Theory of Photo Induced Second Harmonic Generation Caused by Phase Transition in Defects System in Silica Glass,
Abstract
To describe inducing of non-zero macroscopic second-order susceptibility in a centro-symmetric media such as the glass we suppose that a pump wave excites electrons from certain donor states in the middle of the v-SiO2 forbidden gap to defect states near the conduction band edge and the conformation of each defect changes significantly owing to pseudo-Jahn-Teller effect with a certain number of electrons placed in the proper state of the defect. Our cluster calculation performed by MNDO method proves the pseudo-effect to occur in Ge and Al atom substituted for the Si one and in =Ge-O-Ge= diatomio center with a certain defect state occupied by two electrons or by one electron, respectively. The relaxed conformation of the defects is stable since their spontaneous decay is forbidden.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1992
- Accession Number
- ADP007605
Entities
People
- E. M. Dianov
- V. B. Sulimov
- V. O. Sokolov