| 摘要 |
A crystallized glass for an optical filter substrate, which has an average linear expansion coefficient alpha<SUB>L </SUB>of from 95x10<SUP>-7</SUP>/° C. to 130x10<SUP>-7</SUP>/° C. at from -30° C. to 70° C. and which has a crystal or the like of Na<SUB>4-x</SUB>K<SUB>x</SUB>Al<SUB>4</SUB>Si<SUB>4</SUB>O<SUB>16 </SUB>(1<x<=4) precipitated therein. Further, a crystallized glass for an optical filter substrate, which comprises from 35 to 60% of SiO<SUB>2</SUB>, from 10 to 30% of Al<SUB>2</SUB>O<SUB>3</SUB>, from 1 to 15% of TiO<SUB>2</SUB>+ZrO<SUB>2</SUB>, from 4 to 20% of Na<SUB>2</SUB>O, from 4 to 20% of K<SUB>2</SUB>O, from 0.1 to 10% of CaO+SrO+Bao, from 0 to 10% of MgO, etc., and which has alpha<SUB>L </SUB>of from 95x10<SUP>-7</SUP>/° C. to 130x10<SUP>-7</SUP>/° C. and which has a crystal or solid solution precipitated therein.
|
