THz emission induced by optical beating in nanometer-length field-effect-transistors

TL;DR

This paper reports the experimental observation of terahertz emission in InGaAs transistors caused by plasma waves excited through optical beating, with resonances explained by transistor channel instabilities.

Contribution

It provides the first direct measurement of THz emission induced by optical beating in nanometer-scale FETs and explains the resonances via plasma wave instabilities.

Findings

Resonant THz emission observed at 0.3-0.5 THz range.

Emission resonances are stable and supported by numerical models.

Optical beating effectively excites plasma waves in the transistor channel.

Abstract

Experimental results of direct measurement of resonant monochromatic terahertz emission optically excited in InGaAs transistor channels are presented. The emission is attributed to two-dimensional plasma waves excited by photogeneration of electron-hole pairs in the channel at the frequency $f_0$ of the beating of two cw-laser sources. The presence of resonances for the radiation emission in the range of $f_0\pm 10$ GHz (with $f_0$ from 0.3 up to 0.5 THz) detected by a Si-bolometer is found. Numerical results support that such a high quality of the emission resonances can be explained by the approach of an instability in the transistor channel.