Research On Quality Characterization And Improvement Of Planar Integrated Optical Interference Imaging

Planar integrated optical interference imaging system is a new type of detection imaging system based on optical integrated aperture technology and photonic integrated circuits.Compared with the traditional large-aperture optical imaging system,it has the following advantages:(1)The resolution is determined by the distance between the sub-apertures,rather than the clear aperture size of the traditional imaging system,which reduces the system's quality,volume and power consumption.(2)The coupling,transmission and calculation of signal light by optical elements in photonic integrated circuits have replaced the free propagation method in traditional optical systems,reducing the size of the system;(3)With the maturity of photonic integrated circuit technology,the interference detection system is easier to achieve mass production.Planar integrated optical interference imaging technology can provide an option for the design of optical detection systems with high resolution,light weight,small size and low power consumption.In the future,it has huge development potential and application space in high-resolution imaging scenarios such as military reconnaissance,space early warning,astronomical observation and remote sensing imaging.The main research work of this paper is as follows:(1)This paper introduces the signal transmission process of the planar integrated optical interference imaging system,and studies the system resolution,imaging field of view,coupling efficiency,sub-aperture collected energy,and spatial frequency coverage capability.The point spread function and optical transfer function model of the pupil surface of the system were established,and the imaging effects of two working modes of interference detection reconstruction imaging and direct interference imaging were simulated.The results show that in the mechanism of interference detection reconstruction imaging,the system Spectral multiplexing and coherent computing improve its spatial frequency sampling capability,and its imaging effect is better than the direct interference imaging mechanism.(2)From the perspective of spatial spectrum coverage,this paper analyzes the factors that limit the imaging quality of the system,and studies the methods to improve the spectral coverage of the system in the radial and axial directions.We first propose a continuous frequency coverage condition in the radial direction.This condition can be used as areference principle in the design of the baseline length to achieve radial continuous frequency coverage on the interference arm,and improve the ability of collecting high-frequency information in the system.Then this paper analyzes the influence of channel wavelength interval on the imaging quality of the system,and designs arrayed waveguide grating(AWG))in the near-infrared and visible light bands with small spacing and low loss to enhance the system's interference sensitivity.In terms of improving the axial spectral coverage of the system,based on the idea of time-division multiplexing,this paper proposes a dual-arm large-bore rotary sampling working method.The design of the dual-arm achieves radial continuous frequency coverage increased the frequency coverage capability of the system in the axial direction,thereby improving the imaging quality of the system.(3)According to the imaging principle of the planar integrated optical interference imaging system,we simulate the imaging reconstruction process of a space-based remote sensing system.The longest baseline is 273 mm,the angular resolution is 0.5 ",and the maximum spatial frequency is 682.5 cycles / mrad.The imaging effects with 37 arms and 73 arms are simulated.Compared with the traditional imaging process,the advantages and disadvantages of the planar integrated optical interference imaging system are analyzed.(4)From the perspective of data reconstruction,this paper studies the problem of system image reconstruction based on the compressed sensing theory,and discusses the improvement of imaging quality by various reconstruction algorithms with different penalty terms.The results show that the reconstruction effects are arranged in order from good to bad : TV > BPDN > FOCUSS ?iFFT2.