Closing the Gap: Plasma Wave Electronic Terahertz Detectors

The terahertz portion of the electromagnetic spectrum is experiencing a substantial growth in interest, with new applications in security, medicine and communications, among others, emerging at a rapid pace. Limitations in source power, the reported "terahertz gap," place stringent requirements upon THz detector device performance in terms of responsivity, sensitivity and response speed. In this paper, we review the present state-of-the-art in terahertz sources and detectors, and discuss in some detail the operation of an emerging class of plasma wave terahertz devices.