Abstract

Currently available optically addressed spatial light modulators (OASLMs) are sensitive only to the visible and near infrared (< 1.1 μm) light [1]. For many applications OASLMs which are sensitive to infrared (IR) light at 1.55 μm are required or preferred. A common OASLM light-modulating material is liquid crystal (LC) which can be addressed by a thin film photosensor [2]. This scheme requires that the photosensor exhibits very low dark current to prevent the LC from switching on in the absence of write light, and high photosensitivity to switch the LC on in the presence of write light [3]. An InGaAs/InP photosensor fulfilling these requirements will allow the successful fabrication of an IR-sensitive OASLM. An OASLM incorporating such a photosensor has been previously reported but exhibited a poor contrast ratio due to the large InGaAs/InP dark current [4].

© 1997 Optical Society of America