Polymer dispersed liquid crystal thin films for optical processing

A shape-controlled bistable hysteresis is observed for thin polymer dispersed liquid crystal films when inserted in feedback systems where the applied voltage depends on the intensity of the light transmitted by the film. A control of the hysteresis width is possible by acting on the parameters of the feedback circuit. The possibility of obtaining bistable regions of different width can be very useful in view of the application of PDLC as optic memory elements or binary data transmission devices. An investigation on the use of these films as optical switches for fiber interconnects is also performed and the preliminary results are reported. Technical improvements are suggested in order to increase the on/off contrast ratio of the switching behavior.