Semiconductor device generates terahert¥radiation

Differencefrequency mixing in GaAs/GaAlAs multiple quantum wells (MQWs) has been used to produce 12 µW at an output wavelength of 118 µm, believed to be the highest output power reported at this farinfrared wavelength. Researchers from Swales & Associates (Beltsville, MD), NASA/Goddard Space Flight Center (Greenbelt, MD), Johns Hopkins University (Baltimore, MD), and the Laboratory for Physical Sciences (College Park, MD) collaborated to make a compact, solidstate semiconductor mixer device for local oscillator sources used in highresolution laser heterodyne spectrometers.

Fiber bundle sensor enables multiple analyses