Birefringence-mediated enhancement of the magneto-optical activity in anisotropic magnetic crystals

TL;DR

This paper demonstrates that birefringence in anisotropic magnetic crystals can significantly enhance magneto-optical activity, enabling nearly 100% light modulation, with potential applications in microscopy and pump-probe techniques.

Contribution

It reveals that optical birefringence can be harnessed to boost magneto-optical effects, contrary to traditional views, through experimental, analytical, and numerical analysis of FeBO3 crystals.

Findings

Significant increase in magneto-optical activity observed.

Nearly 100% magneto-optical light modulation achieved.

Applicable to other birefringent magneto-optical crystals.

Abstract

Optical anisotropy is usually treated as an unfavorable condition for the magneto-optical measurements since it is known to diminish the Faraday rotation concerning the case of the isotropic medium. Here we show that the situation could be quite opposite: a phenomenon of birefringence mediated enhancement of the magneto-optical activity appears if the incident light polarization and angle of incidence are set properly. The present study relies on the experimental, analytical, and numerical studies of iron borate $\mathrm{FeBO_3}$ crystals. We demonstrate a significant increase of the magneto-optical activity resulting in nearly $100\%$ magneto-optical light modulation magnitude. The approach applies to other types of birefringent crystals with the magneto-optical response that makes it crucial for various practical applications, including magneto-optical microscopy, pump-probe studies, and others.