"TERAHERTZ: microwaves meet infrared at the final frontier"
With all the advances in solid-state communications � from long-wavelength, very low-frequency radio waves that talk to submerged submarines, to short-wavelength, very high-frequency light waves that communicate with lasers � you would think the whole electromagnetic spectrum was covered. You'd be wrong. There exists a gap, centered at 1 trillion cycles per second, that the solid-state era has only begun to bridge. The terahertz gap is the last frontier in the EM spectrum. Terahertz frequencies are where microwaves meet infrared light waves. Microwaves are "millimeter wavelengths" whereas infrared is "nanometer wavelength," leaving the terahertz gap nestled in between at "micron wavelengths."
Audio Interviews / Text: http://eetimes.com/article/showArticle.jhtml?articleId=18402806