CN116755246A - Chromatic aberration correction method of high-resolution Roland round optical system - Google Patents

Abstract

The application discloses a chromatic aberration correction method of a high-resolution Roland round optical system, which comprises the following steps: based on a high-resolution Roland circle optical system, dividing the characteristic wavelength corresponding to each element into wave bands, and establishing a central wavelength for each wave band; acquiring the offset of each central wavelength, adding a diffraction optical path, and combining the diffraction angles to establish the relative positions of imaging points after the offset of each wavelength; setting a vertical weight for the characteristic wavelength of each wave band, and carrying out fitting optimization on the relative positions of the imaging points after the deviation of each wavelength is established to obtain the optimal position of the image plane; and acquiring the center offset distance and the offset inclination angle of the image plane in the high-resolution Rowland optical system through the optimal position of the image plane, and combining the high-resolution Rowland optical system to complete chromatic aberration correction. The application adopts an image plane design mode based on weighted least square chromatic aberration correction, solves the problem of aberration generated by defocusing when non-flat field focusing is converted into flat field focusing, and realizes high resolution.

Description

Chromatic aberration correction method of high-resolution Roland round optical system

Technical Field

The application belongs to the technical field of spectrometers, and particularly relates to a chromatic aberration correction method of a high-resolution Roland round optical system.

Background

Spectrometers are often used as detection tools in the field of practical industry for qualitative and quantitative analysis of some trace elements. Today, with the development of the steel industry, the chemical industry, the food industry, the mineral exploration industry, etc., the demand for spectrometers is also becoming enormous. For example, in the steel industry, there is a constant need for improvement in steel quality. Therefore, in the steel production process, a spectrum direct reading method is often used for detecting the content of trace elements in metal, so that the type of the measured metal and the quality of the metal are distinguished. Since it is often necessary to detect trace elements in very small amounts, the development of spectrometers to achieve high resolution has become important. Spectrometers, also known as spectrometers, are commonly referred to as direct-reading spectrometers, which are typically classified into Czerny-Turner type systems, rowland circle systems, and echelon systems, depending on the type of spectroscopic system. The rowland circle spectrometer has the advantages of full spectrum high resolution, high measurement precision and accuracy, simple light path and the like, and is often developed into other precise optical instruments by combining different light sources, such as: LIBS spectroscopy, spark direct-reading spectroscopy, ICP spectroscopy, and the like. The most important performance index in spectroscopic systems used in any precision instrument is resolution. A common approach to achieve higher resolution is to use a concave grating with a higher number of lines and a high radius of curvature, but high scale gratings tend to be relatively costly and larger radii of curvature also result in an excessively large volume design of the optical path. In addition, there are also common methods that use smaller width slits, which, although they increase the resolution of a portion of the system, can result in reduced light sensitivity of the overall system. It is also more difficult and costly to fabricate for high reticle density mechanically etched concave gratings, and can result in larger system aberrations and larger signal-to-noise ratios. For the application of the holographic concave grating, the defects of the common concave grating are well optimized. For the holographic concave grating, the holographic concave grating has no ghost lines, the stray light is extremely small, the diffraction efficiency of the grating is greatly improved compared with that of the common grating, and the application of the holographic technology can meet the requirement of high-density reticle, so that the dispersion rate and resolution of the holographic concave grating are also better improved. The optical system is a Roland circle optical system designed based on a holographic concave grating with 2400L/mm reticle density and a curvature radius of 401.56 mm. In order to meet the high resolution requirement in the analysis industry, the application designs a method for fitting chromatic aberration correction based on a weighted least square method, which well optimizes defocusing aberration generated by collecting final imaging of planar photosensitive surfaces of photoelectric sensors such as CMOS. In addition, the method for optimizing the defocusing aberration well solves the problem of larger defocusing aberration caused by the fact that final imaging points shift back and forth at the theoretical Rowland circle position in the condensing module due to different focal lengths of light with different characteristic wavelengths after the lens is focused.

Disclosure of Invention

In order to solve the technical problems, the application provides a chromatic aberration correction method of a high-resolution Roland circle optical system, which optimizes out-of-focus aberration generated by collecting final imaging of a plane photosensitive surface of a photoelectric sensor such as a CMOS.

In order to achieve the above object, the present application provides a chromatic aberration correction method of a high-resolution rochon optical system, comprising:

based on a high-resolution Roland circle optical system, dividing the characteristic wavelength corresponding to each element into wave bands, and establishing a central wavelength for each wave band;

acquiring the offset of each central wavelength, adding a diffraction optical path, and combining the diffraction angles to establish the relative positions of imaging points after the offset of each wavelength;

setting a vertical weight for the characteristic wavelength of each wave band, and carrying out fitting optimization on the relative positions of the imaging points after the deviation of each wavelength is established to obtain the optimal position of the image plane;

and acquiring the center offset distance and the offset inclination angle of the image plane in the high-resolution Rowland optical system through the optimal position of the image plane, and combining the high-resolution Rowland optical system to complete chromatic aberration correction.

Optionally, the high-resolution rowland circle optical system includes: the optical slit, the holographic concave grating and the seven photoelectric sensors are all positioned on the Rowland circle; the optical slit receives light focused by the plano-convex lens, the light is projected on the holographic concave grating to carry out dispersion in the meridian direction, and diffracted light of characteristic wavelengths corresponding to each element after dispersion is received by the seven paths of photoelectric sensors.

Optionally, the optical slit is a line slit, and the optical slit is parallel to the scribing direction of the holographic concave grating.

Optionally, the seven-path photoelectric sensor includes: the photoelectric sensor of the 1 st wave band, the photoelectric sensor of the 2 nd wave band, the photoelectric sensor of the 3 rd wave band, the photoelectric sensor of the 4 th wave band, the photoelectric sensor of the 5 th wave band, the photoelectric sensor of the 6 th wave band and the photoelectric sensor of the 7 th wave band.

Optionally, the method for dividing the characteristic wavelength corresponding to each element into the bands includes:

obtaining diffraction angles of each element characteristic wavelength, and arranging the diffraction angles in sequence;

setting a threshold span to divide the wave band, and dividing the wave band into seven sections to be received by the seven-path photoelectric sensor.

Optionally, the method for establishing a center wavelength for each band includes:

based on the divided wave bands, the diffraction angles of the maximum characteristic wavelength and the minimum characteristic wavelength in the wave bands are averaged, and a central wavelength is established by combining a grating equation to obtain each wave band.

Optionally, the method for obtaining the offset of each center wavelength includes:

wherein EFL (lambda) is the offset of each center wavelength, X is the thickness of the plano-convex lens, r ₁ The curvature radius of the plane convex lens curved surface is D, the clear aperture of the entrance hole is n ₁ For corresponding featuresWavelength lambda is in material CaF ₂ In (a) and M is an expression for the wavelength lambda, i ₁ Is the angle of incidence.

Optionally, setting a standing weight for a characteristic wavelength of each band, and performing fitting optimization on the relative positions of imaging points after each wavelength deviation is established, so as to obtain an optimal position of an image plane, wherein the method comprises the following steps:

introducing offset on the basis of the original imaging point to obtain the relative position of the imaging point after each wavelength is offset;

setting a vertical weight for characteristic wavelengths of each wave band, and carrying out weighted least square fitting optimization according to the duty ratio of each weight based on the relative positions of imaging points after each wavelength is deviated to obtain the optimal position of the image plane.

Optionally, the method for obtaining the center offset and the offset tilt angle of the image plane in the high-resolution rochon optical system includes:

wherein AB is the center offset distance, PBP' is the offset inclination angle, f is the curvature radius of the holographic concave grating, the angle theta_Cenλ is the diffraction angle of the center wavelength of each wave band, and k_Wei and b_Wei are the slope and intercept of projection of the sensor photosurface on the meridian plane after fitting by the weighted least square method.

The application has the technical effects that: the application discloses a chromatic aberration correction method of a high-resolution Roland round optical system, which adopts an image plane design mode based on weighted least square chromatic aberration correction, solves the problem of aberration generated by defocusing when non-flat field focusing is converted into flat field focusing, and realizes high resolution; meanwhile, as weights are set for the characteristic wavelengths in the wave bands, the resolution of the characteristic wavelengths in the wave bands can be adjusted through the weights.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

FIG. 1 is a schematic diagram of an optical system according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a plano-convex lens focusing optic according to an embodiment of the present application;

FIG. 3 is a graph of a weighted least squares fit result in accordance with an embodiment of the present application;

FIG. 4 is a dot column diagram of characteristic wavelengths of the 1 st band P, S, B, sb, as, sn and the C element of the embodiment of the application;

FIG. 5 is a plot of the meridian direction imaging width variation of the final imaged point of the embodiment of the present application at 175-200 nm (a), 200-400 nm (b) bands;

FIG. 6 is a spectrum diagram of 175-200 nm on a linear array CMOS according to an embodiment of the present application;

FIG. 7 is a spectrum diagram of 200-400 nm on a linear array CMOS according to an embodiment of the present application;

FIG. 8 is a flow chart of a chromatic aberration correction method for a high resolution Roland circle optical system according to an embodiment of the application; wherein: 1 is a plano-convex lens; 2 is an optical slit; 3 is Rowland circle; 4 is a holographic concave grating; 5 is a photoelectric sensor of the 1 st section; 6 is a photoelectric sensor of the 2 nd section; 7 is a photoelectric sensor of the 3 rd section; 8 is a 4 th photoelectric sensor; 9 is a 5 th-stage photoelectric sensor; 10 is a photoelectric sensor of the 6 th section; 11 is the 7 th photoelectric sensor.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer executable instructions, and that although a logical order is illustrated in the flowcharts, in some cases the steps illustrated or described may be performed in an order other than that illustrated herein.

As shown in fig. 1, a chromatic aberration correction method of a high-resolution rowland circle optical system, wherein the optical system comprises a plano-convex lens 1, an optical slit 2, a rowland circle 3, a holographic concave grating 4, a 1 st segment photosensor 5, a 2 nd segment photosensor 6, a 3 rd segment photosensor 7, a 4 th segment photosensor 8, a 5 th segment photosensor 9, a 6 th segment photosensor 10, and a 7 th segment photosensor 11; wherein the optical slit 2, the holographic concave grating 4 and the theoretical optimal focus of the light rays with the characteristic wavelengths of the elements are all on the Roland circle 3.

The dispersion system provided by the application is suitable for 160 nm-500 nm of short wavelength, firstly, all element characteristic wavelengths are orderly sequenced from small to large, then diffraction angles are calculated by a grating formula, and the formula is as follows:

β＝arcSin(mλ10 ^-6 ·2400-Sin42°)

wherein, alpha is the grating incidence angle of 42 degrees, beta is the diffraction angle required, lambda is the characteristic wavelength of each element, m is the order of 1 used by the Roland round optical dispersion system provided by the application, and k is the grating constant of the holographic concave grating, namely the reciprocal 1/2400 of the grating line number.

The system of optical dispersion of the present application comprises a total of 7 bands, after which a series of diffraction angles are divided into bands with a span of 2 ° and then the respective bands are established. Wherein the 1 st band contains characteristic wavelengths of 7 elements in total of P, S, B, sb, as, sn and C, the 2 nd band contains characteristic wavelengths of 2 elements in total of Pb and Co, the 3 rd band contains characteristic wavelengths of 2 elements in total of Si and Cr, the 4 th band contains characteristic wavelengths of 2 elements in total of Mo and Mn, the 5 th band contains characteristic wavelengths of 3 elements in total of Bi, V and Nb, the 6 th band contains characteristic wavelengths of 3 elements in total of Cu, ti and Ni, and finally the 7 th band contains characteristic wavelengths of 3 elements in total of Ca, al and W.

After the classification of the wavelength bands is completed, a central wavelength needs to be set up for each wavelength band in order to realize flat field incidence, and the final imaging surface of the central wavelength is located at the centroid position of the photosensitive surface of the photoelectric sensor. And the resolution values of the individual characteristic wavelengths of each segment remain substantially symmetrical about the center wavelength, only the diffracted light of the center wavelength needs to be taken as the angular bisector of the angle between the maximum and minimum wavelength diffracted light of the segment to achieve this. Therefore, to determine the center wavelength of a certain band, the diffraction angle of the center wavelength of the band is first determined, and in order to achieve the above result, the diffraction angle must be the average value of the maximum and minimum diffraction angles of the band, and only a specific value of the center wavelength needs to be deduced through a diffraction equation after the diffraction angle of the center wavelength is obtained.

Since the plano-convex lens 1 focusing the parallel light emitted by the light source to the optical slit 2 is designed in front of the optical slit 2, the curvature radius of the plano-convex lens 1 is mainly optimized by the characteristic wavelength of each element in the 1 st wave band in the optical simulation software Zemax. But this also results in different focal lengths for different characteristic wavelengths, due to the different refractive indices of the different wavelengths in the same material. The starting point of the whole rowland circle optical system is at the center of the optical slit 2 located on the rowland circle. But due to the use of the plano-convex lens 1, it also results in that the focal points of the different characteristic wavelengths are not at the optical slit 2, but are distributed in sequence in front of and behind the optical slit 2. This also results in a certain amount of shift in the final imaging point for the different characteristic wavelengths in the overall dispersive system.

The shift of each element characteristic wavelength caused by the plano-convex lens 1 is then calculated by geometric optics, which is shown in fig. 2 as a focusing optical schematic diagram of the plano-convex lens 1 in the present system, and since the focal length of the plano-convex lens 1 is calculated next, fig. 2 only takes the upper half of the meridian projection of the plano-convex lens 1. Where the curved surface Ah is the front surface of the plano-convex lens 1 and CX is the rear surface. Since the clear aperture of the system of the present application is 10mm, the spot-to-center distance presented on the plano-convex lens 1 is D/2=5 mm. As shown in fig. 2, point a is the boundary point of the plano-convex lens spot. The incident angle i can be obtained by the following formula ₁ Is a value of (2). Wherein r is ₁ The radius of curvature of the plano-convex lens 1, as simulated in Zemax,

theta is shown in figure 2 ₁ Through the first refraction angle of the plano-convex lens. i.e ₂ Is the second incident angle of the rear surface of the plano-convex lens 1, θ ₂ Is the second refraction angle of the boundary light passing through the plano-convex lens 1. The focal lengths efl=ix+xl at which different characteristic wavelengths can be obtained are thus an equation for λ, see the following formula;

wherein X is a constant of 2.66mm, which is the thickness, r, of the plano-convex lens 1 ₁ The curvature radius of the curved surface of the plano-convex lens 1 is 53.62594mm, and D is the clear aperture of the entrance hole of 10mm. And wherein n is ₁ For the corresponding characteristic wavelength lambda in the material CaF ₂ The refractive index of (c) is calculated by the following Schott equation,

the offset EFL of each element characteristic wavelength in the diffraction direction can be calculated by the above formula as shown in table 1. The imaging points after the diffraction of each characteristic wavelength after the offset is generated are arranged according to the wavelength sequence to form an irregular curved surface, so the imaging points still belong to an optical system with non-flat field focusing at the moment, and in order to enable the imaging points to be finally collected by the photosensitive surface of the photoelectric sensor, the final imaging focus of each characteristic wavelength needs to be fitted. Because the importance degree of detection of each element is inconsistent in the actual analysis, the weighted least square method is finally used for fitting, and all the offset imaging points are re-fitted into a straight line, and the straight line is the projection of the photosurface on the meridian plane.

After the offset of each characteristic wavelength is obtained, the offset can be added on the basis of the original diffraction optical path to obtain an offset diffraction optical path, and the relative position of each wavelength can be basically determined through polar coordinates by combining the diffraction angles, and then the relative position is converted into rectangular coordinates by using the following formula.

Some basic parameters need to be obtained before using a weighted least squares fit. First, a weighted average of the abscissa of each offset imaging point is calculated using the following formula.

After the weighted average of the abscissas is calculated by the above formula, the deviation Δwei_x (λ) of each abscissas with respect to the weighted average can be calculated by the following formula _i ) And ΔWei_Y (lambda) _i )。

And finally, calculating the slope k_Wei and the intercept b_Wei after the weighted least square fitting by the following formula.

Taking band 1 as an example, using weighted least squares simulation in MATLAB, values of k_wei and b_wei are-1.2623 and 568.6207, respectively, and the fitted simulation lines are shown in fig. 3. The curve is the curve of the imaging point after the offset of each element before fitting, and the straight line is the straight line after fitting by using a weighted least square method. Obviously, compared with the common least square fitting, the weighted least square fitting can obviously greatly optimize the defocusing phenomenon of the characteristic wavelengths of the three elements P, S and C, so that the resolution of the three elements is greatly improved compared with other elements.

After the slope and intercept of the projection straight line of the photoelectric sensor image plane on the meridian plane are obtained, two parameters of a center offset AB and an offset inclination angle < PBP' are calculated through the following formula.

In the formula, f is the curvature radius of the holographic concave grating, the angle theta_Cenλ is the diffraction angle of the central wavelength of each wave band, and k_Wei and b_Wei are the slope and intercept of projection of the sensor photosurface on the meridian plane after the weighted least square method is fit. These two parameters will be the main parameters for optimizing defocus in the actual design process, simulation in Zemax.

Still taking the first band as an example, the final imaged point chart after correcting chromatic aberration is shown in fig. 4, which is a point chart of imaging of each element characteristic wavelength in the band in the respective band image planes. Since the holographic concave grating can only focus diffracted light on meridian plane, focusing effect in sagittal direction is poor. The diffraction direction of the characteristic wavelength is still along the meridian plane. The horizontal direction of the point chart corresponds to the sagittal direction in the optical path chart and the actual optical system of fig. 1, and the vertical direction of the point chart corresponds to the meridional direction of the optical path chart and the actual optical system, as shown in fig. 4. Since the width of the photosensitive surface of the photosensor is limited in the actual case, only the most middle part of the dot line diagram as shown in fig. 4 can be actually acquired. The width of the spot diagram in the transverse sagittal direction does not affect the performance of the optical system, while the imaging width of each characteristic wavelength in the longitudinal meridian direction is closely related to the performance result of the optical system.

FIG. 5 shows the variation of imaging width with wavelength in the meridian direction of the point map in the wavelength range of 175-200 nm and 200-400 nm. Where fig. 5 (a) is a plot of the change in the range of 175-200 nm, it will be appreciated from the preceding paragraphs that the wavelengths in this band are predominantly imaged onto the image plane in band 1. Since the three elements P, S and C are important in the actual detection case in this band range, the weighted least squares fit is used where the weights of the three elements are higher than the other elements. Therefore, the optimization of the defocus aberration of P, S and C elements can reach an optimal condition, and the three elements are distributed at two ends of the 1 st band. Therefore, as shown in fig. 5 (a), the curve of the imaging width of the point chart of the first band in the meridian direction shows a trend of small at both ends and large in the middle, wherein the imaging width of the three elements P, S and C in the meridian direction can be maintained substantially at around 7um, and the imaging width of the two elements B and Sb in the meridian direction in the vicinity of the center wavelength of the 1 st band can be maintained at around 16um although being large. The trend is also mainly caused by the fact that the effective area of the photosurface has a large application range because the wavelength of the characteristic elements contained in the 1 st wave band is large. The meridian imaging width in the 200 to 400nm band range as shown in fig. 5 (b) can be maintained substantially in the range of 7 to 9um, compared with the other six bands, without much fluctuation.

FIG. 6 is a full spectrum of a simulated Roland circle optical system on a CMOS photoelectric sensor in a wavelength range from 175 to 200nm in a 1 st band, and from the result of the spectrum, characteristic wavelengths of elements can be obviously separated from the characteristic wavelengths by 0.02nm, characteristic wavelengths of elements identified by a part of important resolution indexes in the graph are (178.283 nm, 178.303nm, 180.731nm, 180.751nm, 182.64nm, 182.66nm, 187.115nm, 187.135nm, 193.091nm and 193.111 nm), and the characteristic wavelengths can obtain distinguishable spectrum diagrams.

FIG. 7 is a full spectrum of a simulated Roland circle optical system on a CMOS photosensor in the wavelength range of 200-400 nm from 2-7 bands, the characteristic wavelengths of each element can be obviously separated from the characteristic wavelengths of the elements, which are separated from the characteristic wavelengths by 0.02nm, the characteristic wavelengths of the elements identified by important resolution indexes in the figure are (251.611nm 251.631nm, 267.7159nm, 267.736nm, 281.615nm, 281.635nm, 306.772nm, 306.792nm, 313.079nm, 313.099nm, 327.395nm, 327.415nm, 341.476nm, 341.496nm, 393.366n, 393.386nm, 400.8753nm and 400.895 nm), and the characteristic wavelengths can obtain distinguishable spectrograms.

According to the analysis of the results, the resolution of the characteristic wavelength corresponding to each element of the dispersion system provided by the application can be kept at 0.02nm, and the design requirement is obviously met.

The present application is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present application are intended to be included in the scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (9)

1. A chromatic aberration correction method of a high-resolution rowland circle optical system, comprising:

based on a high-resolution Roland circle optical system, dividing the characteristic wavelength corresponding to each element into wave bands, and establishing a central wavelength for each wave band;

acquiring the offset of each central wavelength, adding a diffraction optical path, and combining the diffraction angles to establish the relative positions of imaging points after the offset of each wavelength;

setting a vertical weight for the characteristic wavelength of each wave band, and carrying out fitting optimization on the relative positions of the imaging points after the deviation of each wavelength is established to obtain the optimal position of the image plane;

and acquiring the center offset distance and the offset inclination angle of the image plane in the high-resolution Rowland optical system through the optimal position of the image plane, and combining the high-resolution Rowland optical system to complete chromatic aberration correction.

2. The color difference correction method of a high-resolution rowland circle optical system as claimed in claim 1, wherein said high-resolution rowland circle optical system includes: the optical slit (2), the Rowland circle (3), the holographic concave grating (4) and seven photoelectric sensors are all positioned on the Rowland circle (3); the optical slit (2) receives light focused by the plano-convex lens (1), the light is projected on the holographic concave grating (4) to carry out dispersion in the meridian direction, and diffracted light with characteristic wavelengths corresponding to each element after dispersion is received by the seven paths of photoelectric sensors.

3. A chromatic aberration correction method of a high-resolution rochanter optical system according to claim 2, wherein the optical slit (2) is a line slit, and the optical slit (2) is parallel to the scribing direction of the holographic concave grating (4).

4. The method for correcting chromatic aberration of a high-resolution rowland circle optical system according to claim 2, wherein said seven-path photosensor includes: the photoelectric sensor comprises a 1 st band photoelectric sensor (5), a 2 nd band photoelectric sensor (6), a 3 rd band photoelectric sensor (7), a 4 th band photoelectric sensor (8), a 5 th band photoelectric sensor (9), a 6 th band photoelectric sensor (10) and a 7 th band photoelectric sensor (11).

5. The method for correcting chromatic aberration of a high-resolution rowland circle optical system according to claim 2, wherein the method for dividing the characteristic wavelength corresponding to each element into bands comprises:

obtaining diffraction angles of each element characteristic wavelength, and arranging the diffraction angles in sequence;

setting a threshold span to divide the wave band, and dividing the wave band into seven sections to be received by the seven-path photoelectric sensor.

6. The method for correcting chromatic aberration of a high-resolution rowland circle optical system as claimed in claim 5, wherein the method for establishing a center wavelength for each band includes:

based on the divided wave bands, the diffraction angles of the maximum characteristic wavelength and the minimum characteristic wavelength in the wave bands are averaged, and a central wavelength is established by combining a grating equation to obtain each wave band.

7. The method for correcting chromatic aberration of a high-resolution rowland circle optical system according to claim 1, wherein the method for acquiring the shift amount of each of the center wavelengths is:

wherein EFL (lambda) is the offset of each center wavelength, X is the thickness of the plano-convex lens, r ₁ The curvature radius of the plane convex lens curved surface is D, the clear aperture of the entrance hole is n ₁ For the corresponding characteristic wavelength lambda in the material CaF ₂ In (a) and M is an expression for the wavelength lambda, i ₁ Is the angle of incidence.

8. The method for correcting chromatic aberration of high-resolution rochanter optical system according to claim 2, wherein the step of setting a standing weight for a characteristic wavelength of each band, and fitting and optimizing the relative positions of imaging points after establishing the shift of each wavelength, to obtain an optimal position of an image plane comprises:

introducing offset on the basis of the original imaging point to obtain the relative position of the imaging point after each wavelength is offset;

setting a vertical weight for characteristic wavelengths of each wave band, and carrying out weighted least square fitting optimization according to the duty ratio of each weight based on the relative positions of imaging points after each wavelength is deviated to obtain the optimal position of the image plane.

9. The method for correcting chromatic aberration of a high-resolution rochon optical system according to claim 1, wherein the method for obtaining a center offset and an offset tilt angle of an image plane in the high-resolution rochon optical system is:

wherein AB is the center offset distance, PBP' is the offset inclination angle, f is the curvature radius of the holographic concave grating, the angle theta_Cenλ is the diffraction angle of the center wavelength of each wave band, and k_Wei and b_Wei are the slope and intercept of projection of the sensor photosurface on the meridian plane after fitting by the weighted least square method.