Imaging of Iso-frequency Contours via Resonance-Enhanced Scattering in Near-Pristine Photonic Crystals

TL;DR

This paper introduces a novel method to directly visualize iso-frequency contours in photonic crystals using resonance-enhanced scattering, aligning well with numerical models and aiding in fabrication quality control.

Contribution

The study presents a new visualization technique for iso-frequency contours in photonic crystals based on resonance-enhanced scattering from fabrication imperfections.

Findings

Quantitative agreement with numerical results across the visible spectrum

Applicable to various photonic and plasmonic structures, including quasi-crystals

Provides insights into disorder characteristics for fabrication improvement

Abstract

The iso-frequency contours of a photonic crystal are important for predicting and understanding exotic optical phenomena that are not apparent from high-symmetry band structure visualizations. Here, we demonstrate a method to directly visualize the iso-frequency contours of high-quality photonic crystal slabs that shows quantitatively good agreement with numerical results throughout the visible spectrum. Our technique relies on resonance-enhanced photon scattering from generic fabrication disorder and surface roughness, so it can be applied to general photonic and plasmonic crystals, or even quasi-crystals. We also present an analytical model of the scattering process, which explains the observation of iso-frequency contours in our technique. Furthermore, the iso-frequency contours provide information about the characteristics of the disorder and therefore serve as a feedback tool to improve fabrication processes.