Research On Key Technologies Of Spaceborne Small-size Interference Imaging Camera

The spaceborne light small interference imaging camera is a new type of computational imaging camera realized by microlens integrated aperture technology and photon integrated circuit technology.Interferometric imaging cameras can break through the limitations of traditional camera caliber and greatly reduce the overall size of camera.Therefore,it is expected that this kind of space-borne camera will be light,small,and chip-based,and it will play an important role in high-resolution reconnaissance and space detection.The main work of this paper is the key technology research of spaceborne small-size high-resolution camera which is based on the principle of interference imaging.The key technology research includes working principle of key components,research of the whole machine workflow,mechanism of system imaging influencing factors,and a new microlens array layout scheme which can effectively improve image quality.The main content of paper consists of the following aspects:First,the theoretical basis of interference imaging camera and the synthetic aperture imaging technique are introduced.Based on the investigation of the SPIDER camera,this paper analyzed the overall structure and introduced the key components used in photonic integrated circuit include arrayed waveguide grating,90° optical hybrids and balanced four-quadrature detector.Then the overall workflow was given.Then,optical waveguide coupling efficiency model is established.This model has been used to analyze the relationship between coupling efficiency with optical system's F/# and FOV.After that,the preliminary parameters of interference imaging camera can be determined.Based on that,this paper established theoretical imaging model of this interference imaging camera and performed numerical simulation.The mechanism of imaging affecting factors were explained including baseline matching method,microlens duty cycle and sampling interval.And the simulation results confirmed the influential impact of these factors.Then this paper has list performance parameters of these two kind of camera.Finally,a new microlens array layout scheme,the "wheel" layout is proposed that not only is feasible to realize but also can effectively improve the system image quality.By comparing the point source response of the "wheel" layout,the original layout and the cryptographic primary layout,this paper confirmed that system's limit resolution capability under the "wheel" layout is significantly higher than the others.The image quality of reconstructed images obtained under the three layout methods was evaluated by the full reference image quality evaluation function.The results show that system's imaging quality is effectively improved under the "wheel" layout.The simplicity and effectiveness of the new layout scheme is verified from two aspects of system structure parameters and imaging quality.