore, the data obtained by this calibration method has strong correlation (R>0.9), high linearity, and high confidence, making the data more reliable.

[0054] Example 3

[0055] This embodiment provides a frequency-modulated laser pulse spectral width calibration system based on ergodic correlation, corresponding to any of the aforementioned method embodiments. The system consists of multiple module units for implementing the steps in the aforementioned method embodiments, and these module units cooperate to complete the aforementioned frequency-modulated laser pulse spectral width calibration method based on ergodic correlation.

[0056] Thus, the calibration method and system provided by this invention allow for the calibration of the spectral width using only a high-precision spectrometer once. Subsequent spectral measurements can then be performed using a standard medium-precision spectrometer, and the relationship curve between the measured and calibrated spectral widths can be found to obtain a more accurate spectral width. The calibration method and system provided by this invention reduce the frequency of using a high-precision spectrometer when measuring laser spectra, lowering operating costs and reducing reliance on high-end instruments, thus possessing significant economic value.

[0057] The present invention has been described in detail above. However, the present invention is not limited to the specific embodiments described above, nor to the application scenarios described above. It can be applied to any laser signal application scenario, and the present invention does not limit it in this regard. Furthermore, the present invention extends to any new features or any new combinations disclosed in this specification, as well as any new steps or any new combinations of any disclosed new methods or processes.

Claims

1. A method for calibrating the spectral width of frequency-modulated laser pulses based on ergodic correlation, used to calibrate the spectral width of discrete comb-shaped frequency-modulated lasers, characterized in that, The method includes: Step S1: Use a first measurement spectrometer and a second measurement spectrometer to perform a measurement on a series of frequency-modulated laser pulses under different radio frequency amplitude conditions, and obtain measurement data. The measurement data includes at least the measurement spectral width, spectral morphology, and point spread function. Step S2: Assign initial laser parameters and define the maximum spectral width and spectral step size to be traversed; Step S3: Read the measurement data, determine the effective spectral range, and extract the effective spectral data from the measurement data; Step S4: Determine whether to perform spectral correlation traversal calculation. If spectral correlation traversal calculation is performed, execute the correlation traversal calculation operation sequentially and obtain the correlation calculation result. The correlation traversal calculation operation includes: obtaining the theoretical simulation spectrum corresponding to different spectral widths through numerical calculation; convolving and filtering multiple theoretical simulation spectra with point spread functions to obtain the simulated spectrum; aligning the simulated spectral data and the effective measured spectral data, and performing correlation calculation between the simulated spectrum and the effective measured spectrum. Step S5: Determine whether the spectral correlation traversal calculation loop has ended. If the loop has not ended, repeat step S4. If the loop has ended, the correlation traversal calculation ends. Determine the maximum correlation calculation value and the best matching spectral width corresponding to the maximum correlation calculation value from all correlation traversal calculation results. Step S6: Repeat steps S3 to S5 to obtain the maximum correlation calculation value and the optimal matching spectral width corresponding to the maximum correlation calculation value. Determine the first relationship curve characterizing the relationship between the measured spectral width and the calibrated spectral width based on the optimal matching spectral width.

2. The method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1, characterized in that, The calibration method further includes step S7: performing a measurement on the spectrum to be measured using a first measuring spectrometer to obtain the measurement spectral width to be corrected, determining the calibration spectral width corresponding to the measurement spectral width to be corrected from the first relationship curve, and using the calibration spectral width as the corrected spectral width of the spectrum to be measured.

3. The method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1 or 2, characterized in that, In step S1, the first measuring spectrometer is a medium-precision measuring spectrometer or a low-precision measuring spectrometer, and the second measuring spectrometer is a high-precision measuring spectrometer or a medium-precision measuring spectrometer.

4. A method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1 or 2, characterized in that, The measurement data obtained by the first measuring spectrometer includes at least the spectral width, and the measurement data obtained by the second measuring spectrometer includes at least the spectral morphology and the point spread function.

5. The method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 4, characterized in that, The point spread function is the spectral morphology measured by a second measuring spectrometer when the radio frequency amplitude is 0.

6. A method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1 or 2, characterized in that, The initial laser parameters include at least the laser wavelength, the initial phase of the radio frequency modulation, the radio frequency modulation frequency, and the modulation depth.

7. A method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1 or 2, characterized in that, The maximum spectral width is the maximum traversal range during correlation traversal calculation, and the maximum spectral width is greater than the actual spectral width.

8. A method for calibrating the spectral width of a frequency-modulated laser pulse based on ergodic correlation as described in claim 1 or 2, characterized in that, The first relationship curve between the measured spectral width and the calibrated spectral width is plotted in step S6 by linearly fitting the measured spectrum and the theoretical simulation spectrum after obtaining all correlation traversal calculation results.

9. A frequency-modulated laser pulse spectral width calibration system based on ergodic correlation, characterized in that, The system is a system composed of module units corresponding to the method steps of any of the ergodic correlation-based frequency-modulated laser pulse spectral width calibration methods in claims 1-8, for calibrating the spectral width of discrete comb-shaped frequency-modulated lasers.

Images