Abstract

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 al an AlGaAs/GaAs heterojunction.¹ The surface of the sample is covered with a grating-coupler, allowing the coupling of the plasmons to the THz-field. The 100-fs pulses from a Ti:sapphire laser strikes the sample under an angle of 45°. The emitted THz radiation is delected by time-domain THz-emission spectroscopy, a technique allowing the selective measurement of coherent (i.e., phase-synchronous) FIR radiation phenomena in the frequency range from 0-4 THz.

© 1996 IEEE