Tunable THz radiation from 3-D topological insulator

Terahertz (THz) waves, located between the millimeter and far-infrared frequency ranges, are an electromagnetic frequency band that is as-yet incompletely recognized and understood. Xiaojun Wu of Beihang University leads a group of researchers actively seeking ways to understand, generate, and control THz radiation. Wu notes that THz waves have great potential for expanding real applications—from imaging to information encryption—but the development of THz science and technology has been hindered by a lack of sufficiently efficient sources.