Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

Provided is a glass material having a high light transmittance in a short wavelength range and easily producible. A glass material contains, in terms of % by mole, 5 to less than 30% Pr.sub.2O.sub.3 and 0.1 to 95% B.sub.2O.sub.3.

Provided is a glass material having a high light transmittance in a short wavelength range and easily producible. A glass material contains, in terms of % by mole, 5 to less than 30% Pr.sub.2O.sub.3 and 0.1 to 95% B.sub.2O.sub.3.

Optically transparent glass ceramic materials comprising a glass phase containing and a crystalline tungsten bronze phase comprising nanoparticles and having the formula M.sub.xWO.sub.3, where M includes at least one H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Cu, Ag, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, and U, and where 0<x<1. Aluminosilicate and zinc-bismuth-borate glasses comprising at least one of Sm.sub.2O.sub.3, Pr.sub.2O.sub.3, and Er.sub.2O.sub.3 are also provided.

Optically transparent glass ceramic materials comprising a glass phase containing and a crystalline tungsten bronze phase comprising nanoparticles and having the formula M.sub.xWO.sub.3, where M includes at least one H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Cu, Ag, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, and U, and where 0<x<1. Aluminosilicate and zinc-bismuth-borate glasses comprising at least one of Sm.sub.2O.sub.3, Pr.sub.2O.sub.3, and Er.sub.2O.sub.3 are also provided.

Provided is a magneto-optic element that enables easy size reduction of an optical isolator. A magneto-optic element is formed of two or more magnetic members joined together.

Provided is a magneto-optic element that enables easy size reduction of an optical isolator. A magneto-optic element is formed of two or more magnetic members joined together.

Optically transparent glass ceramic materials comprising a glass phase containing and a crystalline tungsten bronze phase comprising nanoparticles and having the formula M.sub.xWO.sub.3, where M includes at least one H, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Zn, Cu, Ag, Sn, Cd, In, Tl, Pb, Bi, Th, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu, and U, and where 0<x<1. Aluminosilicate and zinc-bismuth-borate glasses comprising at least one of Sm.sub.2O.sub.3, Pr.sub.2O.sub.3, and Er.sub.2O.sub.3 are also provided.

A solid state method of producing inorganic nanoparticles using glass is disclosed. The nanoparticles may not be formed until the glass is reacted with or degraded by contact with a fluid in vivo or in vitro.