A frequency-agile ring-cavity THz-wave parametric oscillator pumped by a 200-Hz Q-sw Nd:YAG laser

We developed a THz-wave parametric oscillator (TPO) with a ring-cavity configuration pumped by a 200-Hz repetition-rate Q-sw Nd:YAG laser. Three mirrors were used to form the TPO cavity, which contained an MgO:LiNbO/sub 3/ nonlinear optical crystal. THz-wave pulses synchronized with the pump repetition rate were generated, and a tunable range from 1.3 to 2.3 THz was obtained.