Generation of narrow-bandwidth tunable picosecond IR pulses by difference frequency mixing of stretched pulses

Summary form only given. It has been demonstrated about two decades ago that sum frequency generation by either randomly or regularly phase modulated conjugated waves leads to the removal of chirp in both space and time domains. Recent demonstration of the same method with the adoption of grating induced pulse stretching has shown that a bandwidth narrowing by factor of 30 with high overall efficiency is feasible. Parametric amplification also has been shown to offer a variety of possibilities to control the pulse chirp. In the paper we investigate one of those that has obvious practical application. We demonstrate chirp canceling in the difference frequency generation accomplished by a parametric amplifier. The technique offers an easy way to produce near transform limited IR pulses in the duration range of 2-20 ps with both wavelength and bandwidth being adjustable.