Correlation between dispersivity of charge transport and holographic response time in an organic photorefractive glass

We report on photoelectric and holographic investigations of an organic pho torefractive material based on a low molar mass glass with both photoconduc tive and nonlinear optical properties. By implementing a suitable plasticiz er we obtained a composite system which shows extremely fast initial respon se times down to 450 mu s at writing beam intensities of I-write = 10.8 W/c m(2) and 2.5 ms at the canonical intensity of I-write = 1 W/cm(2). Furtherm ore, high refractive index modulations up to Delta n = 6.1 x 10(-3), long l ifetimes and high optical quality of the samples are observed. In compariso n to a second similar composite system, which was plasticized by a more pol ar dopand, we demonstrate the crucial role of this functional constituent o n the photoelectric properties. Time-of-flight measurements show a major im pact of the plasticizer on the dispersivity of charge-carrier transport. Su bsequently the buildup and decay dynamics of the photorefractive grating ar e Substantially affected. Holographic time-of-flight measurements confirm t hese observations.