Dynamics of photorefractive grating erasure in polymeric composites

Theoretical and experimental studies are presented of the dynamics of photorefractive grating erasure in polymeric photorefractive materials with hole traps. A bi-exponential decay for the rate of optical erasing of the space-charge field has been obtained by theoretical solution. The optically induced erasure rate for polymeric photorefractive materials is theoretically predicted to depend on optical intensity as a sublinear relation of I^α, in which α is dependent on the electric field. The characteristics of the traps in a photorefractive material play a key role in the dynamics of grating erasure. Experimentally studied was the dynamic process of erasing the photorefractive grating in a polymeric composite, poly-N-vinylcarbazole:fullerene:diethyl aminonitrostyrene:tricresyl phosphate. The theoretical analysis and experimental results reveal that shallow traps are dominant in this photorefractive material.