Tailoring GaAs THz radiative properties with plasmons and surface phonon-polaritons

Absorption of visible and infrared radiation by gratings due to the resonant excitation of surface waves is a well known phenomenon. In this paper, we study resonant absorption of terahertz (THz) radiation due to either excitation of surface phonon polaritons on GaAs or to mixed surface plasmon-phonon polaritons respectively on n-doped GaAs. Such surface waves exist around 8.5 THz (35 microns).