By adding a small amount of absorption to many liquids, it is shown that the stimulated Raman emission and self-phase modulated emission pulse trains are radically shortened from that of a long pulse train of a mode-locked picosecond laser. The first pulses in a picosecond pulse train are more efficient in producing self-focusing because of self-absorption.

• Received 13 July 1970

DOI:https://doi.org/10.1103/PhysRevA.2.2376