Synthetic silica glass optical material having high resistance to optically induced index change

摘要

Disclosed is a synthetic silica glass optical material having high resistance to optical damage by ultraviolet radiation in the ultraviolet wavelength range, particularly in the wavelength region of less than about 250 nm and particularly, exhibiting a low laser induced density change. The synthetic silica glass optical material of the present invention contains at least about 0.1 ppm of aluminum and H₂ concentration levels greater than about 0.5x10¹⁷ molecules/cm². Additionally, the synthetic silica optical material of the present invention exhibits an H₂ to Al ratio of greater than about 1.2, as measured in x10¹⁷/cm³ molecules H₂ per ppm Al.