Diffraction anomalies in hybrid structures based on chalcogenide-coated opal photonic crystals

TL;DR

This paper investigates diffraction anomalies, specifically Wood anomalies, in hybrid photonic structures with chalcogenide coatings, combining spectroscopic experiments and theoretical analysis to understand their spectral-angular behavior.

Contribution

It provides a combined experimental and phenomenological theoretical study of Wood anomalies in GST225-coated opal photonic structures, highlighting their spectral-angular dependencies.

Findings

Identification of resonance conditions for Wood anomalies

Spectral shifts related to coating thickness

Validation of effective refractive index model

Abstract

The results of spectroscopic studies of the diffraction anomalies (the so-called resonant Wood anomalies) in spatially-periodic hybrid structures based on halcogenide (GST225)-coated opal films of various thickness are presented. A theoretical analysis of spectral-angular dependencies of the Wood anomalies has been made by means of a phenomenological approach using the concept of the effective refractive index of waveguiding surface layer.