Method for improving performance of IR focal plane array using microlens array

An experiment which a diffractive microlens array on germanium is used for enhancing the fill factor of infrared focal plane array has been described in this paper. In order to achieve higher effective fill factor, the diffractive efficiency of each microlens and the transmissivity of the final element must be emphasized. The fabrication and the anti-reflection film evaporation for the diffractive microlens array have been studied. Based on a precise mechanics we have designed, a coupling experiment has been done and the main performance has been discussed. The fill factor of 80% is expected to be reached for the detector with original fill factor of 25%.