Control of dispersion in photonic crystal waveguides using group symmetry theory

TL;DR

This paper introduces a group theory-based method for dispersion control in photonic crystal waveguides, enabling precise dispersion tailoring through a single geometric parameter, validated experimentally with high accuracy.

Contribution

It presents a novel approach using group symmetry analysis for dispersion engineering, moving beyond trial-and-error design methods.

Findings

Successful dispersion tailoring via mode coupling in photonic crystal waveguides

Ab-initio group theory analysis accurately predicts mode coupling

Experimental results closely match theoretical predictions

Abstract

We demonstrate dispersion tailoring by coupling the even and the odd modes in a line-defect photonic crystal waveguide. Coupling is determined ab-initio using group theory analysis, rather than by trial and error optimisation of the design parameters. A family of dispersion curves is generated by controlling a single geometrical parameter. This concept is demonstrated experimentally on 1.5mm-long waveguides with very good agreement with theory.