Research On Full-Chain Characterization And Improvement Of Miniature Interferometric Integrated Optical Imaging Quality

The development of ultra-thin,ultra-light and high-resolution optical telescope is of great significance to the development of astronomical observation and space surveillance optical telescope imaging.In recent years,the concept of miniature interferometric integrated optical imaging based on photonics integrated circuits(PICs)provides a new way to develop ultra-thin planar and ultra-high resolution telescope system.Miniature interferometric integrated optical imaging is an optical synthetic aperture interferometric imaging technology based on PICs essentially.It is completely different from the photoelectric telescope imaging system based on the principle of refraction and reflection,which can avoid the cumbersome manufacturing process through the semiconductor fabrication process,and greatly reduce the volume,weight and power consumption of the system.Focusing on the development of new generation optical remote imaging system,this paper analyzes the degradation mechanism of the optical field control physical effects of integrated optical functional devices on the image quality of miniature interferometric integrated optical imaging system.And the key technical problems such as the scene light field radiation multidimensional conversion modeling,optimization design of functional devices and image quality promotion based on optical design/computational reconstruction et al are studied deeply.Meanwhile,a miniature interferometric integrated optical imaging experimental with controllable light field parameters is built and the light field image data is obtained.Research results will provide theoretical and technical supports for the development of a highperformance miniature interferometric integrated optical imaging system,and pave a new way for the revolutionary progress in space based Electro-Optical image reconnaissance and surveillance system.The main research work is as follows:(1)For engineering application,aiming at the problems of poor contrast,loss of sampling information and low resolution in the reconstructed image,the degradation mechanism of the optical field control physical effects of integrated optical functional devices(lens arrays,waveguide arrays,arrayed waveguide gratings,phase shifters and balanced quadrature detectors)on the image quality of miniature interferometric integrated optical imaging system is deeply studied.The influences of the engineering error of integrated optical functional devices on the imaging quality are analyzed.Meanwhile,the error control range of key functional devices is determined.The research results lay a theoretical foundation for the engineering application of miniature interferometric integrated optical imaging system.(2)Due to the lack of light field conversion model and characterization model for miniature interferometric integrated optical imaging,based on the end-to-end light field conversion and characterization of miniature interferometric integrated optical imaging system,this paper analyzes scene light field radiation multi-dimensional transferring,converting,and coupling mechanisms.The theoretical model of multi-dimensional light field(spatial,radiation and spectral dimensions)transfer and conversion of scene radiation field through miniature interferometric integrated optical imaging system is established,which lays the foundation for the characterization of the imaging quality and U-V spatial spectrum accurate coverage of the full-chain miniature interferometric integrated optical imaging system.(3)Based on the miniature interferometric integrated optical imaging quality characterization model and the light field conversion model,in order to solve the problem of poor imaging quality due to insufficient medium and low frequency sampling information in the miniature interferometric integrated optical imaging system,a hierarchical multistage sampling lens array is designed in this paper.By increasing medium and low frequency information acquisition in different directions to achieve the accurate coverage of U-V spatial spectrum(two-dimensional spatial spectrum).Meanwhile,based on the hierarchical multistage sampling lens array,reasonable suggestions are put forward for the selection of key system parameters of the miniature interference integrated optical imaging system.Among them,the optimal wavelength spacing of AWG is 10 nm,and the fill factor tolerance error of the hierarchical multistage sampling lens array is 5%.(4)Considering the different aperture sizes of lens array,a non-uniform multistage sampling lens array is designed in this paper.Meanwhile,the radius calculation model of non-uniform multistage sampling lens array is established.And the parameters of the waveguide connected with the lens array are calculated.The research results can provide a theoretical basis for the optimal design and manufacturing of miniature interferometric integrated optical imaging system.(5)Miniature interferometric integrated optical imaging system can be applied to different scenes.An internal and external iterative optimization algorithm is designed to reconstruct the image for astronomical interferometric imaging.At the optimal initial threshold,the PSNR of the system imaging is improved by at least 3d B,and the SSIM is improved by at least 0.6.The minimum total variation method is used to improve the image quality for ground interference imaging.The PSNR of the system imaging is improved by at least 5d B,and the SSIM is improved by at least 0.14.The system imaging results with different number of interference arms and different wavelength spacing of arrayed waveguide grating are reconstructed to verify the feasibility of the reconstruction algorithm in different applications.(6)A verification experiment of miniature interference integrated optical imaging was built.The rationality of miniature interferometric integrated optical imaging theory is verified by sampling and reconstructing a single frequency sinusoidal amplitude grating.At the same time,the simple target imaging experiment is discussed and analyzed,which provides a practical basis for the improvement of the experimental imaging.