Simulation model for inhibiting unnecessary interference effect of optical system

Abstract

The invention relates to a simulation model for inhibiting the unnecessary interference effect of an optical system, and the transmission matrix of each layer of film of the simulation model meets # imgabs0 #. The simulation model for inhibiting the unnecessary interference effect of the optical system can simulate and predict the interference effect possibly occurring in different working environments in a design stage; moreover, the design parameters of the optical element can be dynamically adjusted to adapt to constantly changing working conditions, recognition is carried out in advance, unnecessary interference is avoided, and therefore it is ensured that the system can still keep high precision and high stability in a changeable working environment.

Description

Technical Field

[0001] The present invention relates to the technical field of optical device design and optimization, and in particular to a simulation model for suppressing unnecessary interference effects of an optical system. Background Art

[0002] Optical interference occurs when two or more coherent light waves meet, and they are superimposed or destructive according to the phase relationship, resulting in changes in intensity. Due to the optical path difference, film thickness and refractive index of the thin film structure, the propagation and reflection of the light wave in the multilayer film structure will change in phase, thereby causing interference effects. Different factors will cause the interference effect to exhibit different characteristics. With the rapid development of precision optical technology, the demand for compact optical systems in space exploration, satellite communications and high-performance sensors is increasing. As the core component of these systems, multilayer film optical elements are widely used in the control of transmittance, reflectivity and filtering characteristics due to their unique advantages in thin film structure regulation. However, compact design usually requires extremely small spacing between optical elements, and in practical applications, external factors such as temperature changes may cause fluctuations in the spacing between devices, thereby causing interference effects between thin films. This interference effect will affect the stability and measurement accuracy of the optical system. Therefore, how to effectively suppress and control the interference effect has become a major challenge in the design of compact optical systems.

[0003] Existing optical system optimization solutions mainly reduce interference effects by adjusting the design parameters of multilayer film optical elements, especially the thickness and refractive index of the film layers. Specifically, multilayer film optical elements are composed of several thin film layers, and the thickness of each film layer and the refractive index of the material will affect the reflection and transmission behavior of light. By adjusting the thickness and refractive index of these film layers, the transmittance (i.e. the ability of light to pass through) and reflectivity (i.e. the degree of light reflection) of the optical element can be effectively optimized, thereby reducing the interference phenomenon caused by the small spacing between optical elements.

[0004] Although existing solutions can optimize optical components under fixed design conditions, they often lack the ability to fully predict and dynamically adjust interference effects when faced with changing working environments. These traditional methods usually assume that optimization is performed under certain specific environmental conditions, such as evaluating interference effects at room temperature and pressure, or at the optical component spacing and material properties that have been determined during the design phase. However, in actual applications, optical systems often face complex working environments, including factors such as temperature changes, humidity fluctuations, mechanical vibrations, and slight changes in the spacing between optical components.

[0005] In such a changing environment, the working conditions of the optical system are constantly changing, which may cause fluctuations in the film layer spacing, or changes in external factors such as light source and temperature, which will have a significant impact on the interference effect. Traditional solutions can usually only determine whether unnecessary or non-negligible interference effects will occur under fixed conditions, but cannot predict and respond in advance to the interference risks that may occur during actual applications. For example, in an optical system with extremely small spacing, due to temperature increase or mechanical vibration, the thickness of the film layer and the refractive index of the material may change slightly. These changes will change the propagation path of light, thereby causing unstable interference effects and affecting the stability and accuracy of the system.

[0006] Therefore, in the face of various changes in practical applications, existing solutions cannot provide sufficient flexibility and accuracy to predict the interference effect. They often rely on static design optimization and ignore the dynamic impact of environmental factors. Summary of the invention

[0007] The present invention aims to solve the technical problem of interference effect caused by variation in the spacing between optical elements and fluctuations in external environmental factors in the optical system in the prior art, and to provide a simulation model for suppressing unnecessary interference effect in the optical system.

[0008] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0009] A simulation model for suppressing unnecessary interference effects in an optical system, wherein the transmission matrix of each film layer of the simulation model satisfies:

[0010] For the i-th film, its transmission matrix is:

[0011]

[0012] in:

[0013]

[0014] M is the transmission matrix of the i-th film; δ i is the phase shift; λ is the wavelength of light; a is the incident angle of light in the incident medium; d is the film thickness of the i-th film; θ i is the incident angle of light in the i-th film; n i is the refractive index of the i-th film.

[0015] In the above technical solution, the total transmission matrix of the simulation model satisfies:

[0016]

[0017] in,

[0018] The multilayer film in front of the substrate 1 is represented by: n 11 , n 12 …n 1n ;d 11 , d 12 …n 1n ;

[0019] Substrate 1 is represented by: n1; d1;

[0020] The multilayer films behind the substrate 1 are represented as follows: 21 , n 22 …n 2l ;d 21 , d 22 …n 2l ;

[0021] Between substrate 1 and substrate 2 is represented as: n2, d2;

[0022] The multilayer films in front of the substrate 2 are represented as: 31 , n 32 …n 3m ;d 31 , d 32 …n 3m ;

[0023] Substrate 2 is represented by: n3; d3;

[0024] The multilayer films behind the substrate 2 are represented as: 41 , n 42 …n 4k ;d 41 , d 42 …n 4k ;

[0025] Between substrate 2 and substrate 3 is represented as: n4, d4;

[0026] The multilayer films in front of substrate n are represented as: 2n-11 , n 2n-12 …n 2n-1j ;d 2n-11 , d 2n-12 …n 2n-1j ; Substrate n is expressed as: n 2n-1 ;d 2n-1 ;

[0027] The multilayer films behind the substrate n are represented as: 2n1 , n 2n2 …n 2np ;d 2n1 , d 2n2 …n 2np ;

[0028] The wavelength of light is expressed as: λ;

[0029] The total transmission matrix of the multilayer film in front of substrate 1 is expressed as: M front1 ;

[0030] The transmission matrix of substrate 1 is expressed as: M substrate1 ;

[0031] The total transmission matrix of the multilayer film behind substrate 1 is expressed as: M back1 ;

[0032] The total transmission matrix of the multilayer film in front of substrate 2 is expressed as: front2 ;

[0033] The transmission matrix of substrate 2 is expressed as: M substrate2 ;

[0034] The total transmission matrix of the multilayer film behind substrate 2 is expressed as: M back2 ;

[0035] The total transmission matrix of the multilayer film in front of substrate n is expressed as: M frontn ;

[0036] The transmission matrix of substrate n is expressed as: M substrate3 ;

[0037] The total transmission matrix of the multilayer film behind substrate n is expressed as: M backn .

[0038] In the above technical solution, the total light intensity of the simulation model satisfies:

[0039]

[0040] Among them, M total is the total transmission matrix; I total is the final total output light intensity; R eff is the total reflectivity.

[0041] In the above technical solution, the simulation model is applicable to multilayer film optical elements.

[0042] The present invention has the following beneficial effects:

[0043] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention can simulate and predict the interference effects that may occur in different working environments during the design phase, and can dynamically adjust the design parameters of optical elements to adapt to changing working conditions, identify and avoid unnecessary interference in advance, and thus ensure that the system can maintain high precision and high stability in a changing working environment.

[0044] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention can identify and predict the interference effects of optical systems in a variable environment in advance during the design stage by constructing an accurate model of compact optical devices, especially when the spacing between optical elements changes and external factors fluctuate. Not only static parameters are considered in the early stages of design, but also potential interference risks can be identified in advance based on dynamic changes that may occur in actual applications, and unnecessary interference effects can be avoided by optimizing the design. Traditional methods mostly rely on static design optimization and cannot fully foresee and adapt to changes in different working environments. The present invention, through modeling and simulation analysis, can predict interference effects in real time under a variety of working conditions, providing a more accurate adjustment solution for system design.

[0045] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention has stronger adaptability and flexibility, and can dynamically adjust the structure and parameters of optical components according to different design requirements and actual application environments. In actual operation, the system may face factors such as temperature fluctuations, mechanical vibrations, and aging of optical components, which will affect the stability and performance of the optical system. By adjusting the design of optical devices in real time, the present invention can significantly improve the robustness of the system, ensuring that the optical system can still maintain high-precision measurement and stable operation under these complex and changeable environmental conditions.

[0046] The simulation model for suppressing unnecessary interference effects in optical systems of the present invention, through forward-looking design and dynamic optimization, gives the optical system higher predictability and controllability, breaks through the limitations of traditional methods in complex environments, and provides a more reliable, flexible and efficient solution. This innovative idea is not only of great significance in improving the performance and stability of optical systems, but also provides a more accurate and controllable optimization path for the design of compact optical systems, significantly improving the overall reliability and practical value of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0048] Figure 1 Schematic diagram of the compact optical system structure.

[0049] Figure 2 Schematic diagram of simulation results when the substrate spacing increases from 5μm to 1nm interval.

[0050] Figure 3 Schematic diagram of simulation results when the substrate spacing increases from 1 mm to 1 nm.

[0051] Figure 4Schematic diagram of simulation results when the film refractive index changes as the substrate spacing increases from 5μm to 1nm intervals.

[0052] Figure 5 Schematic diagram of the internal structure of the irradiance spectrometer.

[0053] Figure 6 This is a schematic diagram of the actual on-orbit data of the irradiance spectrometer.

[0054] Figure 7-9 They are schematic diagrams of ground experimental equipment.

[0055] Fig.10 Schematic diagram of the normalization process of the positive filter.

[0056] Fig.11 Schematic diagram of the normalization processing of the reflection filter.

[0057] Fig.12 Schematic diagram of normalization processing when the filter is placed upright without adding a spacer.

[0058] Fig.13 Schematic diagram of the normalization process of adding a spacer when placing the filter upright. DETAILED DESCRIPTION

[0059] The inventive concept of the present invention is:

[0060] The interference simulation model based on the compact multilayer film optical system element of the present invention takes into account the complex structure of the multilayer film and multiple substrates, and can accurately simulate the interference effect of light of different wavelengths in the multilayer film system. Through this model, the influence of parameters such as film thickness, refractive index and gap thickness on the interference intensity can be deeply analyzed, providing a theoretical basis for related applications.

[0061] The present invention is described in detail below with reference to the accompanying drawings.

[0062] 1. Theoretical Model

[0063] When studying the interference problem of multilayer films in compact optical systems, the system can be regarded as consisting of multiple substrates and multilayer films, such as Figure 1 shown.

[0064] Calculate the transmission matrix for each membrane layer:

[0065] For the i-th film, its transmission matrix is:

[0066]

[0067] in:

[0068]

[0069] M is the transmission matrix of the i-th film; δ i is the phase shift; λ is the wavelength of light; a is the incident angle of light in the incident medium; d is the film thickness of the i-th film; θ i is the incident angle of light in the i-th film; n i is the refractive index of the i-th film.

[0070] Calculate the total transmission matrix and total light intensity of this model:

[0071] M total =

[0072] M back1 ×M substrate1 ×M front1 ×M back2 ×M substrate2 ×M front2 ×

[0073] ……M backn ×M substraten ×M frontn

[0074]

[0075] like Figure 1 As shown,

[0076] The multilayer films in front of the substrate 1 are represented as follows: 11 , n 12 …n 1n ;d 11 , d 12 …n 1n ;

[0077] Substrate 1 is represented by: n1; d1;

[0078] The multilayer films behind the substrate 1 are represented as follows: 21 , n 22 …n 2l ;d 21 , d 22 …n 2l ;

[0079] Between substrate 1 and substrate 2 is represented as: n2, d2;

[0080] The multilayer films in front of the substrate 2 are represented as: 31 , n 32 …n 3m ;d 31 , d 32 …n 3m ;

[0081] Substrate 2 is represented by: n3; d3;

[0082] The multilayer films behind the substrate 2 are represented as: 41 , n 42 …n 4k ;d 41 , d 42 …n 4k ;

[0083] Between substrate 2 and substrate 3 is represented as: n4, d4;

[0084] The multilayer films in front of substrate n are represented as: 2n-11 , n 2n-12 …n 2n-1j ;d 2n-11 , d 2n-12 …n 2n-1j ; Substrate n is expressed as: n 2n-1 ;d 2n-1 ;

[0085] The multilayer films behind the substrate n are represented as: 2n1 , n 2n2 …n 2np ;d 2n1 , d 2n2 …n 2np ;

[0086] The wavelength of light is expressed as: λ;

[0087] The total transmission matrix of the multilayer film in front of substrate 1 is expressed as: M front1 ;

[0088] The transmission matrix of substrate 1 is expressed as: M substrate1 ;

[0089] The total transmission matrix of the multilayer film behind substrate 1 is expressed as: M back1 ;

[0090] The total transmission matrix of the multilayer film in front of substrate 2 is expressed as: front2 ;

[0091] The transmission matrix of substrate 2 is expressed as: M substrate2 ;

[0092] The total transmission matrix of the multilayer film behind substrate 2 is expressed as: M back2 ;

[0093] The total transmission matrix of the multilayer film in front of substrate n is expressed as: M frontn ;

[0094] The transmission matrix of substrate n is expressed as: M substrate3 ;

[0095] The total transmission matrix of the multilayer film behind substrate n is expressed as: M backn .

[0096]

[0097] Among them, M total is the total transmission matrix; I total is the final total output light intensity; R eff is the total reflectivity.

[0098] The above is a model and formula derivation applicable to any conditions.

[0099] This model can be applied to any type of multilayer optical element. To demonstrate its application, the following is an example of its use.

[0100] During the component design process, if you need to consider the impact of different influencing factors on instrument performance, you can enter the corresponding values ​​according to different conditions. For example, if you want to test whether the current spacing between two components will cause unnecessary interference effects, you can first enter the current spacing d1 and calculate the interference intensity I1. Then, by changing the spacing equidistantly, d2, d3, d4, d5 (the specific changes should be coordinated with the actual instrument conditions), you can get I2, I3, I4, I5 respectively. By comparing the ratios of I2, I3, I4, I5 with I1, observe whether interference occurs, so as to clarify whether there is unnecessary interference under the condition of d1. The same applies to the remaining influencing factors.

[0101] 2. Simulation Model

[0102] Based on the theoretical model above, a multilayer thin film interference simulation model was established through MATLAB to simulate the interference intensity distribution under different parameter conditions. The model takes into account the reflection and transmission effects of the multilayer film structure on light, and calculates the interference phenomenon at different wavelengths through the transmission matrix method and Fresnel formula. In the following analysis, we will explore the impact of different parameters on the interference pattern.

[0103] Note: The currently input parameters are consistent with the instrument structure parameters of the on-orbit irradiance spectrometer.

[0104] Based on the theoretical model analysis of the present invention, an interference simulation model was established through MATLAB, aiming to simulate the interference intensity distribution under different parameter conditions.

[0105] Figure 2 , 3 The following are the effects of the substrate spacing on interference. When the substrate spacing increases from 5μm to 1nm, the simulation results are as follows: Figure 2, we can see obvious interference phenomenon. When the substrate spacing increases from 1mm to 1nm, the simulation results are as follows Figure 3 , we can see that the interference phenomenon disappears obviously.

[0106] Figure 4 To analyze the effect of the film refractive index on interference, the substrate spacing is still kept from 5μm to 1nm. When the film refractive index is changed, the simulation results are shown in the figure, and it can be seen that the interference phenomenon disappears significantly.

[0107] The present invention uses the existing design of the on-orbit irradiance spectrometer and on-orbit data to verify the rationality and feasibility of the model. The simulation results, on-orbit data and ground experiments all reasonably prove the rationality and feasibility of the model.

[0108] 1. On-orbit data

[0109] In the actual measured data of the on-orbit irradiance spectrometer, interference phenomena consistent with the simulation results were observed. This is due to the structure of a flat window and a filter (or attenuator) at the front end of the optical system. After the extreme ultraviolet light is filtered out by the flat window, the sunlight enters the spectrometer filter (or attenuator), and then enters the back-end optical system to complete the solar spectrum detection. In order to make the instrument structure more compact and meet the requirements of miniaturization design, the flat window and the attenuation are tightly fitted. However, although the instrument ensures that the temperature is controlled within an appropriate range through reasonable thermal design during operation, thereby meeting the dimensional stability requirements of the optical components and optomechanical structures, slight temperature changes are still inevitable. These temperature fluctuations will cause the rigid displacement of the flat window and the attenuation plate, thereby destroying the original close fit between them, resulting in changes in interference conditions and unnecessary interference effects. Figure 5 is the internal structure (a part) of the irradiance spectrometer, Figure 6 It is the actual on-orbit data of the irradiance spectrometer.

[0110] 2. Ground Experiment

[0111] Figure 7-9 Shown are the ground experimental equipment.

[0112] Experiment 1: Verification experiment on the effect of spacing change on interference suppression effect

[0113] The experimental results are as follows:

[0114] Fig.10 This is the normalized processing diagram of the positive filter. Fig.11 This is the normalized processing diagram of the reflection filter.

[0115] The experimental results show that when the refractive index of the multilayer film is changed by using positive and negative filters, the interference effect can indeed be effectively suppressed.

[0116] Experiment 2: Verification experiment on the effect of refractive index on interference suppression effect

[0117] The experimental results are as follows:

[0118] Fig.12 This is the normalized processing diagram when the filter is placed upright without adding a spacer. Fig.13 This is the normalized processing diagram with a spacer added when the filter is placed upright.

[0119] It can be seen from the experimental results that when the distance between the two devices is increased, the interference effect is also effectively suppressed.

[0120] In summary, the substrate spacing and the film refractive index are the key factors affecting the interference phenomenon. By using the model of the present invention, the interference effects that may occur in compact optical systems under different working conditions can be effectively predicted and identified, especially when the spacing between optical elements changes and external environmental factors fluctuate.

[0121] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention can simulate and predict the interference effects that may occur in different working environments during the design phase, and can dynamically adjust the design parameters of optical elements to adapt to changing working conditions, identify and avoid unnecessary interference in advance, and thus ensure that the system can maintain high precision and high stability in a changing working environment.

[0122] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention can identify and predict the interference effects of optical systems in a variable environment in advance during the design stage by constructing an accurate model of compact optical devices, especially when the spacing between optical elements changes and external factors fluctuate. Not only static parameters are considered in the early stages of design, but also potential interference risks can be identified in advance based on dynamic changes that may occur in actual applications, and unnecessary interference effects can be avoided by optimizing the design. Traditional methods mostly rely on static design optimization and cannot fully foresee and adapt to changes in different working environments. The present invention, through modeling and simulation analysis, can predict interference effects in real time under a variety of working conditions, providing a more accurate adjustment solution for system design.

[0123] The simulation model for suppressing unnecessary interference effects of optical systems of the present invention has stronger adaptability and flexibility, and can dynamically adjust the structure and parameters of optical components according to different design requirements and actual application environments. In actual operation, the system may face factors such as temperature fluctuations, mechanical vibrations, and aging of optical components, which will affect the stability and performance of the optical system. By adjusting the design of optical devices in real time, the present invention can significantly improve the robustness of the system, ensuring that the optical system can still maintain high-precision measurement and stable operation under these complex and changeable environmental conditions.

[0124] The simulation model for suppressing unnecessary interference effects in optical systems of the present invention, through forward-looking design and dynamic optimization, gives the optical system higher predictability and controllability, breaks through the limitations of traditional methods in complex environments, and provides a more reliable, flexible and efficient solution. This innovative idea is not only of great significance in improving the performance and stability of optical systems, but also provides a more accurate and controllable optimization path for the design of compact optical systems, significantly improving the overall reliability and practical value of the system.

[0125] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A simulation model for suppressing unnecessary interference effects in an optical system, characterized in that: The transmission matrix of each layer of the simulation model satisfies: For the i-th film, its transmission matrix is: in: M is the transmission matrix of the i-th film; δ i is the phase shift; λ is the wavelength of light; a is the incident angle of light in the incident medium; d is the film thickness of the i-th film; θ i is the incident angle of light in the i-th film; n i is the refractive index of the i-th film.

2. The simulation model for suppressing unnecessary interference effects of an optical system according to claim 1, characterized in that: The total transmission matrix of the simulation model satisfies: in, The multilayer films in front of the substrate 1 are represented as follows: 11 , n 12 …n 1n ;d 11 , d 12 …n 1n ; Substrate 1 is represented by: n1; d1; The multilayer films behind the substrate 1 are represented as follows: 21 , n 22 …n 2l ;d 21 , d 22 …n 2l ; Between substrate 1 and substrate 2 is represented as: n2, d2; The multilayer films in front of the substrate 2 are represented as: 31 , n 32 …n 3m ;d 31 , d 32 …n 3m ; Substrate 2 is represented by: n3; d3; The multilayer films behind the substrate 2 are represented as: 41 , n 42 …n 4k ;d 41 , d 42 …n 4k ; Between substrate 2 and substrate 3 is represented as: n4, d4; The multilayer films in front of substrate n are represented as: 2n-11 , n 2n-12 …n 2n-1j ;d 2n-11 , d 2n-12 …n 2n-1j ; Substrate n is expressed as: n 2n-1 ;d 2n-1 ; The multilayer films behind the substrate n are represented as: 2n1 , n 2n2 …n 2np ;d 2n1 , d 2n2 …n 2np ; The wavelength of light is expressed as: λ; The total transmission matrix of the multilayer film in front of substrate 1 is expressed as: M front1 ; The transmission matrix of substrate 1 is expressed as: M substrate1 ; The total transmission matrix of the multilayer film behind substrate 1 is expressed as: M back1 ; The total transmission matrix of the multilayer film in front of substrate 2 is expressed as: front2 ; The transmission matrix of substrate 2 is expressed as: M substrate2 ; The total transmission matrix of the multilayer film behind substrate 2 is expressed as: M back2 ; The total transmission matrix of the multilayer film in front of substrate n is expressed as: M frontn ; The transfer matrix of substrate n is expressed as: M substrate3 ; The total transmission matrix of the multilayer film behind substrate n is expressed as: M backn .

3. The simulation model for suppressing unnecessary interference effects of an optical system according to claim 1, characterized in that: The total light intensity of the simulation model satisfies: Among them, M total is the total transmission matrix; I total is the final total output light intensity; R eff is the total reflectivity.

4. The simulation model for suppressing unnecessary interference effects of an optical system according to any one of claims 1 to 3, characterized in that: This simulation model is applicable to multilayer optical components.

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