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1770640 
Journal Article 
Fluorinated silicate glass for conventional and holographic optical elements - art. no. 654507 
Glebov, L 
2007 
Unk 
Proceedings of SPIE
ISSN: 0277-786X
EISSN: 1996-756X 
PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) 
6545 
54507-54507 
WOS:000248191900005 
This presentation is a survey of results of a long-term
research at the laboratory of photoinduced processes at CREOL/UCF. A highly homogeneous and
transparent sodium-zinc-aluminum-silicate glass doped with fluorine and bromine was developed.
Glass is transparent from 220 to 2700 nm. It is a crown-type optical glass having refractive
index at 587.5 rim n(d)=1.4959 and Abbe number v(d)=59.2. This glass shows low dependence of
refractive index on temperature dn/dt < 10(-7) 1 /deg. Absorption coefficient in the near IR
region is about 10(-4) cm(-1). Glass can withstand multi-kilowatt laser beams. Nonlinear
refractive index is the same as for fused silica. Laser damage threshold for 8 ns is about 40/cm
(2). This glass becomes a photosensitive one by doping with silver and cerium. It demonstrates
refractive index decrement after exposure to UV radiation followed by thermal development and
therefore is used for phase volume hologram recording. Spatial modulation of refractive index
resulted from precipitation of nano-crystalline phase of sodium fluoride. The main mechanism of
refractive index decrement is a photoelastic effect resulted from strong tensions generated in
both crystalline and vitreous phases because of difference in their coefficients of thermal
expansion. Volume Bragg gratings recorded in this glass, show extremely narrow spectral and
angular selectivity and have low losses combined with high tolerance to laser radiation. These
gratings possess a unique ability to produce laser beam transformations directly in angular
space. This feature paves a way to creation of high power lasers with. stable narrow emission
spectra and diffraction limited divergence. 
photosensitive; athermal optical glass; holographic optical elements