OPTICAL SYNTHETIC QUARTZ GLASS, METHOD FOR HEAT-TREATING THE SAME, AND HEAT-TREATING APPARATUS FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain an optical synthetic quartz glass capable of exhibiting better transmissivity and laser resistance and to provide a method for heat- treating the optical synthetic quartz glass, and a heat-treating apparatus for the same. SOLUTION: This method for heat-treating the optical synthetic quartz glass is characterized in that the periphery of the synthetic quartz glass body which is a material to be treated is covered with an SiO2 powder having >=1×1019 molecules/cm3 dissolved hydrogen molecular concentration on the average and heat-treated in a heating furnace in the method for heat-treating the optical synthetic quartz glass in the heating furnace.