Challenges for intersubband terahertz emitters and possible solutions through advanced numerical simulations

This talk starts with an overview of present challenges for TERA-MIR devices and the state of the art of the most promising device for this range: the quantum cascade laser (QCL). The need for advanced quantum statistical mechanics, many particle and nonequilibrium Physics to describe these devices will be explained and results of our leading edge simulator will be presented. In the last part of the talk progress on intersubband lasing without inversion will be discussed, since those designs can mitigate some of the most crucial problems faced by THz QCLs. In particular the influence of increasing dephasing on the k-space filtering mechanism will be discussed.