Title: Multipass non-collinear optical parametric amplifier for femtosecond pulses
Abstract: We demonstrate a successful recompression of 4.5 mJ, 30 fs femtosecond pulses from a Ti:Sapphire oscillator amplified in a ring multi-pass optical parametric chirped pulse amplifier using beta-barium borate crystal pumped by a commercial frequency doubled Nd:YAG laser. Pulses with duration close to the Fourier transform limit were obtained.