Ultralarge magneto-optic rotations and rotary dispersion in terbium gallium garnet single crystal.

Abstract

We report systematically acquired data on the Verdet constant of terbium gallium garnet for wavelengths ranging from visible to near-infrared (405-830 nm) regime. Our experimental method of Stokes polarimetry is based on the Fourier decomposition of the received light intensity and allows unambiguous determination of both the Faraday rotation and the ellipticity of the emergent light. Temperature-dependent investigations in the range of 8-300 K extend earlier reports and verify the Verdet's constant direct dependence on the magnetization, whose first-order approximation is simply a manifestation of the Curie's law. Further, a least-squares fitting of the experimental data correlates well with theoretical predictions. At a wavelength of 405 nm and temperature of 8 K, the rotation is approximately 500°.