Tunable optical filter using phase change materials for smart IR night vision applications

Abstract

In this paper we present a tunable filter using Ge₂Sb₂Se₄Te₁ (GSST) phase change material. The design principle of the filter is based on a metal-insulator-metal (MIM) cavity operating in the reflection mode. This is intended for night vision applications that utilize 850nm as the illumination source. The filter allows us to selectively reject the 850nm band in one state. This is illustrated through several daytime and nighttime imaging applications.