Tune in to terahertz

摘要

From a human point of view, the terahertz frequencies are a curiously barren region of the electromagnetic spectrum. They lie, unexploited, between microwaves at long wavelengths and infra-red at short. They are neglected because no one has developed a convenient source of terahertz radiation. Not yet, anyway. But a laser unveiled by Alessandro Tredicucci of the Scuola Normale Superiore in Pisa, Italy, at the recent International Conference on the Physics of Semiconductors, in Edinburgh, lights the way to the future.