A fast frequency-tunable ring-cavity THz-wave parametric oscillator

We report on a rapid frequency-tunable THz-wave parametric oscillator (TPO) with a ring-cavity configuration. A three-mirrored cavity was used as the TPO cavity, which contained a MgO:LiNbO/sub 3/ nonlinear optical crystal. Fast frequency tuning was obtained by rotating a single mirror mounted on a Galvano-optical beam scanner. Consequently, continuous tunability was successfully obtained in the range from 0.7 to 2.6 THz. The THz-wave output exceeded 100pJ/pulse in a broad range from 1.0 to 1.5 THz.