Researchers demonstrate cavity-enhanced THz photodetection using acoustic graphene plasmons

A research team lead by ICFO has demonstrated a cavity-enhanced terahertz (THz) photoresponse in a scalable monolayer graphene device, using acoustic graphene plasmons (AGPs) to boost detection efficiency while maintaining a practical fabrication approach.

Terahertz radiation, spanning wavelengths from 15 to 1000 μm (0.3 to 20 THz), is gaining attention for applications such as biomedical imaging, chemical sensing, security screening, and high-speed wireless communications. However, current THz detectors typically face trade-offs between speed, sensitivity, noise, and operating conditions, making it difficult to achieve high performance across all parameters. In this work, the researchers designed a device based on chemical-vapor-deposited (CVD) monolayer graphene integrated with a dipole antenna. This antenna concentrates incoming THz radiation (1.83 to 2.52 THz), acts as a pair of gate electrodes, and launches AGPs – collective oscillations of electrons – into the graphene channel. These plasmons reflect within the device and form standing waves, effectively creating a Fabry–Pérot-type cavity.

Read More Graphene-Info – Graphene industry portal