Reducing Radiative Loss in Intersecting Waveguides by Fractionally Doping the Intersection Region

A multiple scattering analysis of single mode intersecting optical waveguides predicts that coupling from guided to radiation fields (i.e., an insertion loss) can be reduced by modifying the refractive index in the volume common to both guides. We observe a significant reduction in radiative loss for both polarizations with this modification. © 1990 IEEE