Resonance enhancement of magnetic Faraday rotation

TL;DR

This paper analyzes how different resonator structures can enhance magnetic Faraday rotation, highlighting that slow wave resonators offer advantages over microcavities, especially in lossy magnetic materials.

Contribution

It provides a comparative analysis demonstrating the fundamental advantage of slow wave resonators over microcavities for enhancing Faraday rotation in lossy magnetic materials.

Findings

Slow wave resonators outperform microcavities in Faraday rotation enhancement.

Enhancement of Faraday rotation often accompanies increased ellipticity and absorption.

Slow wave resonators mitigate the side effects associated with resonant enhancement.

Abstract

Magnetic Faraday rotation is widely used in optics. In natural transparent materials, this effect is very weak. One way to enhance it is to incorporate the magnetic material into a periodic layered structure displaying a high-Q resonance. One problem with such magneto-optical resonators is that a significant enhancement of Faraday rotation is inevitably accompanied by strong ellipticity of the transmitted light. More importantly, along with the Faraday rotation, the resonator also enhances linear birefringence and absorption associated with the magnetic material. The latter side effect can put severe limitations on the device performance. From this perspective, we carry out a comparative analysis of optical microcavity and a slow wave resonator. We show that slow wave resonator has a fundamental advantage when it comes to Faraday rotation enhancement in lossy magnetic materials.