| 20110180733 | TERAHERTZ RADIATION DEVICE USING POLAR SEMICONDUCTOR MATERIALS AND METHOD OF GENERATING TERAHERTZ RADIATION - A method and device for generating terahertz radiation comprising a plurality of layers of polar crystal material operative to emit terahertz radiation; the plurality of layers comprising transport layers and divider layers, the plane of the layers being not parallel to the polar axis, the interface between the transport layers and divider layers forming boundaries at which the internal electric polarization terminates leading to charges accumulating at the boundaries, and creation of internal electric fields oriented along the polar axis; whereby when irradiated by a pulsed source of duration less than one picosecond, a time-varying and spatially nonuniform distribution of carriers is created in the growth direction of the polar crystal material thereby generating a first time-varying current due to diffusion of the carriers; the internal electric fields accelerating the carriers generated by the pulsed radiation source operating to produce a second time-varying current that is additive with the first time-varying current, thereby enhancing the generation of terahertz radiation. | 07-28-2011 |
