High-Power photoconductive terahertz source enabled by three-dimensional light confinement

Abstract

We present a novel photoconductive terahertz source that can generate high power and broadband terahertz radiation with high optical-to-terahertz conversion efficiency. The high optical-to-terahertz conversion efficiency is achieved by confining the optical pump photons very tightly around the radiating elements of the photoconductive source. A distributed Bragg reflector and plasmonic nanostructures are used for three-dimensional confinement of light. We experimentally demonstrate a record-high terahertz radiation power of 4 mW over a 0.1–4 THz frequency range.