Efficient high-power tunable terahertz sources based on intracavity difference frequency generation

We demonstrate tunable (0.8-2.8 THz) narrow-band THz waves using fiber-laser pumped ring cavity, near-degenerate type 0 or type II PPLN OPO's. Over 130 μW (120 μW) of stable CW THz waves were generated at 1.5 (0.8) THz in a periodically-inverted gallium arsenide sample using intracavity difference frequency generation with the type 0 (II) OPOs.