Role of boron elements in highly Tb₂O₃ concentrated glasses prepared for Faraday rotation in the visible region

Abstract

A large amount of Tb₂O₃ has successfully been incorporated into a borate glass with a molar composition of 5B₂O₃-3Ga₂O₃-3SiO₂-P₂O₅. Raman scattering analysis revealed the existence of isolated orthoborate (BO₃)^3- groups with increasing rare-earth content. The obtained glass exhibited an excellent Faraday rotation effect in the visible region, which offered the Verdet constant of -146 rad./(Txm) at 632.8 nm at 300 K.