Shrinkage control in a photopolymerizable hybrid solgel material for holographic recording.
We report the correction of the shrinkage observed during UV postrecording curing in a holographic solgel material that was recently achieved by the use of various chemical formulations for the composition of the hybrid supporting matrix. We found that a chemical modification of the matrix noticeably attenuates the shrinkage (from 1.3% to 0.4% of the material's initial thickness with the inclusion of just 20% tetramethylorthosilicate), providing a material with improved stability for permanent data storage applications. The holographic properties of samples with different binders are also reported. In addition, a theoretical study has revealed the way by which to compensate for angular deviation in the Bragg condition during UV postrecording by tailoring the binder shrinkage (s), the maximum refractive-index modulation capability of the photosensitive mixture (deltan), or both.
Instituto Nacional de Técnica Aeroespacial, Laboratorio de Instrumentación Espacial, Torrejón de Ardoz, 28850 Madrid, Spain.
Gonzalo
G
Ramos
Alberto
A
Alvarez-Herrero
Tomas
T
Belenguer
Francisco
F
del Monte
David
D
Levy