Engineering transient hyperbolic metamaterials using InAsSb-based semiconductor

The authors demonstrate the ability to create an ultrafast hyperbolic momentum state using metallic InAsSb alloys embedded within dielectric GaSb and explore the possibility of transient modification of metamaterials to control the optical properties of photon emission. Properly engineered quantum well structures were grown by molecular beam epitaxy and Si-doped in order to convert the InAsSb layers from dielectric to metallic at infrared frequencies. The carrier excitation scheme of the engineered hyperbolic stacks was investigated in a variety of excitation levels using pump–probe measurements. The photo-excited carriers in the structure with a metal fraction of ∼0.5 showed a polarization dependent reflectivity change, which indicates a transient hyperbolic metamaterial state in the heterostructure induced by the pump laser.