Controlling the optical properties of intersecting waveguides: fractionally doping the intersection region

This is the authors' abstract. We don't add key points for this paper.

Modification of the refractive index of the region common to intersecting waveguides (fractional doping) provides a mechanism independent of intersection angle, for controlling the optical coupling characteristics of this geometry. The authors derive a pair of expressions based on a multiple scattering analysis of intersecting waveguides which predict the coupling behavior as a function of intersection angle and fractional doping for both polarizations. The expressions are in good agreement with experimental data from several different laboratories. The conditions for polarization-independent coupling and polarization splitting are demonstrated.>