Wavelength Conversion by Means of Second-Order Femtosecond Soliton Decay

In this paper, for the first time, we have reported the possibility of designing wavelength converter for second order femtosecond solitons, by studying its decaying behavior after confronting a localized perturbation in dispersion along an optical fiber. In our studies, in addition to the important nonlinearities for femtosecond pulses, such as self steeping and stimulated Ramman scattering, we have investigated the effects of the third and fourth order dispersions. We have realized that inclusion of the fourth order dispersion effect in our calculations makes the soliton decay behavior somewhat symmetric. On the contrary, when β4=0, the soliton decay behave in an asymmetric manner. The nearly symmetric behavior of the emerging pulses from an upward step-like dispersion, made us to change β4 from –0.0002 ps4/km given in references, to –0.001 ps4/km, to achieve a symmetric behavior suitable for wavelength conversion.