EXPERIMENTAL INVESTIGATION OF THE RAMAN INDUCED SELF-FREQUENCY SHIFT OF ULTRASHORT STOKES PULSES IN OPTICAL FIBERS

The properties of Raman generated Stokes bands after propagation throu gh approximately 1 km of standard communication fibre have been invest igated experimentally in terms of the input pulse parameters for pico- and subpico-second pulses near 1300 nm wavelength. It has been found that the frequency shift of these Stokes bands is primarily determined by the average input power and shows only a weak dependence on the te mporal width (on a picosecond time scale) and on the centre wavelength of the input pulses. On the other hand, the power transferred to the Stokes band depends on both, the average power and the duration of the input pulses.