Exploring magneto-optical anisotropy on Tb₃Al₃Ga₂O₁₂ single crystal for visible-infrared Faraday isolators

Tb₃Al₃Ga₂O₁₂ (TAGG) crystal possesses excellent optical and magneto-optical properties and is considered a promising crystal for Faraday isolators. In this work, we report the magneto-optical anisotropy of the TAGG crystal for the first time, which is crucial for the actual processing and usage of the crystal devices. Herein, a high-quality non-cracked TAGG single crystal is grown by the Czochralski method, and it exhibits a high transmittance of more than 80% in the wavelength range of 400–1600 nm. The magneto-optical anisotropy is determined by studying the magneto-optical properties along three different crystal orientations (100), (110), and (111). The results demonstrate that the (111) orientation exhibits superior magneto-optical performance with the largest Verdet constants of 279.4 rad T⁻¹ m⁻¹ at 515 nm, 154.2 rad T⁻¹ m⁻¹ at 650 nm, and 49.5 rad T⁻¹ m⁻¹ at 1064 nm, respectively.