Emission of THz radiation from optically excited coherent plasmons in a two-dimensional electron gas

Summary form only given. The radiative decay of grating-coupled plasmons in a two-dimensional (2D) electron gas in semiconductor heterostructures is an interesting candidate for a solid-state terahertz (THz) radiation source. We present the first observation of the emission of submillimeter radiation from optically excited coherent two-dimensional plasma oscillations at an AlGaAs-GaAs heterojunction. The surface of the sample is covered with a grating coupler, allowing the coupling of the plasmons to the THz field.