Phase-change band-pass filters for multispectral imaging

This is the author accepted manuscript. The final version is available from SPIE via the DOI in this recordPhase-change materials (PCMs) provide a route to adding dynamic tunability and reconfigurability to many types of photonic devices by changing the phase-state of the PCM itself. In this work we discuss the use of the phase-change alloy GeSbTe (GST) in the design of dynamically tunable filters operating in the infrared. GST is used to manipulate the extraordinary optical transmission of a periodic hole-array in a metallic layer, so creating ultra-thin, tunable band-pass filters. We discuss the use of such filters for multispectral imaging, suggest some approaches to overcome various practical challenges, and, finally, show that through the use of appropriate post processing algorithms this tunable filter could provide a cheap, ultra-thin, real-time, and relatively high performance multispectral imaging device.CDW acknowledges funding via the US Naval Research Laboratories ONRG programme (#N62909-16-1-2174) and the EPSRC ChAMP and WAFT grants (EP/M015130/1 and EP/M015173/1). LT acknowledges funding via the EPSRC CDT in Metamaterials (EP/L015331/1) and via QinetiQ PL