We report experimental data on two types of natural silica, differing in 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 5.12 eV and of the associated emissions at 3.14 eV and 4.28 eV, 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.

CANNAS M, MESSINA F (2004). Bleaching of optical activity induced by UV laser exposure in natural silica. JOURNAL OF NON-CRYSTALLINE SOLIDS, 345-346, 433-437 [10.1016/j.jnoncrysol.2004.08.058].

Bleaching of optical activity induced by UV laser exposure in natural silica

CANNAS, Marco;MESSINA, Fabrizio
2004-01-01

Abstract

We report experimental data on two types of natural silica, differing in 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 5.12 eV and of the associated emissions at 3.14 eV and 4.28 eV, 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.
2004
CANNAS M, MESSINA F (2004). Bleaching of optical activity induced by UV laser exposure in natural silica. JOURNAL OF NON-CRYSTALLINE SOLIDS, 345-346, 433-437 [10.1016/j.jnoncrysol.2004.08.058].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/7152
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