Cavity length dependence of a metasurface quantum-cascade laser with electrically switchable polarization

Abstract

Polarization switchable terahertz quantum-cascade lasers are candidate sources for polarimetric terahertz imaging and sensing as their output polarization can be switched electrically without moving parts. We report on the importance of the external cavity on the spectral properties and polarization purity for a metasurface quantum-cascade VECSEL.