Nondegenerate optical parametric chirped pulse amplification

Summary form only given. While the ultrashort amplification capabilities of optical parametric amplifiers (OPAs) have been demonstrated down to 5 fs, the compression of ultrashort (<100 fs) pulses in thick OPCPA crystals remains largely unexplored. Here, we present the first pulse compression in a highly nondegenerate OPCPA and obtain the shortest pulses produced in OPCPA to date. The design of our OPCPA system is presented. A mode-locked oscillator, which produces 20 fs pulses centered at 820 nm, is used as a seed source. An all-reflective stretcher is used to stretch the seed pulses to 600 ps, with a spectral cut-off width in excess of 100 nm. The OPA consists of two antireflection-coated betabarium borate (BBO) crystals. The reported 60 fs pulses are the shortest pulses reported to date produced in an OPCPA system. A careful compensation of spectral phase in our system should enable 30 fs transform-limited pulses.