Broadly tunable phase-stable single-frequency terahertz radiation is generated with an optical heterodyne photomixer. The photomixer is excited by two near-infrared CW diode lasers that are phase locked to the stabilized optical frequency comb of a femtosecond titanium:sapphire laser. The terahertz radiation emitted by the photomixer is downconverted into RF frequencies with a waveguide harmonic mixer and measurement-limited linewidths at the Hertz level are demonstrated.
© 2005 Optical Society of America
Qudsia Quraishi, Martin Griebel, Thomas Kleine-Ostmann, and Rudolf Bratschitsch, "Generation of phase-locked and tunable continuous-wave radiation in the terahertz regime," Opt. Lett. 30, 3231-3233 (2005)