Hydrogen, defects, and compaction of pure and doped vitreous silica

Abstract

Irradiation of vitreous silica results in the formation of optical defects and the compaction of the glass. Irradiation of silica doped with germanium or titanium results in the formation of many more defects, accompanied by compaction. Irradiation of undoped vitreous silica containing large quantities of dissolved molecular hydrogen eliminates the optical defects and reverses the compaction process so that the glass actually expands. Irradiation of hydrogen soaked silica doped with 4% germania results in increased optical absorption, but still leads to expansion of the glass. On the other hand, irradiation of hydrogen soaked silica which contains 3 to 8% titania leads to dramatic increases in optical absorption and to increased compaction of the glass.