Giant quadratic magneto-optical response of thin YIG films for sensitive magnetometric experiments

TL;DR

This paper demonstrates a significant quadratic magneto-optical effect in thin YIG films, which can surpass linear effects and is optimized through experimental conditions, enhancing sensitive magnetometric applications.

Contribution

The study provides the first quantification of quadratic magneto-optical effects in thin YIG films and shows how to optimize these effects for magnetometry.

Findings

Quadratic magneto-optical response exceeds linear response in 50 nm YIG films.

The quadratic effect reaches 450 urad, comparable to other magnetic materials.

Wavelength tuning is crucial for maximizing the quadratic magneto-optical effect.

Abstract

We report on observation of a magneto-optical effect quadratic in magnetization (Cotton-Mouton effect) in 50 nm thick layer of Yttrium-Iron Garnet (YIG). By a combined theoretical and experimental approach, we managed to quantify both linear and quadratic magneto-optical effects. We show that the quadratic magneto-optical signal in the thin YIG film can exceed the linear magneto-optical response, reaching values of 450 urad that are comparable with Heusler alloys or ferromagnetic semiconductors. Furthermore, we demonstrate that a proper choice of experimental conditions, particularly with respect to the wavelength, is crucial for optimization of the quadratic magneto-optical effect for magnetometry measurement.