Unveiling the Property of Radiation: Angular Synthetic Aperture for Omnidirectional Fourier Imaging System with Centimeter Field of View

We demonstrate a Fourier Imaging system with centimeter field of view(FOV), and 0.0042{\deg}angular resolution at C band, for the entire 180{\deg} radiation angular range. To pursue omnidirectional Fourier imaging without aberration, a technique called angular synthetic aperture is employed, by multi-perspective imaging and stitching. The effect of tilting-introduced virtual lens is pointed out and dealt with in our system. For the sake of limited sensor size and aberration spot size, Fourier imaging at each perspective is restricted to angle range smaller than 3{\deg}. The imaging system with a 4f demagnification component is prudently designed to magnify Fourier imaging, relieving the pressure of pixel size of sensor for high sampling rate, meanwhile guarantee the 1cm object FOV within 3{\deg}range. All the system is automatically controlled, which is crucial for applications such as online-optimization for optical phased array(OPA). As far as we know, this is the state-of-art omnidirectional Fourier imaging system as to field of view and resolution.