Analysis of Perpendicular Crossing Dielectric Waveguides With Various Typical Index Contrasts and Intersection Profiles

We present a rigorous 2D numerical study of the transmission, reflection and crosstalk coefficients of the perpendicular, identical dielectric crossing waveguide with various core-cladding index contrasts for both TE and TM polarizations.Our method is based on a hybrid frequency-domain finite-difference (FD-FD) technique computed with the cross-symmetry model.By varying the intersection profile, such as the circular, filleted, tapered and elliptical shapes, we achieve, even for a large 3.5 to 1.5 index ratio, a low 0.25 dB insertion loss, a nontrivial reduction over the straight direct crossing case.