Patent ID: 8433170
Filing Date: 2013-04-30
Classification: B82Y,G02B,G02F,H01L

Abstract:
1. A system for controlling Terahertz (THz) radiation in a parallel plate waveguide (PPWG), comprising: a THz PPWG comprising parallel first and second electrically conducting layers and a semiconductor layer disposed between the first and second conducting layers, wherein one or more parts of one of the conducting layers is transparent to optical radiation; an optical radiation source for generating an excitation beam for irradiating the semiconductor layer through the transparent conducting layer parts, the optical radiation being capable of generating free charge carriers through the entire thickness of the semiconductor layer; and one or more beam shaping elements for controlling the excitation beam to create a photo-induced pattern of charge carriers in the semiconductor layer for controlling THz radiation propagating in the PPWG; wherein the optical radiation source and beam shaping means are configured to generate transient photo-induced patterns by providing the excitation beam irradiating the semiconductor layer in a pulsed manner with a maximum pulse length t