# Electro-Optical Imaging Technology Based on Microlens Array and Fiber Interferometer
## 1 Introduction  
Without considering the influence of astronomical observation, the imaging resolution of traditional optical telescopes based on the principle of refraction can only be improved by increasing the aperture. However, the manufacture of large-aperture optical telescopes is an enormously expensive undertaking and also requires significant technical support. To overcome the limitations of the image resolution by the size of a single aperture, many novel optical telescopes based on interference imaging have been designed in recent years. For example, the Cambridge Optical Aperture Synthesis Telescope (COAST) has achieved imaging [1], and [PERSON] et al. completed the Naval Prototype Optical Interferometer (NPOI) optical synthetic aperture telescope array and successfully performed observation and image reconstruction [2; 3]. In addition, several cutting-edge electro-optical imaging systems have been designed to greatly reduce the volume and weight of traditional optical telescopes, like the geosynchronous earth orbit (GEO) telescopes, which are an interferometric imaging system with arrays of telescopes. Other approaches include that of combining observations from a separated-element interferometer with interferometric data obtained by optical masking of a single-dish telescope [4]. The most representative cutting-edge electro-optical imaging system is the Segmented Planar Imaging Detector for Electro-Optical Reconnaissance (SPIDER), which has been developed by Lockheed Martin and can realize a 10\(\times\) to 100\(\times\) reduction in size and weight by replacing the traditional lens stacks with silicon chip photonic integrated circuits (PICs) [5; 6; 7].  
Most of the above telescopes are based on astronomical light interference and optical synthetic aperture imaging [8; 9; 10]. The optical synthetic aperture imaging technique is to improve the resolutionof single aperture imaging by measuring the interference result between the observation plane aperture pairs (ie, the spectral value of the observed target). In this technique, the interference fringe of a pair of apertures corresponds to a spectral value of the target, so the complete spectrum of the target is often obtained by changing the relative position between the pairs of apertures or increasing the number of apertures. As we all know, the optical fiber optical path has the characteristics of softness, long transmission distance and strong anti-interference. The use of optical fiber to realize light interference is an important application of interference phenomenon, and will greatly reduce the working distance of the interference system [11; 12].  
To reduce the volume and weight of traditional optical telescopes effectively, we propose in this paper a cutting-edge electro-optical imaging technique based on a microlens array and fiber interference. In this technique, the light from a scene was first collected by the microlens array and then coupled into the fiber interferometer. Note that each microlens pair was coupled by fiber to form an interference baseline, which had a significant effect on the imaging resolution. Thus, through the optimal microlens arrangement and pairing method, we could complete spectrum sampling of the scene and generate high-resolution images. To establish the optical simulation model, the imaging principle based on the partial coherence theory was first studied first. Then, a complex rectangular sub-aperture arrangement and a symmetrical baseline pairing method were proposed to improve the imaging resolution and quality further. Moreover, we investigated the impact of spatial frequency distribution (\(u\), \(v\)) on imaging quality, including the resolution, field of view, and depth of focus of the imaging system. The simulation results provide a valid reference for the design of the actual system.