Abstract

Traditionally, pulse shaping of femtosecond pulses is accomplished by first dispersing the pulse using a grating, and modulating the spatially chirped beam at the transform plane of an imaging system. In this paper we introduce regenerative, intra-cavity pulse shaping of chirped pulses. This method has inherent advantages over traditional pulse shaping techniques for producing certain types of pulse shapes, and overcoming limiting processes such as gain narrowing. Using regenerative pulse shaping we demonstrate for the first time 1) amplification beyond the gain narrowing limit, 2) simultaneous amplification of two ~100-fs pulses separated in wavelength by as much as 100 nm, and finally, 3) difference frequency mixing of these two amplified pulses to produce tunable mid-IR (6-12 μm) ultrashort pulses.

© 1996 Optical Society of America