P. Cheben et Ml. Calvo, A photopolymerizable glass with diffraction efficiency near 100% for holographic storage, APPL PHYS L, 78(11), 2001, pp. 1490-1492
Permanent holographic storage has been demonstrated in a photopolymerizable
organically modified silica glass. The glass was prepared by dispersing a
titanocene photoinitiator and a high refractive index acrylic monomer in a
porous silica matrix. This glass exhibits unprecedented sensitivity and ref
ractive index change upon a moderate exposure to green light and can be fab
ricated in thickness up to several millimeters. A photopolymerizable storag
e medium of such a thickness with good holographic properties is needed for
practical holographic storage devices. Lack of such medium has been consid
ered the main obstacle in development of write-once holographic memories. I
n our glass, we have stored permanent volume holograms of diffraction effic
iency approaching 100% and refractive index modulation up to 4.5 x 10(-3),
making this photopolymerizable material suitable for use in holographic dat
a storage. (C) 2001 American Institute of Physics.