Abstract
We report, for the f irst time to our knowledge, generation of a tunable miltiterahertz modulation signal on an optical carrier directly from a single laser source. The modulation frequency, which can be tuned from 0.15 THz to more than 7 THz, is the beat note obtained by varying the spectral separation between the coaxial two-color output of a two-wavelength laser-diode array from 0.32 to 17 nm. The frequency characteristics of the terahertz beat note are determined with a noncollinear intensity autocorrelator. © 1995, Optical Society of America.