摘要 |
<p>According to one aspect of the present invention an optically active glass contains Sb2O3, up to about 4 mole % of an oxide of a rare earth element, and 0-20 mole % of a metal halide selected from the group consisting of a metal fluoride, a metal bromide, a metal chloride, and mixtures thereof, wherein this metal is a trivalent metal, a divalent metal, a monovalent metal, and mixtures thereof. In addition, any of the glass compositions described herein may contain up to 15 mole % B2O3 substituted for an equivalent amount of Sb2O3.</p> |