High Sensitivity Terahertz Detection through Large-Area Plasmonic Nano-Antenna Arrays

TL;DR

This paper introduces a broadband terahertz detector using large-area plasmonic nano-antenna arrays that achieve high sensitivity and robustness, overcoming previous bandwidth limitations.

Contribution

The paper presents a novel large-area device geometry for plasmonic photoconductive antennas that enhances bandwidth and interaction with terahertz and optical beams.

Findings

Achieved broadband terahertz detection with SNR up to 107 dB.

Demonstrated robustness against beam misalignments.

Enabled high-sensitivity detection in terahertz imaging.

Abstract

Plasmonic photoconductive antennas have great promise for increasing responsivity and detection sensitivity of conventional photoconductive detectors in time-domain terahertz imaging and spectroscopy systems. However, operation bandwidth of previously demonstrated plasmonic photoconductive antennas has been limited by bandwidth constraints of their antennas and photoconductor parasitics. Here, we present a powerful technique for realizing broadband terahertz detectors through large-area plasmonic photoconductive nano-antenna arrays. A key novelty that makes the presented terahertz detector superior to the state-of-the art is a specific large-area device geometry that offers a strong interaction between the incident terahertz beam and optical pump at the nanoscale, while maintaining a broad operation bandwidth. The large device active area allows robust operation against optical and terahertz beam misalignments. We demonstrate broadband terahertz detection with signal-to-noise ratio levels as high as 107 dB.