Efficient tuneable bandwidth frequency mixing using chirped pulses

Bandwidth and efficiency have been measured in a series of experiments of t ype II mixing of previously chirped 50 fs pulses. It has been found that if the input pulses have chirps of opposite sign, the bandwidth of the genera ted pulse can be broader than that with transform limited input pulses unde r some conditions and significantly narrower under others. The bandwidth an d the spectral position of the output pulse can be adjusted independently b e adjusted independently by varying the chirp ratio and the relative timing of the input pulses, respectively. In addition to obtaining the highest ac hievable bandwidth and a 6 x higher efficiency, the spectral shape of the g enerated pulse is smoother and more symmetrical than that using transform l imited pulses. (C) 1999 Elsevier Science B.V. All rights reserved.