Title :
Photosensitivity of rare-earth-doped ZBLAN fluoride glasses
Author :
Williams, Glen M. ; Tsai, Tsung-Ein ; Merzbacher, Celia I. ; Friebele, E. Joseph
Author_Institution :
Div. of Opt. Sci., Naval Res. Lab., Washington, DC, USA
fDate :
8/1/1997 12:00:00 AM
Abstract :
We have performed experiments to elucidate the mechanism of photosensitivity in rare-earth-doped fluorozirconate (ZBLAN) glasses. Glasses doped with Ce, Tb, Tm, and Pr were studied. Permanent holographic gratings were written in bulk samples using 248 nm light, with the strongest gratings observed in Ce:ZBLAN. Ultraviolet (UV) induced changes in both absorption and electron spin resonance (ESR) spectra were observed. In the Ce-doped glasses, the grating formation dynamics were recorded as a function of write beam intensity and Ce concentration. The results indicate that the mechanism of photosensitivity involves color center(s) creation through a stepwise two photon excitation of a Ce ion. The color center(s) can be subsequently bleached by a single photon at 248 nm
Keywords :
aluminium compounds; barium compounds; cerium; colour centres; holographic gratings; impurity absorption spectra; optical fibre fabrication; optical fibre testing; optical saturable absorption; paramagnetic resonance; sensitivity; sodium compounds; zirconium compounds; 248 nm; Ce concentration; Ce-doped glasses; Ce:ZBLAN; ESR spectra; UV induced changes; ZBLAN:Ce; ZrF4-BaF2-LaF3-AlF3-NaF:Ce; bleached; electron spin resonance spectra; grating formation dynamics; permanent holographic gratings; photosensitivity; rare-earth-doped ZBLAN fluoride glasses; rare-earth-doped fluorozirconate glasses; stepwise two photon excitation; strongest gratings; write beam intensity; Bragg gratings; Fiber gratings; Fiber lasers; Gas lasers; Glass; Holographic optical components; Holography; Optical fibers; Paramagnetic resonance; Solid lasers;
Journal_Title :
Lightwave Technology, Journal of
