He Hernandez-Figueroa

Vectorial finite element modelling of 2D leaky waveguides

An accurate finite element method is described for the analysis of leaky optical waveguides with arbitrary cross-section and inhomogeneous anisotropic dielectrics including loss or gain. The method leads to the iterative solution of a nonlinear matrix eigenvalue problem without compromising the sparsity of the resultant matrices which depend only on the mesh topology. >

Improved all-optical switching in a three-slab nonlinear directional coupler with gain

We propose and study numerically with a split-step finite-element method, an all-optical switching device made of three nonlinear active optical planar waveguides. Solving directly the nonlinear partial differential equations for the transverse electric polarised fields, the method can analyze real slab structures, where the gain is introduced by doping the guiding region with high erbium concentration. The effect of different amount of gain and loss on the switching performance is investigated. The introduction of suitable gain overcomes the problem of performance degradation due to losses, decreases the switching power and allows the input power to be successfully switched, by a simple power control, among all the three output ports. >

CONTROLLED SPATIAL BRIGHT SOLITON EMISSION FROM A NONLINEAR WAVEGUIDE

An efficient technique for controlling the spatial bright soliton emission from a nonlinear waveguide is demonstrated numerically for what is to our knowledge the first time. The principle of this technique is based on the addition of a weak antisymmetric signal as a probe, the control parameters being the amplitude and the phase of the probe. A novel nonlinear device, the three-waveguide soliton coupler, is introduced and discussed as an application.

Marching methods for the solution of the generalized nonlinear Schrodinger equation

Two forms of implementing the Crank-Nicolson method for the case of nonlinear optical propagation are compared with the faster split operator method. Stability and convergence of the methods are also analyzed. It is shown that in general the split operator method does not conserve power to the same degree as the Crank-Nicolson method does and it fails to converge in the case of strong nonlinearity. >