The observation of chirped stimulated Raman scattered light in fibers.

Stimulated Raman scattering in fibers using 36 psec transform limited pulses at 532 nm reveal for the first time that the Raman Strokes pulse in strongly chirped near the point of Raman pulse generation. The significance of this result lies in the fact that the fiber is sufficiently short that the effects of group velocity dispersion, self-phase modulation, and cross- phase modulation are minimal and hence cannot explain the source of the chirp. Direct measurements of the chirp in the regime of normal group velocity dispersion reveal a positively chirped spectrum suggesting the possibility of external grating compression of the Raman pulse.