Spectroscopy Laser-based terahertz generation & applications
Superior to alternative methods, optoelectronic techniques propel terahertz applications out of the lab and into the real world. One physical effect involves two laser beams at adjacent frequencies focusing on a semiconductor; another effect involves an ultrafast laser pulse separating charge carriers in a photoconductive switch. In combination with suitably structured antennas, these two effects generate electromagnetic radiation in the difficult-to-access terahertz region. Some of the principles of continuous-wave (CW) and pulsed terahertz sources are described here while exploring emerging applications."