Abstract

The radiative decay of the grating-coupled two-dimensional (2D) plasmons in semiconductor quantum nanostructures is one of the promising candidates for tunable solid-state terahertz (THz) radiation sources. In spite of their potential, excitation/relaxation process of 2D plasmons has not been fully understood because of difficulties in performing spectroscopic analysis on weak THz radiation from such structures. In this work, the THz radiation from 2D plasmons in AIGaAs/GaAs single quantum wells (SQWs) has been investigated by time-resolved THz emission spectroscopy.¹ For the case of a δ-doped thin-barrier sample, up to fifth-order plasmon modes were clearly observed for the first time to our knowledge. The observed plasmon dispersion was in excellent agreement with the results of the full grating theory.² Furthermore, we investigated the effect of the excitation photon energy on the THz emission intensity.

© 1998 Optical Society of America