Recording Speed and Determination of Basic Materials Properties

Light deflection and modulation through dynamic evolution of photoinduced waveguides

“…The stronger initial spatial splitting for the higher fields can be easily recognized, in agreement with the experimental observations. It has to be noted, that for materials with short diffusion lengths, such as our SBN crystal, the photorefractive response time is a decreasing function of the electric field [18]. Therefore, the same normalized time corresponds to an earlier "real" time for the case of a large field than for the case of a low field.…”

“…Here the dimensionless time t has been normalized to the value of the photorefractive response time τ PR for a normalized intensity equal to 1; τ PR depends principally on the conductivity and on the dielectric properties of the crystal [18]. The physical model underlying Eqs.…”

Anisotropic build-up of photo-induced waveguides in biased photorefractive media

“…Note that the upper axis in Fig. 8 crystal was estimated by observing the dynamics of erasure of photorefractive holographic gratings recorded at small interfering angles in the same crystal and for x-oriented charge transport [21]. It was found that T d ≈ 4400/I tot in the range of intensities used for our waveguide experiments.…”

“…The whole procedure is repeated at each temporal steps ∆t until the final time. A normalized time τ is defined by τ = t/T d where T d is the (x-oriented) dielectric response time of the material under illumination [21] given as…”