SYNTHETIC QUARTZ GLASS FOR LIGHT TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a synthetic quartz glass for light transmission which has low decreasing rate of transmissiveness by laser radiation having high energy density. SOLUTION: The synthetic quartz glass for light transmission has unpaired electron concentration of <=1×1014 pieces/cm3 by measurement of ESR spectrum corresponding to g=2.001±0.002 at room temperature and g=2.001±0.002 and g=2.008±0.002 at a low temperature of <100 K, respectively. In this case, an absolute value of difference in temperature between a surface imaginary temperature and a bulk imaginary temperature is <=50 deg.C.