Thermal stability of the 248-nm-induced presensitization process in standard H2-loaded germanosilicate fibers.
Grating growths through exposure of presensitized standard fibers to KrF light were recorded in various experimental condition. It is shown that there exists an optimum sensitization fluence at which the efficiency of the sensitization process is higher. Isochronal thermal annealing of pre-exposed fibers led to a decrease in the sensitization-induced enhancement of photosensitivity. IR-absorption spectroscopy was carried out in fibers or preform plates to monitor the attenuation ascribed to H-bearing species in the same samples. The annealing-induced decay in photosensitivity cannot be correlated with those of the H-bearing species in the whole temperature range (110 degrees C-800 degrees C). This indicates that the enhancement of photosensitivity comes from the transformation of more than one species.
Lancry
Matthieu
M
Unité Mixte de Recherche, Centre National de la Recherche Scientifique 8523, Centre d'Etudes et de Recherches Lasers et Applications, Université des Sciences et Technologies de Lille, Bâtiment P5, 59655 Villeneuve d'Ascq, France.
Niay
Pierre
P
Bailleux
Stéphane
S
Douay
Marc
M
Depecker
Cristophe
C
Cordier
Patrik
P
Riant
Isabelle
I