Model for reflection and transmission matrices of nanowire end facets

TL;DR

This paper introduces a direct computational method for determining the reflection and transmission matrices at nanowire end facets, generalizing Fresnel equations for arbitrary cross sections, with efficient FFT-based calculations.

Contribution

It develops a novel, generalized approach to calculate modal reflection and transmission matrices at nanowire end facets, applicable to arbitrary cross sections.

Findings

Reflection is mainly influenced by modal field confinement.

Average Fresnel reflection of constituent plane waves affects overall reflection.

FFT-based method enables efficient computation of reflection matrices.

Abstract

Nanowires show a large potential for various electrooptical devices, such as light emitting diodes, solar cells and nanowire lasers. We present a direct method developed to calculate the modal reflection and transmission matrix at the end facets of a waveguide of arbitrary cross section, resulting in a generalized version of the Fresnel equations. The reflection can be conveniently computed using Fast Fourier Transforms. We demonstrate that the reflection is qualitatively described by two main parameters, the modal field confinement and the average Fresnel reflection of the plane waves constituting the waveguide mode.