Antenna enhanced graphene THz emitter and detector

TL;DR

This paper demonstrates the first experimental graphene-based THz emitter and a highly sensitive detector, achieving significant performance improvements through antenna and lens enhancements, advancing practical graphene THz devices.

Contribution

It introduces the first experimental graphene THz emitter and a highly sensitive detector with performance enhancements using antenna and lens integration.

Findings

First observation of 1-3 THz radiation from graphene

Four orders of magnitude improvement in GFET detector performance

Significant non-thermal contribution to THz emission

Abstract

Recent intense electrical and optical studies of graphene have pushed the material to the forefront of optoelectronic research. Of particular interest is the few terahertz (THz) frequency regime where efficient light sources and highly sensitive detectors are very challenging to make. Here we present THz sources and detectors made with graphene field effect transistors (GFETs) enhanced by a double-patch antenna and an on-chip silicon lens. We report the first experimental observation of 1-3 THz radiation from graphene, as well as four orders of magnitude performance improvements in a GFET thermoelectric detector operating at ~2 THz. The quantitative analysis of the emitting power and its unusual charge density dependence indicate significant non-thermal contribution from the GFET. The polarization resolved detection measurements with different illumination geometries allow for detailed and quantitative analysis of various factors that contribute to the overall detector performance. Our experimental results represent a significant advance towards practically useful graphene THz devices.