Reporting a novel visible near-infrared {Tb3}[Ga0.1Sc1.9](Al3)O12 single crystal for Faraday isolators

Abstract

The Tb₃Sc₂Al₃O₁₂ single crystal is a well-known magneto-optical material for visible near-infrared Faraday isolators. Unfortunately, its application is severely restricted owing to its drawbacks in bulk crystal growth. The traditional Tb₃Ga₅O₁₂ crystal shows excellent bulk growth attributes. A small substitution of Sc by Ga could potentially improve the Tb₃Sc₂Al₃O₁₂ growth characteristics, while preserving its superior magneto-optical properties. Therefore, in this work, a novel {Tb₃}[Ga_0.1Sc_1.9](Al₃)O₁₂ crystal has been designed by integrating the advantages of Tb₃Sc₂Al₃O₁₂ and Tb₃Ga₅O₁₂ crystals. A high-quality crack-free {Tb₃}[Ga_0.1Sc_1.9](Al₃)O₁₂ single crystal is successfully grown by the Czochralski method for the first time. The full width at half maximum of the rocking curve is as small as 27.18′′, indicating high crystallinity of the as-grown crystal. In comparison with the Tb₃Ga₅O₁₂ crystal, the {Tb₃}[Ga_0.1Sc_1.9](Al₃)O₁₂ crystal possesses a better optical transmittance, a lower weak absorption coefficient, and a larger Verdet constant. Therefore, the novel {Tb₃}[Ga_0.1Sc_1.9](Al₃)O₁₂ single crystal is very promising for visible near-infrared Faraday applications.