Picosecond stimulated Raman generation, pump pulse fragmentation, and fragment compression in single-mode optical fibers

Pump pulse depletion has been examined for high peak power (∼ 100 kW) 90 ps pulses from a
Q
-switched and mode-locked Nd:YAG laser in 4 m of single-mode optical fiber. Fragmentation of the fundamental and low Stokes Raman orders has been observed for this cascading process. Pulse compression using an interferometric technique has been carried out, obtaining compression ratios of up to times five, on these fragments which exhibited a negative frequency chirp.