# Quasi-planar optics: computing light propagation and scattering in planar waveguide arrays

## TL;DR

This paper introduces an algorithm for accurately computing light propagation and scattering in coupled planar waveguides, addressing modal cross-talk and out-of-plane scattering in quasi-planar photonics.

## Contribution

It presents a novel numerical algorithm for wave coupling in planar structures and an analytical method to reduce scattering and cross-talk in anisotropic waveguides.

## Key findings

- Algorithm accurately computes wave coupling in various waveguide arrays.
- Analytical methods can significantly reduce scattering and cross-talk.
- Demonstrated effectiveness on plasmonic and volumetric waveguides.

## Abstract

We analyze wave propagation in coupled planar waveguides, pointing specific attention to modal cross-talk and out-of-plane scattering in quasi-planar photonics. An algorithm capable of accurate numerical computation of wave coupling in arrays of planar structures is developed and illustrated on several examples of plasmonic and volumetric waveguides. An analytical approach to reduce or completely eliminate scattering and modal cross-talk in planar waveguides with anisotropic materials is also presented.