Terahertz detectors, spectrometers, and imagers based on low-dimensional electron systems

Abstract

Because the terahertz (THz) frequency region is located between the electronic and photonic bands, even basic components like detectors and sources have not been fully developed, compared to the other frequency regions. The THz wave also has the problem of low imaging resolution, which results from the two to three order of magnitude longer wavelength than that of visible light. This article reviews new types of THz sensing, spectroscopy and imaging device technologies by employing low-dimensional electron systems, such as a carbon nanotube (CNT) array, graphene, and a two-dimensional electron gas (2DEG) in a semiconductor heterostructure.