Analysis of spatiotemporal instability in the presence of simulated Raman Scattering

Spatiotemporal instability in the planar nonlinear dielectric waveguide is analyzed by nonlinear equation, and the expression of Modulation instability (MI) gain in Raman Scattering is obtained. The analysis show that Simulated Raman Scattering will induce the appearance of the new instability region, and make the original every gain raised to increase the frequency range over which the gain occurs in normal and abnormal group velocity dispersion conditions. The peak and region of modulation instability gain will alter and have a similar effect to an amplification or loss with the change of the nonlinear coefficient.