Inter-subband plasmon-emission-based THz Lasers

We have proposed stimulated generation of plasmons (plasma instabilities) as a novel way to generate THz radiation from low-dimensional semiconductor systems. The microcharge oscillations of such plasmons become the source of electromagnetic radiation in the THz range. This plasma-instability-based concept offers distinct advantages as it relies on a collective phenomenon, which is less susceptible to disruption due to higher temperatures and various scattering effects. Also, since the plasmons are created internally and form a (coherent) collective mode of the electron gas itself, there is no need for an external feedback mechanism. A self-consistent calculational scheme shows the feasibility of plasma instabilities in appropriately designed quantum well structures.