Raman Scattering for Spatiotemporal Soliton in a Cylindrical Optical Fiber

A new approach has been developed for the study of Raman scattering of a spatiotemporal optical pulse in a fiber having cylindrical geometry with simultaneous presence of diffraction and dispersion. While the spatiotemporal soliton is described by the modified NLS equation in three dimension, the corresponding Raman vibration is modelled by a damped harmonic oscillator forced by the intensity of the pulse. It is observed that both temporal and spatial features of the pulse get affected by the Raman vibration at different order. Finally it is demonstrated that the decay of the pulse is counteracted by an experimental pumping at a fixed interval along the line of propagation. Our analysis helps to unfold the effect of Raman like perturbation on both the spatial and temporal characteristics of the soliton in cylindrical geometry.