Hydrogenated amorphous-silicon photosensor for optically addressed high-speed spatial light modulator

A high-speed, optically addressed spatial light modulator (OASLM) which incorporates a hydrogenated amorphous silicon (a-Si:H) photosensor and a ferroelectric liquid-crystal (FLC) modulator is discussed. The device operates with an applied square-wave voltage such that read and write operations occur under reverse bias, while the erase operation occurs under forward bias. The OASLM exhibits a response time of 155 mu s and a spatial resolution of >33 1p/mm. The capacitance and resistance of both the a-Si:H and FLC have been measured and are shown to influence the response of the device strongly. >