As we continue to push the limits of space exploration and travel, demands on next-generation space systems will increase while being constrained by lean SWaP-C (size, weight, power, and cost) budgets. Realizing subsystems that meet such performance demands requires novel photonic material platforms. Chalcogenide phase-change materials (PCMs) such as GeSbTe, GeSbSeTe, and SbTe demonstrate great potential to fulfill these needs.

Chalcogenide PCMs have the ability to repeatedly switch between two distinct, nonvolatile solid phases: crystalline and amorphous, where the crystalline phase demonstrates high conductivity and reflectivity and the amorphous phase demonstrates low conductivity and reflectivity. There is widespread use of chalcogenide PCMs in commercial nonvolatile memory devices. However, investigations into its potential photonic applications—such as tunable filters, active metaoptics, and switchable fiber-optics—picked up rapidly in the past decade.^a