Research On Ultra-thin High-resolution Planar Imaging Method Based On Interference Theory

The ultra-thin high-resolution flat-panel imaging method is a novel imaging idea based on the Van-Cittert Zernike theorem and photonic integrated circuit technology,which aims to significantly reduce the size,weight and power of the imaging system,and o btain high resolution images.Each lenslet couples object light into a single mode waveguide,and arrayed waveguide gratings are used to disperse broadband light into different spectral channels,which is routed to an input port of a balanced four-quadrature detector that yields an estimate of the object complex visibility for the corresponding interferometer baseline,the calculation by these waveguide devices replace the propagation of light in free space in traditional optoelectronic imaging systems,this method can avoid the manufacture,polishing,and calibration of large-scale optical systems to significantly reduce development and manufacturing cycles.Based on the principle of optical inter ference imaging,image reconstruction process and photonic integrated circuit architecture,this paper analyzes the influencing factors of imaging quality in ultra-thin high-resolution flat panel imaging system.Firstly,this paper starts from the coherence of light and explains the imaging principle and image reconstruction process of the ultra-thin high resolution flat panel imaging method combining with the Van-Cittert Zernike theorem.The relationship between the spatial frequency sampling point and the baseline vector are clearly defined,the relationship between the amplitude of complex coherence factor and the visibility of stripe are clearly defined,too.Based on the signal transmission process in the imaging system,the system imaging process was analyzed.The function of the waveguide device in the photonic integrated circuit was described in conjunction with the imaging system's photonic integrated circuit architecture,the basic theory of arrayed waveguide gratings and the influence of the number of channels on the imaging quality are highlighted.Secondly,this paper introduces the U-V coverage technology and the method to obtain U-V spectrograms of ultra-thin high-resolution flat-panel imaging system.The influencing factors of constructing high-quality U-V spectrograms are studied,including complex coherence factors and U-V spatial frequency coverage.Based on the interference principle of light,the effect of the characteristics of the light source itself and arrayed waveguide grating on the visibility of the fringes were analyzed;the effects of the lens array distribution and baseline pairing method,the sub-lens duty cycle,the sampling interval,and the number of channels of the arrayed waveguide grating on U-V coverage were studied.This will lay the foundation for analyzing the influence of these factors on the imaging quality of the system.Then,according to the imaging principle of the ultra-thin high-resolution flat panel imaging method,the simulation of the system reconstruction imaging process is realized,the spatial frequency points are used to take sample for ideal mutual intensity spectrum to get the actual detected mutual intensity spectrum.The inverse two-dimensional intensity distribution of the target is obtained by inverse Fourier transform of the actual intensity spectrum.Based on this,the single variable principle was used to change the baseline pairing method,the longest baseline length,the sub-lens duty cycle,the sampling interval and the number of arrayed waveguide grating channels in order,and analyzed the influence of these factors on the imaging quality of the system.Finally,based on the basic principle of the ultra-thin high-resolution flat panel imaging method and the study of the related factors of constructing high-quality UV spectrograms,the concept is proposed to improve the performance of the ultra-thin high resolution flat panel imaging system.The imaging system using the compensated lens array model was studied.The image reconstruction of the imaging system was simulated and the influence of low frequency padding on the imaging quality was analyzed.