Finite-element modelling of 2/spl times/2 fused-fiber couplers

Here, we investigate the effect of the fused cladding shape in the coupler performance, the fact of the fused cladding being elliptical rather than circular. We accomplish the present investigation by computing the associated supermodes using a scalar finite element formulation in conjunction with the efficient radiation boundary condition, and the adaptive refinement approach above. We consider a symmetric 2x2 fused coupler made of identical fibres with a taper parameter of 0.3.