Patent ID: 6836356
Filing Date: 2004-12-28
Classification: H01S

Abstract:
A phosphate glass composition comprising the following ingredients,a glass network former P2O5 in mole percent P1 from 50 to 75 percent and having a temperature coefficient of refractive index &bgr;1, A glass intermediator XO selected from the oxide group consisting of Al2O3, B2O3, Y2O3, La2O3, and mixtures thereof in mole percent P2 from 5 to 15 percent and having a temperature coefficient of refractive index &bgr;2, A rare earth dopant selected from La2O3, Er2O3, Yb2O3 and mixtures thereof in mole percent P3 from 3 to 10 percent and having a temperature coefficient of refractive index &bgr;3, and A glass modifier MO selected from BaO, BeO, MgO, SrO, CaO, ZnO, PbO and mixtures thereof in mole percent P4 from 20 to 41 percent and having a temperature coefficient of refractive index &bgr;4, Wherein the temperature coefficient of refractive index &bgr; of the phosphate glass composition is give by, Î²=&Sum;i=1N&it;â€ƒ&it;Î²i&it;Pi&Sum;i=1N&it;â€ƒ&it;Pi&it;â€ƒ&it;with&it;â€ƒ&it;&Sum;i=1N&it;â€ƒ&it;Pi=100and &bgr; lies between âˆ’2.0Ã—10âˆ’6 to 2.0Ã—10âˆ’6 Kâˆ’1.