Multi-element partition mapping spectrum modulation system optimization method

Abstract

The invention provides a multivariate partition mapping spectrum modulation system optimization method, and belongs to the technical field of optical testing, and the method comprises the steps: 1, obtaining the specific structure of the system, the system comprising a front collimation and beam expanding system, a multi-size slit, a biprism symmetric beam splitting system and a DMD; after the DMD divides a space area, optimization design is carried out on a front collimation and beam expanding system, a multi-size slit and a beam splitting system with biprisms symmetrically arranged. On the basis of DMD space region division, an off-axis two-reflection reflection type front collimation and beam expanding system is designed, the size of a multi-size slit is determined, a biprism symmetrically-arranged beam splitting system is designed, and multi-element division and independent control of a spectrum modulation region and single-channel input and four-channel output of fixed star optical radiation characteristics are achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical testing technology, and in particular to a multi-element partition mapping spectrum modulation system optimization method. Background Art

[0002] The existing large dynamic spectrum modulation system can only achieve the simultaneous modulation of a single color temperature and magnitude information, and cannot achieve the independent output of multiple color temperatures and magnitudes. In combination with the main parameters of the navigation star, this application selects the 3000K-9000K color temperature in the 450nm-1000nm spectrum range as the simulation range. The spectral energy ratio of 3000K color temperature is the largest, and the ratio of the highest energy to the lowest energy is , that is, ideally, the modulation ratio of the minimum unit weight of spectral simulation is greater than 6.25 times. According to the spectral simulation accuracy, the spectral simulation error is set to be within 4% with the goal of being better than the spectral simulation error of related technologies at home and abroad. The modulation accuracy of the radiation coefficient subdivision of the minimum unit of spectral simulation should be better than 4% of 6.25 times, that is, the adjustment ratio should meet The radiation coefficient adjustment capability of a single DMD is 1080 times, which is much higher than the required 156.25 times.

[0003] Therefore, it is necessary to develop a multi-element partition mapping spectral modulation optical system optimization method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-region mapping spectral modulation system optimization method that can divide a spatial light modulator (DMD) into regions, with different regions being independent of each other, and realize simultaneous simulation of multiple stellar optical radiation characteristics.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A multivariate partition mapping spectral modulation system optimization method, the method comprising:

[0007] Step 1: Obtain the specific structure of the system, which includes: a pre-collimation beam expansion system, a multi-size slit, a symmetrically placed double prism spectrometer system and a DMD; according to the diffraction effect of the DMD itself, the diffraction efficiency of the diffraction grating at different spectra, the non-smoothness of the spectral radiation distribution of the incident light source, and the possible overflow of the adjacent area beam, it is necessary to increase the modulation magnification of the single area system; the DMD array surface is divided into 4 areas along the non-dispersion direction, and the resolution of the DMD is 1920×1080. At this time, the resolution of each area is 1920×270, that is, the maximum adjustment magnification of the radiation coefficient of the minimum unit of spectral simulation is 270 times, and the theoretical spectral simulation error is 6.25 / 270≈2.31%; after the DMD is divided into spatial areas, the pre-collimation beam expansion system, the multi-size slit and the symmetrically placed double prism spectrometer system are optimized;

[0008] Step 2: Optimize the design of the front collimation and beam expansion system. The front collimation and beam expansion system adopts a reflective optical structure without chromatic aberration. According to the output beam size of the continuous laser light source, the beam diameter , the DMD array surface size in the non-dispersion direction is It can be calculated that the magnification of the pre-collimation beam expansion system is not less than 4.08 times, and the system magnification is times;

[0009] Step 3: Optimize the design of multi-sized slits. This application sets two slits in the same area: a wide slit with a size of 0.2 mm and a narrow slit with a size of 0.01 mm. The same slit groups are set in different areas to compensate for the modulation interference between adjacent micromirror pixel groups on the DMD array surface.

[0010] Step 4: Optimize the design of the symmetrically placed double prisms splitting system. The optimization process is as follows:

[0011] (1) First determine the prism material 、 ,in is the refractive index, is the Abbe number;

[0012] (2) Calculate the refractive index of the prism for each spectrum ;

[0013] (3) According to the law of refraction , calculate the emission angle of each spectrum ;

[0014] (4) Calculate the distance between the two prisms based on trigonometric functions , making the limiting wavelength and The incident height difference on the second prism is the length of the short side of the DMD;

[0015] (5) According to the distance between the two prisms , set the second prism so that it is placed completely symmetrically with the first prism.

[0016] Specifically, the material of the prism in step 4 is TIF6 with high dispersion properties.

[0017] The beneficial effects of the present invention are:

[0018] Based on the DMD spatial area division, this application designs an off-axis double-reflective reflective pre-collimation beam expansion system, determines the sizes of multi-sized slits, and designs a double-prism symmetrically placed spectroscopic system, realizing the multi-dimensional division and independent control of the spectral modulation area and the single-channel input and four-channel output of the stellar optical radiation characteristics.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram showing the composition and optical path structure of the multi-element partition mapping spectrum modulation system shown in the present invention;

[0021] Figure 2 Schematic diagram of DMD area conversion shown in the present invention;

[0022] Figure 3 This is the optical path diagram of the pre-collimation and beam expansion system shown in the present invention;

[0023] Figure 4 Schematic diagram of multi-sized slits shown in the example of the present invention;

[0024] Figure 5 This is a circuit diagram of a symmetrically placed light splitting system with two prisms as shown in the present invention;

[0025] Figure 6 This is a wide slit light trace diagram shown in the present invention;

[0026] Figure 7 This is a diagram of the narrow slit light trace shown in the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the embodiments described are some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without inventive effort shall fall within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can mean fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] The multi-element partition mapping spectrum modulation system optimization method provided in the embodiment of the present application can be applied to Figure 1 The multi-element partition mapping spectral modulation system shown in the figure includes: a pre-collimation beam expansion system, a multi-size slit, a double prism symmetrically placed spectrometer system and a DMD. The working principle of the system is to shape and expand the light beam emitted by the light source through the pre-collimation beam expansion system, and then the light beam passes through the multi-size slit and enters the double prism symmetrically placed spectrometer system for precise light beam segmentation. Finally, the light beam is arranged in sequence on the array surface of different areas of the DMD, and the color temperature and magnitude of each simulated star point are independently modulated by the DMD.

[0029] Due to the diffraction effect of the DMD itself, the diffraction efficiency of the diffraction grating at different spectra, the non-smoothness of the spectral radiation distribution of the incident light source, and the possible overflow of the adjacent area beam, it is necessary to increase the modulation magnification of the single area system. The DMD array surface is divided into 4 areas along the non-dispersion direction, see Figure 2Since the DMD selected in this application is 1920×1080, the resolution of each area is 1920×270, that is, the maximum adjustment ratio of the radiation coefficient of the smallest unit of spectral simulation is 270 times. Theoretically, the spectral simulation error is 6.25 / 270≈2.31%.

[0030] Therefore, after determining the DMD spatial area division, the multi-element partition mapping spectral modulation system optimization design method shown in this application mainly optimizes the design of the front collimation and expansion system, multi-size slits and double prism symmetrical placement splitting system.

[0031] Optimization design of pre-collimation and beam expansion system

[0032] The function of the pre-collimation and beam expansion system is to collimate and expand the outgoing beam of the continuous laser light source, improve the collimation of the outgoing beam, reduce beam overflow, and enable the entire beam to fill the DMD array surface. Therefore, the design is mainly based on the size of the DMD array surface in the non-dispersion direction.

[0033] The front collimation beam expansion system adopts a reflective optical structure without chromatic aberration, and outputs the beam size (beam diameter) of the continuous laser light source. ) and the DMD array surface size (the non-dispersive direction size is ) It can be calculated that the magnification of the pre-collimation beam expansion system is not less than 4.08 times, and the system magnification is times, please refer to the optical path of the pre-collimation beam expansion system designed in this application Figure 3 The parameters of the pre-collimation beam expansion optical system are shown in Table 1, and the parallelism of the output beam is shown in Figure 3 shown.

[0034] Table 1 Parameters of the pre-collimation and beam expansion optical system

[0035]

[0036] Table 2 Parallelism of the output beam of the pre-collimation beam expansion system

[0037]

[0038] Multi-size slit optimization design

[0039] Since the spectra between adjacent micromirror pixel groups on the DMD array surface are not completely independent and the spectra between adjacent groups have a certain degree of overlap, this application chooses to set two slits in the same area, namely a wide slit (size of 0.2mm) and a narrow slit (size of 0.01mm). The same slit groups are set in different areas to compensate for the modulation interference between adjacent micromirror pixel groups on the DMD array surface. The wide slit has two functions: one is to ensure that the system has high energy, and the other is to group-modulate the target spectrum; the narrow slit is used to compensate and fine-tune the coarsely modulated light beam. For the setting of multi-size slits, please refer to Figure 4 .

[0040] Optimized design of the spectroscopic system with symmetrically placed double prisms

[0041] This system uses a spectroscopic system with two prisms placed symmetrically. The first prism is responsible for splitting the light beam, and the second prism is responsible for collimating the separated light beams. The spectral resolution of the spectroscopic system with two prisms placed symmetrically is proportional to the distance between the prisms. In order to reduce the distance between the prisms, this application selects TIF6 with high dispersion properties as the prism material.

[0042] The optimization design process of the symmetrically placed double prisms spectrometer system is as follows:

[0043] (1) First determine the prism material , ,in is the refractive index, is the Abbe number;

[0044] (2) Calculate the refractive index of the prism for each spectrum ;

[0045] (3) According to the law of refraction , calculate the emission angle of each spectrum ;

[0046] (4) Calculate the distance between the two prisms based on trigonometric functions , making the limiting wavelength and The incident height difference on the second prism is the length of the short side of the DMD;

[0047] (5) According to the distance between the two prisms , set the second prism so that it is placed completely symmetrically with the first prism.

[0048] The parameters of the dual prism symmetrical placement spectroscopic system designed in this application are shown in Table 2. The optical path is as follows: Figure 5 shown.

[0049] in 、 It is the reflector of the front collimating and beam expanding system. For the slit group, and are the first dispersive prism and the second dispersive prism, For DMD.

[0050] Table 3 Parameters of the symmetrically placed double prisms spectroscopic system

[0051]

[0052] Although the dual prism symmetrical placement spectroscopic system is a non-imaging system, the light trace diagram can still be used to evaluate the system's spot size and spectral resolution. Figure 6 , under wide slit, the spectral resolution of the collimating spectrometer is better than 5nm at 500nm and better than 60nm at 1000nm; see Figure 7 , under narrow slit, the spectral resolution of the collimating spectrometer system is better than 1nm at 500nm and better than 10nm at 1000nm.

[0053] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A multi-element partition mapping spectrum modulation system optimization method, characterized in that: The method comprises: Step 1: Obtain the specific structure of the system, which includes: a pre-collimation beam expansion system, a multi-size slit, a symmetrically placed double prism spectrometer system and a DMD; according to the diffraction effect of the DMD itself, the diffraction efficiency of the diffraction grating at different spectra, the non-smoothness of the spectral radiation distribution of the incident light source, and the possible overflow of the adjacent area beam, it is necessary to increase the modulation magnification of the single area system; the DMD array surface is divided into 4 areas along the non-dispersion direction, and the resolution of the DMD is 1920×1080. At this time, the resolution of each area is 1920×270, that is, the maximum adjustment magnification of the radiation coefficient of the minimum unit of spectral simulation is 270 times, and the theoretical spectral simulation error is 6.25 / 270; after the DMD is divided into spatial areas, the pre-collimation beam expansion system, the multi-size slit and the symmetrically placed double prism spectrometer system are optimized; Step 2: Optimize the design of the front collimation and beam expansion system. The front collimation and beam expansion system adopts a reflective optical structure without chromatic aberration. According to the output beam size of the continuous laser light source, the beam diameter , the DMD array surface size in the non-dispersion direction is It can be calculated that the magnification of the pre-collimation beam expansion system is not less than 4.08 times, and the system magnification is times; Step 3: Optimize the design of multi-sized slits. This application sets two slits in the same area: a wide slit with a size of 0.2 mm and a narrow slit with a size of 0.01 mm. The same slit groups are set in different areas to compensate for the modulation interference between adjacent micromirror pixel groups on the DMD array surface. Step 4: Optimize the design of the symmetrically placed double prisms splitting system. The optimization process is as follows: (1) First determine the prism material ,in is the refractive index, is the Abbe number; (2) Calculate the refractive index of the prism for each spectrum ; (3) According to the law of refraction , calculate the emission angle of each spectrum ; (4) Calculate the distance between the two prisms based on trigonometric functions , making the limiting wavelength and The incident height difference on the second prism is the length of the short side of the DMD; (5) According to the distance between the two prisms , set the second prism so that it is placed completely symmetrically with the first prism.

2. The multi-element partition mapping spectrum modulation system optimization method according to claim 1, characterized in that: The material of the prism in step 4 is TIF6 with high dispersion properties.

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