Helicity sensitive terahertz radiation detection by field effect transistors

TL;DR

This paper demonstrates a highly sensitive, room-temperature terahertz polarization detector using GaAs/AlGaAs FETs, leveraging plasma oscillation interference to detect light helicity and linear polarization with fast response.

Contribution

It introduces a novel terahertz polarization detection method based on plasma oscillations in FETs, achieving significantly higher sensitivity than previous approaches.

Findings

Helicity dependent photoresponse exceeds previous reports by several orders of magnitude.

The device can detect all polarization parameters of terahertz radiation.

Response time is faster than 1 nanosecond.

Abstract

Terahertz light helicity sensitive photoresponse in GaAs/AlGaAs high electron mobility transistors. The helicity dependent detection mechanism is interpreted as an interference of plasma oscillations in the channel of the field-effect-transistors (generalized Dyakonov-Shur model). The observed helicity dependent photoresponse is by several orders of magnitude higher than any earlier reported one. Also linear polarization sensitive photoresponse was registered by the same transistors. The results provide the basis for a new sensitive, all-electric, room-temperature and fast (better than 1 ns) characterisation of all polarization parameters (Stokes parameters) of terahertz radiation. It paves the way towards terahertz ellipsometry and polarization sensitive imaging based on plasma effects in field-effect-transistors.