Terahertz electromagnetic wave radiation element and its manufacturing method

Abstract

The present invention improves the efficiency of conversion from a non-radiation two-dimensional electron plasmon wave into a radiation electromagnetic wave, and realizes a wide-band characteristic. A terahertz electromagnetic wave radiation element of the present invention comprises a semiinsulating semiconductor bulk layer, a two-dimensional electron layer formed directly above the semiconductor bulk layer by a semiconductor heterojunction structure, source and drain electrodes electrically connected to two opposed sides of the two-dimensional electron layer, a double gate electrode grating which is provided in the vicinity of and parallel to the upper surface of the two-dimensional electron layer and for which two different dc bias potentials can be alternately set, and a transparent metal mirror provided in contact with the lower surface of the semiconductor bulk layer, formed into a film shape, functioning as a reflecting mirror in the terahertz band, and being transparent in the light wave band. Two light waves are caused to enter from the lower surface of the transparent metal mirror, and two different dc bias potentials are alternately applied to the double gate electrode grating so as to periodically modulate the electron density of the two-dimensional electron layer in accordance with the configuration of the double gate electrode grating.