Bleaching of optical activity induced by UV Laser exposure in natural silica
Materials Science
2009-11-10 v1 Disordered Systems and Neural Networks
Abstract
We report experimental data on two types of natural silica, differing for their OH content, irradiated with UV photons (4.66 eV) from a pulsed Nd:YAG laser. Irradiation induces a reduction of the absorption band at 5.12eV and of the associated emissions at 3.14eV and 4.28eV, ascribed to twofold coordinated Ge (=Ge'') centers pre-existing in our samples. The bleaching is mainly due to the post-irradiation conversion of =Ge'' into the paramagnetic H(II) center via trapping of a H atom. Comparison with literature data points out the peculiarities of silica with a low Ge concentration as regards UV induced transformations.
Keywords
Cite
@article{arxiv.cond-mat/0410585,
title = {Bleaching of optical activity induced by UV Laser exposure in natural silica},
author = {M. Cannas and F. Messina},
journal= {arXiv preprint arXiv:cond-mat/0410585},
year = {2009}
}
Comments
Accepted for publication on Journal of Non crystalline solids