Optilab’s Terahertz Source is a set of fully integrated optical heterodyne signal sources packaged in a 1u rack mount configuration. Based on Tunable Wavelength Laser (TWL) systems, the Optical Heterodyne Source series produce optical heterodyne signals up to 10 Terahertz. An optical heterodyne is a signal produced by the frequency beat of two optical sources. The beating makes the optical signals detectable by GHz and slower, square-law detectors such as PDs and finds varied uses in LIDAR, spectroscopy and other high phase-sensitivity applications. The Optical Heterodyne Source series provides high accuracy and high stability optical heterodyne signals over large signal range. The integrated GUI software gives the user full control of the optical heterodyne signal.