Holographic scattering as a technique to determine the activation energy for thermal fixing in photorefractive materials

We introduce holographic scattering as a technique to determine the activat ion energy for thermal fixing of refractive index patterns in photorefracti ve crystals. After recording a parasitic hologram at ambient temperature, w e measured the time dependence of the transmitted intensity at the fixing t emperature, to determine the time constant. The temperature dependence of t he latter allowed us to evaluate the thermal activation energy. For compari son, we performed an equivalent experiment employing the standard two-wave mixing method. The values obtained using the two techniques agree very well . (C) 2001 American Institute of Physics.