Design of a Foveated Imaging System Based on Liquid Crystal Microlens Array

摘要

We propose a foveated imaging system (FIS) implementing by effectively correcting wavefront aberration, which mimics the human visual system to obtain a high resolution image for the regions of interest (ROI) while keeping a wide field of view (FOV). It is flexibly tuning the variation of the refractive index of liquid-crystal (LC) materials through adding variable AC voltage signals. A novel liquid-crystal microlens array (LCMLA) with three concentric ring-electrodes are presented, where three different AC voltage signals can be applied to corresponding ring-electrodes. There are three hexagon arrangement patterned electrode arrays with different diameters (equivalent to 98μm, 112μm and 140|im from the center to the periphery) in the concentric circles. The diameter of the MLA in the central field is the smallest, where the spatial resolution may be the highest. If appropriate AC voltage signals are added, the wavefront aberration of the incident light of ROI could be well adjusted. An experiment is developed to validate the performance of the FIS using LCMLA. The example images show that the proposed FIS can obtain local high resolution image of the ROI by dynamically controlling AC voltage signals and a total low resolution image over a wide FOV.