EFFECT OF SELF-INDUCED RAMAN-SCATTERING ON SOLITON PROPAGATION-COMPARISON BETWEEN RAMAN RESPONSE FUNCTION-METHOD AND LINEAR-GAIN APPROXIMATION

Pulse delay due to self-induced Raman scattering is calculated for sol iton widths less than 100 fs. Two different methods to modify the nonl inear Schrodinger; equation are directly compared. The calculated dela y time using the Raman response function is smaller than that of linea r-gain approximation, especially for short pulses. The ratio of the re sult of the Raman response function method to that of linear-gain appr oximation is 0.9 for 100-fs pulses and 0.2 for 20-fs pulses.