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

Abstract
We report the generation of ultrashort pulses by a barium borate traveling-wave parametric converter pumped b y a 200-fs pulse at 0.6 μm from a dye-laser source. With a pump energy of less than 100 μJ and type II phase matching, we obtained a 0.75-3-μm 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.