Multipass OPCPA system at 100 kHz pumped by a CPA-free solid-state amplifier

We present a compact few-cycle 100 kHz OPCPA system pumped by a CPA-free picosecond Nd:YVO4 solid-state amplifier with all-optical synchronization to an ultra-broadband Ti:sapphire oscillator. This pump approach shows an exceptional conversion rate into the second harmonic of almost 78%. Efficient parametric amplification was realized by a two stage double-pass scheme with following chirped mirror compressor. The amount of superfluorescence was measured by an optical cross-correlation. Pulses with a duration of 8.7 fs at energies of 18 mu J are demonstrated. Due to the peak power of 1.26 GW, this simple OPCPA approach forms an ideal high repetition rate driving source for high-order harmonic generation. (C) 2016 Optical Society of America