Improved performance of photorefractive polymers based on merocyanine dyes in a polar matrix

Recently, chromophores with a large figure-of-merit for incorporation into photorefractive polymers with low glass-transition temperature have become available. However, their rather polar nature so far limited their use in typical nonpolar photoconducting matrices due to dye aggregation. By incorporation of an additional polar compound we were able to influence this situation favorably, The material we report here has a factor 4 to 5 (2) improved index modulation amplitude (gain coefficient) compared to the best previously known materials. The material is sufficiently resistant against phase separation and operates in the near infrared at typical wavelengths of commercially available high-power laser diodes. (C) 1998 American Institute of Physics.