HIGH-SPEED ANALOG ACHROMATIC INTENSITY MODULATOR

We report what is to our knowledge the first implementation of a broad band analog intensity modulator composed of two chiral smectic liquid- crystal half-wave retarders. A reflection-mode intensity modulator emp loying a single active device has also demonstrated achromatic transmi ssion. A quantitative theory for chromatic compensation is presented. By optimuim selection of liquid-crystal retardance and orientation, in tensity transmission is uniform throughout the visible. The chiral sme ctic liquid-crystal devices used in the implementation are capable of switching in less than 20 mus.