Nonresonant enhancement of the nonsteady-state holographic currents in photoconductive crystals

In this paper, we report on nonresonant excitation holographic currents in an external sinusoidal electric field with frequency /spl Omega/. We have obtained general expression for the nonsteady-state photocurrent amplitude excited in an AC electric field. Dependence of the nonsteady-state photocurrent amplitude versus the frequency of phase modulation /spl omega/ was measured in n-type photorefractive Bi/sub 12/SiO/sub 20/ crystal. We observed linear growth of the signal for low modulation frequencies up to a certain characteristic cut-off frequency and frequency-independent region for high modulation frequencies.