A simulation model for the suppression of unwanted interference effects in optical systems

Abstract

The application relates to a simulation model for suppressing unnecessary interference effects of an optical system, wherein the transmission matrix of each layer of the simulation model satisfies: the simulation model for suppressing unnecessary interference effects of an optical system can simulate and predict possible interference effects under different working environments in the design stage, and can dynamically adjust the design parameters of the optical element to adapt to the changing working conditions, so that unnecessary interference can be identified and avoided in advance, and the system can still maintain high precision and high stability in the variable 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, adding or destructing each other depending on their phase relationship, resulting in intensity variations. Due to differences in optical path length, film thickness, and refractive index within the thin film structure, light waves propagating and reflecting within a multilayer film structure undergo phase shifts, triggering interference effects. Different factors can lead to different characteristics of interference effects. With the rapid advancement of precision optical technology, demand for compact optical systems is increasing in areas such as space exploration, satellite communications, and high-performance sensors. Multilayer film optical elements, as core components of these systems, are widely used to control transmittance, reflectivity, and filtering properties due to their unique advantages in thin film structure tuning. However, compact designs typically require extremely small spacing between optical components. In practical applications, external factors such as temperature fluctuations can cause fluctuations in the device spacing, leading to interference effects between the thin films. This interference effect can compromise the stability of the optical system and measurement accuracy. Therefore, effectively suppressing and controlling interference effects has become a major challenge in the design of compact optical systems.

[0003] Existing optical system optimization solutions primarily reduce interference effects by adjusting the design parameters of multilayer film optical components, particularly the thickness and refractive index of the film layers. Specifically, multilayer film optical components are composed of several thin film layers, and the thickness and refractive index of each layer 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 component can be effectively optimized, thereby reducing the interference phenomenon caused by the small spacing between optical components.

[0004] While existing approaches 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 operating environments. These traditional methods typically assume optimization under certain specific environmental conditions, such as room temperature and pressure, or evaluating interference effects based on the spacing and material properties of optical components determined during the design phase. However, in practical applications, optical systems often face complex operating environments, including temperature changes, humidity fluctuations, mechanical vibrations, and subtle changes in the spacing between optical components.

[0005] In this ever-changing environment, the operating 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 sources and temperature. These changes 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 application. For example, in an optical system with extremely small spacing, due to temperature increases or mechanical vibrations, 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, existing solutions cannot provide sufficient flexibility and accuracy to predict interference effects in the face of various changes in real applications. 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 effects caused by changes in the spacing between optical elements and fluctuations in external environmental factors in the prior art optical system, and to provide a simulation model for suppressing unnecessary interference effects 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 in 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 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: n 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 follows: 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 follows: n 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 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: M 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 in optical systems of the present invention can simulate and predict interference effects that may occur in different working environments during the design phase, and can dynamically adjust the design parameters of optical components 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 in optical systems of the present invention, by constructing an accurate model of compact optical devices, can identify and predict the interference effects of optical systems in variable environments in advance during the design phase, especially when the spacing between optical elements changes and external factors fluctuate. Not only does it take into account the static parameters in the early stages of design, but it can also identify potential interference risks in advance based on dynamic changes that may occur in actual applications, and avoid unnecessary interference effects through optimized design. Traditional methods mostly rely on static design optimization and are unable to 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 various working conditions, providing a more accurate adjustment solution for system design.

[0045] The present invention's simulation model for suppressing unnecessary interference effects in optical systems offers enhanced adaptability and flexibility, enabling dynamic adjustment of the structure and parameters of optical components based on varying design requirements and actual application environments. During actual operation, the system may face factors such as temperature fluctuations, mechanical vibrations, and aging of optical components, all of which can affect the stability and performance of the optical system. By adjusting the design of optical components in real time, the present invention significantly improves the robustness of the system, ensuring that the optical system can maintain high-precision measurements and stable operation under these complex and changing environmental conditions.

[0046] The simulation model for suppressing unnecessary interference effects in optical systems, developed in this paper, uses forward-looking design and dynamic optimization to enhance predictability and controllability. This model overcomes the limitations of traditional methods in complex environments and provides a more reliable, flexible, and efficient solution. This innovative approach is not only significant in improving the performance and stability of optical systems, but also provides a more precise and controllable optimization path for the design of compact optical systems, significantly enhancing the overall reliability and practical value of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described in detail below with reference to 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 intervals.

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

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

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

[0053] Figure 6 Schematic diagram of the actual on-orbit data of the irradiance spectrometer.

[0054] Figure 7-9 Schematic diagrams of ground experimental equipment.

[0055] Figure 10 Schematic diagram of the normalization processing of the positive filter.

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

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

[0058] Figure 13 Schematic diagram of the normalization process of adding spacers when placing the filter upright. DETAILED DESCRIPTION

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

[0060] The proposed interference simulation model for compact multilayer optical system components takes into account the complex structure of the multilayer films and multiple substrates, accurately simulating the interference effects of light of different wavelengths in the multilayer film system. This model enables in-depth analysis of the impact of parameters such as film thickness, refractive index, and gap thickness on interference intensity, providing a theoretical basis for related applications.

[0061] The present invention will be 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 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: n 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 follows: 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 follows: n 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 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: M 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 calculations of any multilayer optical component. To illustrate its application, the following is an example.

[0100] During component design, if you need to consider the impact of different factors on instrument performance, you can enter corresponding values ​​based on different conditions. For example, to test whether the current spacing between two components will cause unnecessary interference, you can first enter the current spacing d1 and calculate the interference intensity I1. Next, by changing the spacing by equal intervals, d2, d3, d4, and d5 (the specific changes should be coordinated with the actual instrument conditions), you can obtain I2, I3, I4, and I5, respectively. By comparing the ratios of I2, I3, I4, and I5 with I1, you can observe whether interference occurs, thereby clarifying whether unnecessary interference exists under the condition of d1. The same principle applies to other influencing factors.

[0101] 2. Simulation Model

[0102] Based on the theoretical model described above, a multilayer thin film interference simulation model was developed using MATLAB to simulate the interference intensity distribution under different parameter conditions. This model takes into account the reflection and transmission effects of the multilayer film structure on light and calculates the interference phenomena at different wavelengths using the transfer matrix method and Fresnel equations. In the following analysis, we will explore the effects of different parameters on the interference pattern.

[0103] Note: The currently entered 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 using MATLAB to simulate the interference intensity distribution under different parameter conditions.

[0105] Figure 2 、 3 The following are the effects of 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's refractive index on interference, the substrate spacing is kept constant, increasing from 5μm to 1nm intervals. When the film's refractive index is changed, the simulation results are shown in the figure, and the interference phenomenon can be seen to disappear 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] Interference phenomena consistent with simulation results were observed in the actual measured data of the on-orbit irradiance spectrometer. This is due to the use of a flat window and filter (or attenuator) structure at the front end of the optical system. After filtering out the extreme ultraviolet light through the flat window, sunlight enters the spectrometer filter (or attenuator) and then enters the back-end optical system to complete the solar spectrum detection. To make the instrument structure more compact and meet the requirements of miniaturization, the flat window and attenuator fit tightly together. However, although reasonable thermal design ensures that the temperature is controlled within an appropriate range during operation, thereby meeting the dimensional stability requirements of the optical components and optomechanical structure, slight temperature fluctuations are inevitable. These temperature fluctuations can cause rigid displacement of the flat window and attenuator, thereby disrupting their original close contact, resulting in changes in the interference conditions and unnecessary interference effects. Figure 5 is the internal structure (part) of the irradiance spectrometer, Figure 6 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] Figure 10 This is the normalized processing diagram of the positive filter. Figure 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 placing the filter in the positive and negative directions, 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] Figure 12 This is the normalized processing diagram when the filter is placed upright without adding a spacer. Figure 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, substrate spacing and film refractive index are key factors influencing interference phenomena. The proposed model can effectively predict and identify interference effects that may occur in compact optical systems under different operating conditions, especially when the spacing between optical elements varies and external environmental factors fluctuate.

[0121] The simulation model for suppressing unnecessary interference effects in optical systems of the present invention can simulate and predict interference effects that may occur in different working environments during the design phase, and can dynamically adjust the design parameters of optical components 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 in optical systems of the present invention, by constructing an accurate model of compact optical devices, can identify and predict the interference effects of optical systems in variable environments in advance during the design phase, especially when the spacing between optical elements changes and external factors fluctuate. Not only does it take into account the static parameters in the early stages of design, but it can also identify potential interference risks in advance based on dynamic changes that may occur in actual applications, and avoid unnecessary interference effects through optimized design. Traditional methods mostly rely on static design optimization and are unable to 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 various working conditions, providing a more accurate adjustment solution for system design.

[0123] The present invention's simulation model for suppressing unnecessary interference effects in optical systems offers enhanced adaptability and flexibility, enabling dynamic adjustment of the structure and parameters of optical components based on varying design requirements and actual application environments. During actual operation, the system may face factors such as temperature fluctuations, mechanical vibrations, and aging of optical components, all of which can affect the stability and performance of the optical system. By adjusting the design of optical components in real time, the present invention significantly improves the robustness of the system, ensuring that the optical system can maintain high-precision measurements and stable operation under these complex and changing environmental conditions.

[0124] The simulation model for suppressing unnecessary interference effects in optical systems, developed in this paper, uses forward-looking design and dynamic optimization to enhance predictability and controllability. This model overcomes the limitations of traditional methods in complex environments and provides a more reliable, flexible, and efficient solution. This innovative approach is not only significant in improving the performance and stability of optical systems, but also provides a more precise and controllable optimization path for the design of compact optical systems, significantly enhancing the overall reliability and practical value of the system.

[0125] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A simulation model for suppressing unnecessary interference effects in an optical system, characterized in that: The transmission matrix of each membrane layer of this 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 i is the thickness of the i-th film layer; θ i is the incident angle of light in the i-th film; n i is the refractive index of the i-th film; 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: n 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 follows: 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 follows: n 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: M 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 transmission matrix of substrate n is expressed as: M substraten ; The total transmission matrix of the multilayer film behind substrate n is expressed as: M backn ; 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.

2. The simulation model for suppressing unnecessary interference effects of an optical system according to claim 1, characterized in that: This simulation model is suitable for multilayer optical components.

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