Analytical and computer models of terahertz HEMT photomixer

We develop device models of a terahertz (THz) photomixer based on a high-electron mobility transistor (HEMT) structure utilizing the excitation of electron plasma oscillations in the HEMT channel by the electrons and holes photogenerated by optical signals. We use hydrodynamic equations both for electrons in the channel and for photoelectrons and photoholes in the absorption layer, or hydrodynamic equations for electrons in the channel combined with a kinetic description of the photogenerated carriers, and the Poisson equation for the self-consistent electric field. The models are used for an analytical as well as numerical (based on an ensemble Monte Carlo particle technique) analysis of the HEMT-photomixer operation in the THz frequency range.