Abstract
The optical absorption of point-defect-free glass in the vacuum ultraviolet region is primarily controlled by the concentrations of three- and four-membered ring structures composed of heavily strained Si-O-Si bonds. The main channel of color center formation by excimer laser (7.9 eV) irradiation is not Frenkel-defect generation of oxygen via two-photon absorption processes but a pair generation of and nonbridging oxygen hole centers by the one-photon excitation of these strained bonds with 7.9 eV photons.
- Received 12 March 2001
DOI:https://doi.org/10.1103/PhysRevLett.87.175501
©2001 American Physical Society