In recent years, infrared (IR) spatial light modulators (SLM) have found applications in areas such as scene simulation and dynamic spatial frequency filtering. To help meet these requirements, we have developed two novel methods of SLM fabrication. Both SLM designs deposit a vanadium dioxide (VO₂) thin film on a thermal array. VO₂ films exhibit a temperature dependent hysteresis about their transition from dielectric to conductor. Accompanied with this transition is a change from a state of low to high reflectivity in the 3 - 5 micrometers band. Our two SLM designs exploit this temperature dependent hysteresis through the use of thermal arrays. The first SLM design deposits the VO₂ thin film on a planar diode array. Each diode constitutes a `pixel' of the SLM. Power provided to a diode permits accurate thermal control about the film's hysteresis. Initial biasing of the diode array is required to the base of the VO₂'s hysteresis curve. The second SLM design deposits VO₂ on a thermoelectric array. These pixels have the ability to both heat and cool the VO₂ film, thereby allowing the array to be operated in a bistable mode. Bistable operation requires external biasing to the center of the VO₂'s hysteresis curve.

Date Published: 31 August 1993
PDF: 8 pages
Proc. SPIE 1969, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing IV, (31 August 1993); doi: 10.1117/12.154728

Published in SPIE Proceedings Vol. 1969:
Infrared Imaging Systems: Design, Analysis, Modeling, and Testing IV
Gerald C. Holst, Editor(s)