Effect of hole-shape irregularities on photonic crystal waveguides

TL;DR

This paper investigates how irregularities in hole shapes within photonic crystal waveguides affect their spectral properties and radiation losses, highlighting the importance of hole area variability and shape correlation.

Contribution

It introduces a quantitative analysis of hole-shape irregularities' impact on photonic crystal waveguides using Bloch-mode expansion, emphasizing the role of hole area standard deviation.

Findings

Hole area variability significantly influences spectral and loss characteristics.

Correlation angle of irregular shapes affects disorder impact.

Potential pathways for improving photonic crystal quality are identified.

Abstract

The effect of irregular hole shape on the spectrum and radiation losses of a photonic crystal waveguide is studied using Bloch-mode expansion. Deviations from a perfectly circular hole are characterized by a radius fluctuation amplitude and correlation angle. It is found that the parameter which determines the magnitude of the effect of disorder is the standard deviation of the hole areas. Hence, for a fixed amplitude of the radius fluctuation around the hole, those effects are strongly dependent on the correlation angle of the irregular shape. This result suggests routes to potentially improve the quality of photonic crystal structures.