Dysprosium substituted Ce:YIG thin films with perpendicular magnetic anisotropy for silicon integrated optical isolator applications

Yan Zhang,Juejun Hu,Chuangtang Wang,Qingyang Du,Longjiang Deng,Caroline A Ross,Wei Yan,Lei Bi

doi:10.1063/1.5112827

Abstract

In this report, dysprosium substituted Ce1Y2Fe5O12 (Ce:YIG) thin films (Dy:CeYIG) with perpendicular magnetic anisotropy (PMA) are successfully deposited on silicon and silicon-on-insulator waveguides by pulsed laser deposition. The structural, magnetic, and magneto-optical properties of Dy:CeYIG films are investigated. We find that increasing dysprosium concentration leads to a decreased out-of-plane magnetic saturation field. Dy2Ce1Fe5O12 and Dy2Ce1Al0.4Fe4.6O12 thin films show PMA dominated by magnetoelastic effects due to thermal mismatch strain. These films further exhibit high Faraday rotation and low optical loss. Our work demonstrates that Dy substitution is an effective way to induce PMA in Ce:YIG thin films without compromising their magneto-optical figure of merit, making this material promising for self-biased transverse electric mode optical isolator applications.

Highlights

Integrated optical isolators or circulators are essential components of photonic integrated circuits (PICs) and optical communication systems.1,2 Optical isolators allow one-way transmission of light, protecting sensitive components such as lasers and amplifiers from harmful reflections
The optical isolator structure based on magneto-optical nonreciprocal phase shift (NRPS) effects was demonstrated using epitaxial Ce:YIG films as the guiding layer,4 by bonding epitaxial Ce:YIG films onto semiconductor waveguides5–9 or by monolithically depositing polycrystalline Ce:YIG with YIG seed layers on silicon photonic devices
For transverse electric (TE) isolators based on the asymmetric magneto-optical cladding configuration, it is desirable to develop a magneto-optical material which exhibits perpendicular magnetic anisotropy (PMA) to facilitate operation with a low applied magnetic field or even self-biased operation

Summary

INTRODUCTION

Integrated optical isolators or circulators are essential components of photonic integrated circuits (PICs) and optical communication systems. Optical isolators allow one-way transmission of light, protecting sensitive components such as lasers and amplifiers from harmful reflections. The optical isolator structure based on magneto-optical nonreciprocal phase shift (NRPS) effects was demonstrated using epitaxial Ce:YIG films as the guiding layer, by bonding epitaxial Ce:YIG films onto semiconductor waveguides or by monolithically depositing polycrystalline Ce:YIG with YIG seed layers on silicon photonic devices.. For TE isolators based on the asymmetric magneto-optical cladding configuration, it is desirable to develop a magneto-optical material which exhibits perpendicular magnetic anisotropy (PMA) to facilitate operation with a low applied magnetic field or even self-biased operation. The negative magnetostriction coefficient of DyIG suggests that Dy substitution may compensate or even overcome the positive magnetoelastic response of Ce ions in Ce:YIG films, leading to PMA DyCeYIG thin films with large magneto-optical coefficients essential for TE mode device integration.

EXPERIMENTAL METHODS

FILM STRUCTURE AND MAGNETIC PROPERTIES

MAGNETO-OPTICAL AND OPTICAL PROPERTIES

CONCLUSION