Terahertz generation by means of optical lasers

Generation of high‐power radiation in terahertz frequency range 0.3 – 10 THz is a fast developing research area attracting considerable interest over the past years due to its important applications in spectroscopy, communication, biomedical imaging and tomography. A brief review of laser‐based generation methods is presented, starting from the schemes of resonance laser excitation of photoconductive materials, organic molecules and ionized gases, and proceeding with more detailed description of non‐resonance schemes of optical rectification and difference frequency generation in materials with high optical nonlinearity. Recent progress achieved in both groups of methods is compared. (© 2008 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)