Switchable Infrared Filter Enabled by Phase Change Materials

There is a Department of Defense (DoD) need for improved hyperspectral imaging in the mid-infrared and longwave infrared for improved situational awareness, target identification, standoff detection, and remote sensing. Current state-of-the- art tunable filters are single function, have limited optical throughput (~50%), are bulky (~ 100cm3), are slow (~40ms switching time), and have narrow bandwidth. Physical Sciences Inc. (PSI) in collaboration with Purdue University proposes to develop Switchable Metamaterial Infra-Red Filters (SMIRFs) based on novel phase change materials incorporated into dielectric metamaterials. Cascading the filters in series will allow for full spectral coverage of the mid-infrared and longwave infrared bands with multiple filters able to be active at once. Rapid switching of optical filters such a compact footprint will enable a new generation of hyperspectral imaging applications.