Controllable Nonautonomous Waves in Tapered Graded-Index Waveguides

Nonautonomous wave propagation in graded-index (GRIN) waveguide for different tapering profiles is studied. A similarity transformation is used to carry out the analysis, which maps the inhomogeneous generalized nonlinear Schrödinger equation to the standard nonlinear Schrödinger equation. It is found that these different tapering profiles can support both bright and dark similaritons with significantly high intensity. In particular, we study the dynamical behavior of bright and dark similaritons for three different sets of tapering profiles and widths. Interestingly, in the case of periodic width and tapering profile, we observe that the similariton gets annihilated and regenerated after some time during its evolution, along the length of the waveguide.