HIGHLY EFFICIENT PHOTOREFRACTIVE POLYMERS FOR DYNAMIC HOLOGRAPHY

The performance of recently developed highly efficient photorefractive polymers based on the photoconducting polymer host poly-(N-vinylcarbazole) is investigated, and the use of these materials as recording media in dynamic holography and other applications is evaluated. A diffraction efficiency eta approximate to 86% (limited only by absorption and reflection losses), a two-beam coupling net gain coefficient Gamma = 200 cm(-1) and light-induced refractive index modulations as high as Delta n = 7 x 10(-3) are demonstrated, Hologram growth rates of the order of 500 ms are observed with recording light intensities > 10 mW/cm(2), using either low-power laser diodes (675 nm) or a HeNe laser (633 nm). The materials show good sensitivity in this part of the spectrum. Applications such as dynamic time-average interferometry are demonstrated.