Method and system for correcting spectral curvature of a planar grating spectrometer

Abstract

The application provides a plane grating spectrometer spectrum bending correction method and system, comprising the following steps: S1, adjusting the focal length of a condensing system and a focusing collimating system of the plane grating spectrometer to be the same, and setting the magnification of the plane grating spectrometer to be 1; S2, setting the incident slit and the exit slit of the focusing collimating system to be equal in height and width; S3, calculating the ratio of the focal length of the focusing collimating system to the height of the incident slit; S4, according to the obtained ratio, calculating the correction coefficient of the relationship between the exit wavelength of the slit with different proportional heights and the central wavelength of the slit, and the correction coefficient of the exit wavelength of the slit with different proportional heights; and S5, according to the coefficients, performing the pixel-by-pixel spectrum bending correction of the spectrometer in cooperation with the number of pixels of an optical receiving detector. The application can improve the final calibration accuracy of the spectrometer.

Description

Technical Field

[0001] This invention relates to the field of grating spectrometer technology, and more specifically, to a method and system for spectral curvature correction of a planar grating spectrometer. Background Technology

[0002] Grating spectrometers utilize various types of detectors to measure each spectral channel. To enhance the application value of spectrometer data, precise radiometric and spectral calibrations are necessary before use. The main techniques used in existing spectrometer calibration processes include: obtaining the spectral response function and bandwidth from the monochromator's collimated monochromator for spectral correction; and creating a responsivity calibration coefficient matrix for each detector pixel, followed by high-precision radiometric calibration through parameter modification. In monochromator spectral and radiometric calibration, the center wavelength accuracy and spectral bandwidth of each channel are the primary factors affecting calibration accuracy. Grating spectroscopic theory indicates that the slit width of the monochromator affects the bandwidth; however, when the slit width is less than 100 μm, we can consider the increment of the emitted light wavelength from the edge of the slit width to be linearly related to the width increment, which can be accurately represented by the output center wavelength at the slit center. Simultaneously, the length of the monochromator's entrance slit causes spectral line curvature, thus affecting the output spectral position and energy distribution at the exit slit.

[0003] Traditional grating spectral line bending correction methods rely on conventional analytical formulas, the derivation of which requires multiple approximations, resulting in complex overall expressions. Analysis of actual spectrometers using these formulas reveals that spectral line bending significantly impacts the final calibration results of detector pixel responsivity. Actual spectral measurement data shows that deviations in the visible light band can reach 20 nm, with clearly visible spectral line bending. To eliminate the influence of spectral lines on spectrometer calibration, current methods commonly employ multi-structure optical designs such as prism gratings or spectral correction of the final detector pixel calibration coefficients. The former method can reduce the magnitude of spectral line bending to some extent, but the complex structure limits subsequent correction accuracy. The second method is clearly suitable for the calibration of detector-based spectrometers, but its accuracy is limited by the complexity and approximation of the spectral line bending analysis equation, preventing effective improvement.

[0004] In practical applications of planar grating spectrometers, due to the presence of slit height, light incident from the edge of the entrance slit, after collimation, will illuminate the grating at a certain angle to the principal section. The corresponding diffraction angle will cause the outgoing light to deviate from the principal section, resulting in spectral line bending. Spectral line bending primarily affects the output spectral bandwidth of the spectrometer or monochromator, ultimately impacting the accuracy of spectral calibration. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and system for spectral bending correction in a planar grating spectrometer.

[0006] According to the present invention, a method and system for correcting spectral curvature in a planar grating spectrometer are provided, the solution of which is as follows:

[0007] In a first aspect, a method for spectral curvature correction in a planar grating spectrometer is provided, the method comprising:

[0008] Step S1: Adjust the focal lengths of the focusing system and the collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1;

[0009] Step S2: Set the entrance slit and exit slit of the focusing and collimating system to have the same height and width;

[0010] Step S3: Calculate and obtain the ratio of the focal length of the focusing and collimating system to the height of the entrance slit;

[0011] Step S4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the wavelength of the emitted light at different proportions of the slit height and the wavelength of the center of the slit, as well as the correction coefficient for the wavelength of the emitted light at different proportions of the slit height.

[0012] Step S5: Based on the various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

[0013] Preferably, step S1 includes:

[0014] Step S1.1: Using reflection imaging or projection imaging methods, set the focal length of the planar grating pre-focusing collimation system to f, and incident the planar grating with parallel light.

[0015] Step S1.2: Using reflection imaging or projection imaging methods, set the focal length of the planar grating post-focusing collimation system to f', so that f' = f, and receive the parallel light emitted from the planar grating.

[0016] Preferably, step S2 includes:

[0017] Step S2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h;

[0018] Step S2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

[0019] Preferably, step S3 includes: measuring the focal length f of the planar grating pre-focusing collimation system and the entrance slit height h, and calculating the ratio k = h / f.

[0020] Preferably, in step S4, calculating the correction coefficient for the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit includes:

[0021] Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained:

[0022]

[0023] The calculation of the wavelength correction coefficient for different proportions of slit height includes:

[0024] Calculate and obtain the emission wavelength λ' at the edge of the emission slit:

[0025]

[0026] The correction factor is:

[0027]

[0028] Preferably, step S5 includes:

[0029] Step S5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is then:

[0030]

[0031] Step S5.2: Using the correction coefficient Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

[0032] Secondly, a spectral curvature correction system for a planar grating spectrometer is provided, the system comprising:

[0033] Module M1: Adjust the focal lengths of the focusing system and collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1;

[0034] Module M2: Sets the entrance and exit slits of the focusing and collimating system to have the same height and width;

[0035] Module M3: Calculates the ratio of the focal length of the focusing and collimating system to the height of the entrance slit;

[0036] Module M4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit, as well as the correction coefficient for the emitted wavelength at different proportions of the slit height;

[0037] Module M5: Based on various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

[0038] Preferably, the module M1 includes:

[0039] Module M1.1: Using reflection imaging or projection imaging methods, the focal length of the pre-focusing collimation system of the planar grating is set to f, and the light is incident on the planar grating in the form of parallel light.

[0040] Module M1.2: Using reflection imaging or projection imaging methods, the focal length of the planar grating post-focusing collimation system is set to f', so that f' = f, to receive the parallel light emitted from the planar grating.

[0041] Preferably, the module M2 includes:

[0042] Module M2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h;

[0043] Module M2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

[0044] Preferably, the module M3 includes: measuring the focal length f of the planar grating pre-focusing collimation system and the entrance slit height h, and calculating the ratio k = h / f;

[0045] In module M4, the correction coefficients for calculating the relationship between the emitted wavelength at different proportions of slit height and the center wavelength of the slit include:

[0046] Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained:

[0047]

[0048] The calculation of the wavelength correction coefficient for different proportions of slit height includes:

[0049] Calculate and obtain the emission wavelength at the edge of the emission slit:

[0050]

[0051] The correction factor is:

[0052]

[0053] The module M5 includes:

[0054] Module M5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is:

[0055]

[0056] Module M5.2: Using correction coefficients Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The present invention provides a method for correcting output bandwidth variations in plane grating spectrometers caused by spectral curvature. This method avoids approximate substitution derivations, resulting in a simpler and more accurate approach, thereby improving the final calibration accuracy of the spectrometer. This method has significant economic and practical value for multiple applications of plane grating spectrometers.

[0059] Other beneficial effects of the present invention will be explained in detail through the introduction of specific technical features and technical solutions in specific embodiments. Those skilled in the art should be able to understand the beneficial technical effects brought about by these technical features and technical solutions through the introduction of these technical features and technical solutions. Attached Figure Description

[0060] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0061] Figure 1 This is a schematic diagram of the overall process of the present invention. Detailed Implementation

[0062] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0063] This invention provides a method for spectral curvature correction in a planar grating spectrometer, referring to... Figure 1 As shown, the method specifically includes the following:

[0064] Step S1: Adjust the focal lengths of the focusing system and the collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1.

[0065] Step S1 specifically includes:

[0066] Step S1.1: Set the focal length of the planar grating pre-focusing collimation system to f, and incident the planar grating with parallel light;

[0067] Step S1.2: Set the focal length of the planar grating post-focusing collimation system to f', so that f' = f, and receive the parallel light emitted from the planar grating.

[0068] Step S2: Set the entrance slit and exit slit of the focusing and collimating system to have the same height and width.

[0069] Step S2 specifically includes:

[0070] Step S2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h;

[0071] Step S2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

[0072] Step S3: Calculate the ratio of the focal length of the focusing and collimating system to the height of the entrance slit.

[0073] Specifically, the focal length f and the entrance slit height h of the planar grating pre-focusing collimation system are measured, and the ratio k = h / f is calculated.

[0074] Step S4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the wavelength emitted from the slit at different proportional heights and the wavelength at the center of the slit, as well as the correction coefficient for the wavelength emitted from the slit at different proportional heights.

[0075] The correction coefficients used to calculate the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit include:

[0076] Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained:

[0077]

[0078] The calculation of the wavelength correction factor for different proportions of slit height includes:

[0079] Calculate and obtain the emission wavelength at the edge of the emission slit:

[0080]

[0081] The correction factor is:

[0082]

[0083] Step S5: Based on the various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

[0084] Step S5 specifically includes:

[0085] Step S5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is then:

[0086]

[0087] Step S5.2: Using the correction coefficient Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

[0088] This invention also provides a spectral curvature correction system for a planar grating spectrometer. This system can be implemented by executing the steps of the planar grating spectrometer spectral curvature correction method. That is, those skilled in the art can understand the planar grating spectrometer spectral curvature correction method as a preferred embodiment of the planar grating spectrometer spectral curvature correction system. The system specifically includes the following:

[0089] Module M1: Adjust the focal length of the focusing system and the collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1.

[0090] Module M1 specifically includes:

[0091] Module M1.1: Using reflection imaging or projection imaging methods, the focal length of the pre-focusing collimation system of the planar grating is set to f, and the light is incident on the planar grating in the form of parallel light.

[0092] Module M1.2: Using reflection imaging or projection imaging methods, the focal length of the planar grating post-focusing collimation system is set to f', so that f' = f, to receive the parallel light emitted from the planar grating.

[0093] Module M2: Sets the entrance and exit slits of the focusing and collimating system to have the same height and width.

[0094] Module M2 specifically includes:

[0095] Module M2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h;

[0096] Module M2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

[0097] Module M3: Calculates the ratio of the focal length of the focusing and collimating system to the height of the entrance slit.

[0098] Specifically, the focal length f and the entrance slit height h of the planar grating pre-focusing collimation system are measured, and the ratio k = h / f is calculated.

[0099] Module M4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the wavelength of the emitted light at different proportions of the slit height and the wavelength of the center of the slit, as well as the correction coefficient for the wavelength of the emitted light at different proportions of the slit height.

[0100] The correction coefficients used to calculate the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit include:

[0101] Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained:

[0102]

[0103] The calculation of the wavelength correction factor for different proportions of slit height includes:

[0104] Calculate and obtain the emission wavelength at the edge of the emission slit:

[0105]

[0106] The correction factor is:

[0107]

[0108] Module M5: Based on various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

[0109] The M5 module specifically includes:

[0110] Module M5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is:

[0111]

[0112] Module M5.2: Using correction coefficients Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

[0113] Next, the invention will be described in more detail through specific practical operations.

[0114] This invention provides a high-precision planar grating spectrometer spectral curvature correction method, such as... Figure 1 As shown, it includes the following steps:

[0115] Step 1: Design the focal length of the focusing system and collimation system of the plane grating spectrometer to be the same, and keep the magnification of the spectrometer system to 1.

[0116] Step 1.1: Using reflection imaging or projection imaging methods, design a planar grating pre-focusing collimation system with a focal length of f = 100 mm, so that the light is incident on the planar grating in the form of parallel light.

[0117] Step 1.2: Using reflection imaging or projection imaging methods, design a planar grating post-focusing collimation system with a focal length of f', such that f' = f = 100mm, to receive the parallel light emitted from the planar grating.

[0118] Step 2: Design the entrance slit and exit slit to have the same height and width, and determine the ratio of the focal length of the grating spectrometer to the height of the entrance slit.

[0119] Step 2.1: The entrance slit of the planar grating pre-focusing collimation system described in the above scheme is used as the entrance slit of the overall grating spectrometer system, and the height of the entrance slit is designed to be 2h = 20mm.

[0120] Step 2.2: The exit slit of the planar grating post-focusing collimation system described in the above scheme is used as the exit slit of the overall grating spectrometer system, ensuring that the exit slit height 2h' = 2h = 20mm.

[0121] Step 2.3: Measure the focal length f and the entrance slit height h of the planar grating pre-focusing collimation system described in the above scheme, and calculate the ratio k = h / f = 0.1.

[0122] Step 3: Accurately calculate the correction coefficients for the relationship between the wavelength emitted from the slit at different proportions of height and the wavelength at the center of the slit.

[0123] Step 3.1: Based on the above scheme, k = h / f = 0.1, the relationship between the emission wavelength offset Δλ at the edge of the emission slit and the slit center wavelength λ = 600 nm is obtained.

[0124] Step 3.2: Calculate the emission wavelength at the edge of the exit slit. The correction factor is

[0125]

[0126] Step 4: Perform pixel-by-pixel spectral curvature correction of the spectrometer in accordance with the number of pixels of the optical receiver detector.

[0127] Step 4.1: The number of detector pixels is set to 2l = 20. Starting from the center pixel of the detector, the correction coefficient for the spectral curvature of each pixel from n = 1 to n = 10, symmetrically arranged vertically, is: The per-pixel correction coefficients are shown in Table 1 below:

[0128] Table 1: Per-pixel correction coefficients

[0129]

[0130] Step 4.2: Using the pixel-by-pixel correction coefficient table described in the above scheme, perform spectral curvature correction on the column detector pixel by pixel. According to the above scheme, when the slit center wavelength λ = 600nm, the corresponding output spectral wavelengths of each pixel are shown in Table 2 below:

[0131] Table 2: Output Spectral Wavelengths for Pixel-by-Pixel Correction

[0132]

[0133] To illustrate the practicality of the method in this invention, a prior art method is selected as a comparison method. The prior art generally uses the planar grating equation to calculate the diffraction polar angle θ of monochromatic light incident from the edge of a slit with a height of 2h, where the wavelength is the same as the center wavelength (λ0). m2 The angle θ of the light rays with wavelength λ0 at the center of the principal section m1 The angle difference Δθ is approximately,

[0134]

[0135] Where d is the grating constant, with the same unit as λ0; θ m2→1 Represents the diffraction polar angle θ m2 The emission angle Δθ, projected onto the principal section, is in radians. Based on the above formula, the relationship between the wavelength shift Δλ of the spectral wavelength received at the detector edge and the wavelength at the slit center can be derived as follows:

[0136]

[0137] The above analysis shows that when using traditional methods to correct the spectral curvature of a spectrometer output spectrum, design parameters such as grating constant, incident light angle, and grating order are required. At the same time, the calculation process uses a small number of approximations to simplify the conditions, and the accuracy of the derived calculation formula is lower than that of the method provided by this invention, which does not use approximations. Furthermore, due to the inclusion of complex forms such as trigonometric functions, the accuracy will continue to decrease when performing detector pixel-by-pixel correction.

[0138] The present invention provides a method for correcting output bandwidth variations in planar grating spectrometers caused by spectral curvature. This method avoids approximate substitution derivations, resulting in concise parameters and accurate calculations. It improves the pixel-level calibration accuracy of the spectrometer's output, while reducing the requirements for grating parameters and optical path incident design. This enhances the flexibility of spectrometer design upgrades and mitigates the limitations of output bandwidth correction. This method has significant economic and practical value for multiple applications of planar grating spectrometers.

[0139] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0140] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for spectral curvature correction in a planar grating spectrometer, characterized in that, include: Step S1: Adjust the focal lengths of the focusing system and the collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1; Step S2: Set the entrance slit and exit slit of the focusing and collimating system to have the same height and width; Step S3: Calculate and obtain the ratio of the focal length of the focusing and collimating system to the height of the entrance slit; Step S4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the wavelength of the emitted light at different proportions of the slit height and the wavelength of the center of the slit, as well as the correction coefficient for the wavelength of the emitted light at different proportions of the slit height. Step S5: Based on the various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

2. The spectral curvature correction method for a planar grating spectrometer according to claim 1, characterized in that, Step S1 includes: Step S1.1: Using reflection imaging or projection imaging methods, set the focal length of the planar grating pre-focusing collimation system to f, and incident the planar grating with parallel light. Step S1.2: Using reflection imaging or projection imaging methods, set the focal length of the planar grating post-focusing collimation system to f', so that f' = f, and receive the parallel light emitted from the planar grating.

3. The spectral curvature correction method for a planar grating spectrometer according to claim 1, characterized in that, Step S2 includes: Step S2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h; Step S2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

4. The spectral curvature correction method for a planar grating spectrometer according to claim 1, characterized in that, Step S3 includes: measuring the focal length f of the planar grating pre-focusing collimation system and the entrance slit height h, and calculating the ratio k = h / f.

5. The spectral curvature correction method for a planar grating spectrometer according to claim 4, characterized in that, In step S4, the calculation of the correction coefficient for the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit includes: Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained: The calculation of the wavelength correction coefficient for different proportions of slit height includes: Calculate and obtain the emission wavelength at the edge of the emission slit: The correction factor is:

6. The spectral curvature correction method for a planar grating spectrometer according to claim 4, characterized in that, Step S5 includes: Step S5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is then: Step S5.2: Using the correction coefficient Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

7. A spectral curvature correction system for a planar grating spectrometer, characterized in that, include: Module M1: Adjust the focal lengths of the focusing system and collimation system of the plane grating spectrometer to be the same, and set the magnification of the plane grating spectrometer to 1; Module M2: Sets the entrance and exit slits of the focusing and collimating system to have the same height and width; Module M3: Calculates the ratio of the focal length of the focusing and collimating system to the height of the entrance slit; Module M4: Based on the obtained ratio, calculate the correction coefficient for the relationship between the emitted wavelength at different proportions of the slit height and the center wavelength of the slit, as well as the correction coefficient for the emitted wavelength at different proportions of the slit height; Module M5: Based on various coefficients and the number of pixels of the optical receiver detector, perform pixel-by-pixel spectral curvature correction of the spectrometer.

8. The spectral curvature correction system for a planar grating spectrometer according to claim 7, characterized in that, The module M1 includes: Module M1.1: Using reflection imaging or projection imaging methods, the focal length of the pre-focusing collimation system of the planar grating is set to f, and the light is incident on the planar grating in the form of parallel light. Module M1.2: Using reflection imaging or projection imaging methods, the focal length of the planar grating post-focusing collimation system is set to f', so that f' = f, to receive the parallel light emitted from the planar grating.

9. The spectral curvature correction system for a planar grating spectrometer according to claim 7, characterized in that, The module M2 includes: Module M2.1: Use the entrance slit of the planar grating pre-focusing collimation system as the entrance slit of the overall grating spectrometer system, and set the entrance slit height to 2h; Module M2.2: Use the exit slit of the planar grating rear focusing and collimating system as the exit slit of the overall grating spectrometer system, and maintain the exit slit height 2h' = 2h.

10. The spectral curvature correction system for a planar grating spectrometer according to claim 7, characterized in that, The module M3 includes: measuring the focal length f of the planar grating pre-focusing collimation system and the entrance slit height h, and calculating the ratio k = h / f; In module M4, the correction coefficients for calculating the relationship between the emitted wavelength at different proportions of slit height and the center wavelength of the slit include: Based on the ratio k = h / f, the relationship between the wavelength offset Δλ at the edge of the exit slit and the wavelength λ at the center of the slit is obtained: The calculation of the wavelength correction coefficient for different proportions of slit height includes: Calculate and obtain the emission wavelength at the edge of the emission slit: The correction factor is: The module M5 includes: Module M5.1: The number of detector pixels is (2l+1), where the center pixel is numbered 0, and l represents the pixel number at the top and bottom symmetrical edges of the detector. The correction coefficient for the spectral curvature of the nth pixel at the top and bottom symmetrical edges is: Module M5.2: Using correction coefficients Perform spectral bending correction on a pixel-by-pixel basis for the array detector.

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