Patent ID: 7265070
Filing Date: 2007-09-04
Classification: C03C

Abstract:
1. A synthetic silica glass optical material for use, and resistant to optical damage, in the wavelength region of less than 250 nm, the synthetic silica glass optical material containing aluminum concentration in an amount greater than 0.1 ppm, containing H 2 concentration levels greater than about 0.5×10 7 molecules/cm 3 , exhibiting an H 2 to Al ratio that ranges between about 1.2 to 3.5, as measured in 10 17 /cm 3 H 2 per ppm Al, and exhibiting a low induced density change, as evidenced by a wave front distortion greater than zero, wherein a variation in wavefront distortion is less than about 0.5 nm/cm when exposed to at least 4 billion pulses of incident 633 nm light having a pulse energy in a range from about 40 μJ/cm 2 to about 200 μJ/cm 2 .