Radiation sources

摘要

A radiation source for the generation of terahertz electromagnetic radiation comprises a solid state device for the collective propagation of a plurality of charge carriers (electrons or holes) as a substantially two-dimensional charge carrier gas with a coupling arrangement to transfer energy from the two-dimensional charge-carrier gas to a tuning device positioned adjacent to said solid state structure and a further coupling arrangement to extract said terahertz radiation from the tuning device. The invention also includes measuring and communications systems incorporating such radiation sources.