Ultraviolet Absorption Of Hydrogen Related Species In Glassy Silica

Hydrogen is often deliberately added to silica glass in order to improve the ultraviolet (UV) transparency and to minimise defect creation by UV light. It enters into the glass network in the form of silanol (Si-OH) and silicon hydride (Si-H) groups. The vacuum ultraviolet (VUV) range optical absorption of silicon hydride (Si-H) groups in H2 imprefnated silica was investigated and the effect of irradiation by F2 laser on their creation and destruction was studied. The absorption cross section of SiH groups was estimated as less than 3x10-20cm2 at F2 laser photon energy 7.9 eV.