The time evolution of space-charge field gratings in photorefractive media is derived for a
simple two-level electron–hole-transport model. At one level, charge transfer occurs by …

We solve the problem of the transmission of time modulated signals in a two-beam coupling
photorefractive set-up using an absorbing material. We obtain an analytical expression that …

Solutions are obtained for the refractive index grating in a photorefractive material in which
the writing or erasing beams are short-pulse (less than tens of nanoseconds), high …

Edge enhancement, a type of optical image processing, is performed in a photorefractive
material in real time and with low incident-light intensities (10^− 3 W/cm^ 2). We calculate …

The development of a theory of four-wave mixing in photo-refractive crystals is described.
This theory is solved in the undepleted pumps approximation with linear absorption and …

Solutions to the band-transport equations are developed to include effects on the amplitude,
dynamics, and spatial-frequency response of the space-charge field when periodic or dc …

The photorefractive properties of semi-insulating AlGaAs–GaAs multiple quantum wells are
described for the transverse Franz–Keldysh geometry with the electric field in the plane of …

A new kind of optical self-defocusing is described that in steady state is independent of
optical beam power and is strongly asymmetric. The physical mechanism responsible is the …

We report on the synthesis and the optical characterization of a photorefractive sol-gel
material which contains nonlinear azo chromophore and carbazole charge transporting …

Two coherent light beams can couple in any absorbing material owing to a light-induced
modulation of the material's dielectric constant. In photorefractive crystals the coupling …