Optical element, and optical device and terahertz time-domain spectroscopic apparatus including the same

摘要

An optical element includes a semiconductor layer having an energy band gap larger than a photon energy of light, and a plurality of electrodes in electrical contact with the semiconductor layer. At least one of the electrodes forms a Schottky junction between the electrode and the semiconductor layer; the Schottky junction has a barrier height smaller than the photon energy of the light. At least part of a junction surface between the electrode that forms the Schottky junction and the semiconductor layer includes a light irradiation surface arranged to be irradiated with the light from a surface of the semiconductor layer without the electrodes, and a portion of a coupling structure arranged to be coupled to a terahertz wave that is generated or detected through the irradiation with the light.

主权项

1. An optical device arranged to generate or detect a terahertz wave, the optical device comprising:
a laser light source configured to output light; an optical element configured to generate or detect the terahertz wave when the optical element is irradiated with the light; and an optical unit configured to direct the light from the laser light source to the optical element, wherein the optical element includes: a semiconductor layer; and a plurality of electrodes formed in electrical contact with the semiconductor layer and including an antenna configured to couple the terahertz wave and a space, wherein at least one of the electrodes forms a Schottky junction between the one electrode and the semiconductor layer; wherein the laser light source outputs the light whose photon energy is larger than a barrier height of the Schottky junction and smaller than an energy band gap of the semiconductor layer; and wherein the optical unit is arranged to irradiate the Schottky junction with the light through a surface of the semiconductor layer without the electrodes.