One-dimensional magnetophotonic crystals

TLDR

Artificial control of light localization in one‑dimensional magnetophotonic crystals enables diverse magneto‑optical applications. The authors fabricated two types of one‑dimensional magnetophotonic crystals: Kerr‑mode structures of (SiO₂/SiN)ₖ/Co/(SiN/SiO₂)ₖ and Faraday‑mode structures of (SiO₂/Ta₂O₅)ₖ/Bi:DyIG/(Ta₂O₅/SiO₂)ₖ. Experimental measurements of Kerr and Faraday rotations in the fabricated crystals agree with theory and reveal large enhancements caused by light localization near the magnetic layers.

Abstract

Two types of one-dimensional photonic crystals composed of magnetic and dielectric materials (magnetophotonic crystals) driven, respectively, by Kerr (reflection) and Faraday (transmission) modes were constructed. Their optical and magneto-optical (MO) properties were studied in detail to confirm our theoretical results showing the large Kerr and Faraday effects of the media originating in the localization of light. For the Kerr-mode operation, films with (SiO2/SiN)×k/Co/(SiN/SiO2)×k (k: number of layers) structures were fabricated, while for the Faraday-mode operation, films with (SiO2/Ta2O5)×k/Bi:DyIG/(Ta2O5/SiO2)×k structures were formed. Excellent agreement between the theoretical and experimental results was obtained, where large enhancement in both Kerr and Faraday rotations appeared originating in the localization of light in the vicinity of the magnetic layers. Since the localized state of light can be controlled artificially, the one-dimensional magnetophotonic crystals will impact for various MO applications.