Control of diffraction from permanent gratings in dye doped liquid crystals

Summary form only given. Photorefractive-like liquid crystals are one of the most efficient optical nonlinear materials developed so far. Their thin film format (typically between 10-25 /spl mu/m), ideal for integrated optics applications, is accompanied by large diffraction efficiencies and high coupling coefficients.We observed that permanent gratings can be created in dye-doped photorefractive liquid crystals and their diffraction efficiency controlled by electric field. The gratings were written in 12 /spl mu/m thick 5CB liquid crystal cells doped with a relatively high concentration (above 1%) of a methyl red dye.