Energy Redistribution At The Interaction Between Two Femtosecond-solitons In Optical Fibers

Abstract

shift. The latter is equivalent to the noninstantaneous Kerr effect [2,31. It was experimentally measured that the peak gain of the Raman spectrum is at 440 cm'l frequency shift which corresponds to a delay time of 75 fsec in the response function. Flence, any two femtosecond-puls es, separated by a time period smaller than or comparable to 75 fsec, Raman scattering would occur besides the well-known soliton-soliton i nteraction. During the process, the energy in the two pulses is redistributed. The redistribution ends up with the formation o f two new solitons which can be completely separated. The intensities and central wavelengths o f the two new solitons are different from each other and different from those of the initial solitons. In Fig. 1, the numerical results of the interaction between two identical solitons of 40 femtoseconds in width and 1.51 urn in center wavelength are shown. The initial pulse separation is 140 fsec. The dashed and solid curves depict the initial and final solitons, respectively. It has been observed that the energy redistribution in the interaction between t wo femtosecond-soli tons depends on the initial soliton intensity, soliton separation, relative phase, and wavelength difference between the two solitons. In Fig. 2, the results of the collision between two solitons of the same width at 40 fsec but different c entral wavelengths at 1.5 and 1.51 pm, respectively, are shown. Here, the dependence on initial relative phase can be seen. In this paper, the dependences of e nergy redistribution on several initial parameters will be presented. Meanwhile, the mechanism of energy redistribution during the interaction between two femtosecond-soli tons will be discussed.