<title>Digital holographic data storage in photopolymer systems</title>

Abstract

ABSTRACT We report on the holographic storage and recovery of multiple high capacity (800 x 600, 480 kbit) data pages in 250 m and 500 tm thick photopolymer media. The data pages were recovered with raw bit error rates < 5x103, the levelcorrectable by current error correction strategies. Our results demonstrate that photopolymer systems can be fabricated withthe optical quality and low level of scatter required for digital data storage.Keywords: photopolymer, digital holographic data storage 1. INTRODUCTION The lack of appropriate recording materials has been one of the primary obstacles in the technical development ofholographic data storage. Recent advances in photopolymer systems have focused attention on the viability of these materialsfor write-once-read-many-times holographic data Photopolymer materials26 are attractive candidates for write-once-read-many-times applications because they can be designed to have large refractive index contrast and high photosensitivity,record permanent holograms, may be easily processed, and are inexpensive. Holographic recording in photopolymer systemsoccurs through a spatial pattern of photoinitiated polymerization induced by the optical interference pattern generated duringrecording. The concentration gradient in the photosensitive species that results from the patterned polymerization leads todiffusion of the unpolymerized photosensitive species and creates a compositional pattern that converts the original optical