Light guiding in a slot waveguide that includes an additional confining core region

Abstract

We present a design of a slot waveguide in which the core layer is orthogonally slotted to form a rectangular sub-core. While the overall guiding and coupling efficiency remains the same as a conventional slot waveguide, the field confinement is enhanced and appears two-dimensional. The waveguiding is controllable by selecting the intermediate index as well as various geometrical parameters. In addition, by changing different variables, the linear/nonlinear dispersion and birefringence can be tailored with extended ranges. Constant-dispersion points, where the dispersion is insensitive to size changes, are also demonstrated.