| 摘要 |
PURPOSE:To prevent the loss of the sharpness of the pattern transferred by ultraviolet exposure through a quartz glass of an optical instrument, by using a quartz glass heat-treated at a specific temperature for a specific time. CONSTITUTION:A quartz glass emitting fluorescent light having principal peaks at 283nm, 473nms and 649nm when irradiated with ultraviolet radiation is treated at 300-1,200 deg.C for a proper period to obtain the objective quartz glass useful as a material for optical instrument. At least a part of the fluorescent light having a peak at 283nm is converted to the fluorescent light of 649nm wavelength. The loss of sharpness of the pattern transferred by ultraviolet exposure can be prevented by using the obtained quartz glass as a material for an optical instrument. |
