Abstract

Thin films of phase transition materials offer high-resolution 2-D formats for switching, recording, and processing optical signals. In most instances, a reversible, physical transformation is accompanied by large changes in both electric and optical properties. Examples cited include organics, rare-earth monochalcogenides, and vanadium dioxide. The external driving or control mechanism for vanadium dioxide is temperature; near 67°C the material changes from semiconducting to metallic behavior. Moreover, injection of energy (~15 mJ/cm²) into a small portion of the film causes the transition to occur only in that local region. The resulting local change may be either removed (dynamic operation) or stored indefinitely (memory operation). These options are possible because the material exhibits hysteresis, i.e., the curve describing the state of the film vs temperature is double valued in the transition region. A number of application concepts based on these unusual film properties are discussed.

© 1985 Optical Society of America