Radiation sensor with synchronous reset

摘要

This invention consists of a radiation sensor with a thermal cycling and synchronous readout scheme. It is intended for use with pyro-optical materials which exhibit a phase transition that is hysteric. A preferred material is vanadium oxide which has a semiconductor-metal phase transition typically at 68 deg C. and a hysteresis of a few degrees C. depending on material processing. The temperature of the pyro-optical film is cycled in synchronization with readout electronics to achieve a reset reference for the readout once each repetitive cycle. When the thermal cycle is divided into two regions, a reference and a biased frame are obtained. The readout electronics compare the reference frame the biased frame to obtain a desired difference which is an unbiased frame.