Design of Optical Window Thickness and Influence of its Deformation on Multi-Spectral Camera′s Optical Performance

Yu, 方煜 Fang; Bin, 相里斌 Xiangli; Qunbo, 吕群波 Lü; Juanjuan, 景娟娟 Jing

doi:10.3788/aos201333.0422007

Cited by 3 publications

(3 citation statements)

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“…The k-ω model is used near the wall, and the k-ε model is used outside the boundary layer, containing the modified turbulence viscosity formula and the effect of turbulent shear stress. Accurately simulating the separation point and separation zone size caused by the back pressure gradient [3,5] , the method is suitable for solving the NS equations in this condition.…”

Section: Analysis Of Aerodynamic Pressure and Heat Effectmentioning

confidence: 99%

“…At the same time, as a zero-optical optical component, optical window provided an interface for the camera and the external environment, which was a part of the spectral camera optical system. In the high-altitude high-speed environment, complex flow field went through the surface of optical window and caused the aerodynamic pressure effect and aerodynamic heat effect, which affected the mechanical properties and optical properties seriously [3] . The interaction between the flow field and the optical window changed with the changing of altitude, velocity and angle of attack, which affected the air pressure and the aerodynamic heat effect on the optical window surface directly.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Semi-physical simulation of aerodynamic effect on quartz optical window in the high-altitude and high-speed environment

Fan¹,

Ming²,

Liu³

et al. 2017

AIP Conference Proceedings

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Abstract. Under the semi-physical simulation model, the aerodynamic pressure, aerodynamic heat effect taking place on the outer surface of optical window in the high-altitude and high-speed environment are analyzed. The first step, based on Reynolds Averaged Navier-Stokes equations, combining CFD simulation technology, aerodynamic pressure and aerodynamic heat loading on optical window were computed in different flying situation. Then, based on the calculated pressure and temperature data caused by aerodynamic effect on the optical window, experiments on aerodynamic effect simulation equipment were conducted. Theoretical and practical simulation results showed that the imaging performance of optical system was not affected by the deformation of Fused quartz glass under the aerodynamic circumstance. The semi-physical simulation model makes advices for the optical window design work and the detection of aviation spectral camera imaging performance.

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Section: Analysis Of Aerodynamic Pressure and Heat Effectmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Semi-physical simulation of aerodynamic effect on quartz optical window in the high-altitude and high-speed environment

Fan¹,

Ming²,

Liu³

et al. 2017

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…Therefore, analyzing the strength of the optical window is essential to ensure the quality of the optical system beam input and output and improve the stability of each precision measurement element inside the window. In summary, the analysis of optical window intensity is of utmost importance in modern optical system design and development [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Design and Optical Performance Analysis of Large-Aperture Optical Windows for Structural Vibration Reduction

Liu,

Zhang,

Han

et al. 2024

Photonics

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In order to address the issue of large-aperture optical windows operating in wind tunnel environments with dynamic responses, the damping ratio between the vibration isolation device and the mass of the system was calculated by the passive vibration isolation principle. Two isolation models using circular rubber pads and rectangular rubber pads were proposed, and it was proven that the stiffness value of the circular rubber pad is superior to that of the rectangular rubber pad. A three-dimensional model of the optical window was established using finite element analysis software to simulate the working vibration environment of the optical window. Modal analysis and harmonic response analysis were carried out on the optical system with the isolation device installed, and the nodal data of the optical glass surface changes in the optical window were input into the Zemax 19.4 optical design software in the form of Zernike coefficients to calculate imaging quality evaluation indicators. Through finite element structural analysis of the optical window and evaluation of optical performance indicators, it was demonstrated that under the background of the wind tunnel working environment, the isolation performance of the circular rubber pad in the isolation device of the optical window is superior to that of the rectangular rubber pad. This study can provide a design basis for the isolation analysis methods and isolation measures of optical windows in wind tunnel working environments. These research results have implications for the development of large-aperture optical windows in high-speed wind tunnel applications.

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冷光学大口径长波红外探测器杜瓦窗口应用设计

Zhu Haiyong,

Zeng Zhijiang,

Li Xue

et al. 2023

中国激光

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Objective Infrared remote sensing is widely used for Earth and Ocean observations. With the development of optical technology, infrared detection systems are developing toward higher resolution, hyperspectrum, and higher sensitivity. With the increasing scale of the detector array, the working wavelength also covers long waves. To ensure working performance, an infrared Dewar module must be more strictly designed to suppress stray radiation. On the one hand, to suppress stray radiation, the Dewar window adopts lowtemperature optical technology. On the other hand, the Dewar window weight increases with array size, suggesting higher requirements for the supporting strength and heat insulation of the shell. In addition, the Dewar module goes through three working states, from assembly to application, and the window deformations in these three working states are different, affecting the design of the infrared optical system.Method The temperature field of the largeaperture infrared and longwave Dewar window was analyzed by finite element analysis and verified by experiments. The influence of the temperature of the Dewar window on the stray light and heat radiation of the cold screen was clarified. To reduce heat leakage between the lowtemperature window and the flange surface, the strength and heat insulation performance of the three types of shell support materials were compared. The effects of force, heat, and forceheat coupling on the design parameters of the Dewar window, such as the thickness and aperture margin, were analyzed. The deformation of the Dewar window was fitted using a Zernike polynomial, and the modulation transfer function (MTF) and wave aberration were used as evaluation indices to control window deformation of the largeaperture longwave infrared Dewar module. Subsequently, the influence of Dewar window deformation on the imaging quality of the infrared camera system under three conditions was analyzed. Results and DiscussionsWhen the window temperature decreases to 200 K, the window stray light and cold screen radiation are well suppressed (Fig. 3). When the target temperature is 220 K, the window radiation spurious ratio is less than 10%, satisfying the design requirements (Fig. 2). To reduce the heat leakage caused by the lowtemperature window and ensure reliable use, a titanium alloy shell with higher strength and lower heat conductivity is adopted. Under the same temperature difference (300 -250 K), the heat conduction of the titanium alloy shell is 278 mW; this is 49% and 43% lower than those of Kovar alloy (4J29) and stainless steel (304L), respectively (Fig. 4, Table 2). In mechanicalheat coupling, the window deformation caused by the heat load is dominant (Figs. 5 and 7), and increasing the window aperture is helpful to improve the window surface shape under mechanicalheat coupling (Fig. 8). When the thickness and aperture of the window are 4 mm and 8 mm, respectively, the influence of window deformation on 1410003 -9 研究论文第 50 卷第 14 期/2023 年 7 月/中国激光 the imaging quality can be neglecte...

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Design of Optical Window Thickness and Influence of its Deformation on Multi-Spectral Camera′s Optical Performance

Cited by 3 publications

References 0 publications

Semi-physical simulation of aerodynamic effect on quartz optical window in the high-altitude and high-speed environment

Semi-physical simulation of aerodynamic effect on quartz optical window in the high-altitude and high-speed environment

Design and Optical Performance Analysis of Large-Aperture Optical Windows for Structural Vibration Reduction

冷光学大口径长波红外探测器杜瓦窗口应用设计

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