Terahertz intersubband electroluminescence from GaN/AlGaN quantum cascade laser structure on AlGaN template

We demonstrate terahertz (THz) electroluminescence (EL) from a GaN/AlGaN quantum cascade laser (QCL) structure fabricated on an AlGaN template. From investigations of a polarization - and a voltage-dependence of the EL from the THz-QCL, we proved conclusively intersubband nature of the EL peak.