Tunable femtosecond pulses close to the transform limit from traveling-wave parametric conversion

We report the generation of ultrashort pulses by a barium borate traveling-wave parametric converter pumped by a 200-fs pulse at 0.6 um from a dye-laser source. With a pump energy of less than 100 uJ and type II phase matching, we obtained a 0.75-3-um tuning range, 15-20% total conversion efficiency, and a pulse duration comparable with that of the pump. In part of the tuning range the time-bandwidth product of the tunable pulses was 0.7, the same value as for the pump