High power subterahertz electromagnetic wave radiation from GaN photoconductive switch

Abstract

The authors present apparently the observation of subterahertz electromagnetic wave emission from GaN based large aperture photoconductive switches (LA-PCSWs) excited by ultraviolet femtosecond laser pulses. The photoconductive layer of the GaN LA-PCSW is doped with carbon giving rise to a resistivity as high as 60MΩcm. The absolute energy of the emitted radiation pulses is measured to be 93.3pJ/pulse under 500V bias voltage. The Fourier spectrum of the measured pulse by the time-domain-spectroscopy shows the main components lie in 0.1–0.2THz regime.