Generation of 5 pJ THz pulses with 200 kHz repetition rate by femtosecond tilted-pulse-front excitation

Velocity-matched efficient ultrashort THz pulse generation is achieved in a lithium niobate crystal by tilting the intensity front of the Tirsapphire laser excitation pulses. The generated broad-band THz radiation has a divergence smaller than 30 mrad, and a center frequency larger than 2 THz. The energy conversion efficiency is close to 10/sup -5/.