Abstract
The hydroxyl-concentration distributions near the binding interface formed by heating contacted flat surfaces of various kinds of silica glasses at 1150°C were measured. The hydroxyl contents near the binding interface formed by the silica glass plates containing 1150 wt. ppm OH decreased, while those of the OH-free silica increased. As for a silica glass with ≈ 200 wt. ppm OH, the change in the hydroxyl content near the binding interface was within the variation of the hydroxyl content, ±≈ 20 wt. ppm.