ABSTRACT
Two low-glass transition photorefractive polymer composites were investigated in a symmetric reflection geometry. The holograms recorded in 105 mum thick devices have reached diffraction efficiencies as high as 60%. Unlike the gratings recorded in transmission geometry, holograms recorded in reflection geometry showed high angular selectivity and the Bragg condition was observed to be sensitive to the magnitude of the external bias field. We attribute this effect to poling-induced birefringence and give a theoretical analysis to describe the observed results.
ABSTRACT
The high-voltage bias required for video-rate compatible, efficient operation of a photorefractive polymer composite is reduced from 6-8 to 1.3 kV. At this low voltage, the device can hold erasable Bragg holograms with 80% efficiency in addition to having a video-rate response time. The transition of the hologram's state from thick to thin is analyzed in detail.
