High-energy, high-contrast, multiterawatt laser pulses by optical parametric chirped-pulse amplification

We describe a compact, reliable, high-power, and high-contrast noncollinear optical parametric chirpedpulse amplifier system. With a broadband Ti:sapphire oscillator and grating-based stretching and compression, the chirped pulses are amplified from 0.1 nJ to 122 mJ in type I beta-barium berate optical parametric chirped-pulse amplifiers with a total gain of over 109 at 10 Hz repetition rate. Pulse compression down to 19-fs duration achieved after amplification indicates a peak power of 3.2 TW at an average power of 0.62 W. The prepulse contrast is measured to be less than 10-8 on picosecond time scales. (C) 2007 Optical Society of America.