Local Normal Mode Coupling and Energy Band Splitting in Elliptically Birefringent 1D Magnetophotonic Crystals

TL;DR

This paper analyzes wave-vector dispersion in elliptically birefringent 1D magnetophotonic crystals, revealing how local mode coupling affects band structure and induces magnetization-dependent band gaps.

Contribution

It introduces a new understanding of mode coupling effects on dispersion and band gap formation in elliptically birefringent magnetophotonic crystals.

Findings

Mode coupling affects wave-vector dispersion.

Normal mode coupling induces magnetization-dependent band gaps.

Conditions for maximizing band splitting are identified.

Abstract

An analysis is presented of wave-vector dispersion in elliptically birefringent stratified magneto-optic media having one-dimensional periodicity. It is found that local normal-mode polarization-state differences between adjacent layers lead to mode coupling and impact the wave-vector dispersion and the character of the Bloch states of the system. This coupling produces extra terms in the dispersion relation not present in uniform circularly birefringent magneto-optic stratified media. Normal mode coupling lifts the degeneracy at frequency band cross-over points under certain conditions and induces a magnetization-dependent optical band gap. This study examines the conditions for band gap formation in the system. It shows that such a frequency-split can be characterized by a simple coupling parameter that depends on the relation between polarization states of local normal modes in adjacent layers. The character of the Bloch states and conditions for maximizing the strength of the band splitting in these systems are analyzed.