Trends in the Research of Modern Terahertz Detectors: Plasmon Detectors

Terahertz (THz) wave detectors include Golay cells, bolometers, pyroelectric detectors, superconductor tunnel junction detectors (STJs), and Schottky-barrier diodes (SBDs). Of these, most (except STJs and SBDs) are of the thermoelectric type; they are highly sensitive, but the response speed is low. On the other hand, in SBDs operating at room temperature, the response is fast, but the sensitivity is rather low at high frequencies; this is due to the carrier transit-time effect. Therefore, a nonlinearity of the two-dimensional plasmons, quanta of collective excitation of electronic charge density waves, has attracted attention as a mechanism of fast and sensitive THz-wave rectification and detection. In this paper, technological trends in the research of modern THz detectors are reviewed, with an emphasis on plasmon-type detectors.