Two-step holographic recording in photorefractive lithium niobate crystals using ultrashort laser pulses

We investigate non-volatile holographic data storage in photorefractive lithium niobate crystals. Infrared picosecond laser pulses are used to write holograms after sensitizing the crystal with blue light from a cw-laser. The dependence of the dynamic range and the photoconductivity on the pulse intensities and the recording wavelength is investigated in detail. The results can be explained by a two-center model if the mean intensity of the laser pulses is considered. We demonstrate that several fixed holograms can be multiplexed by employing the wavelength multiplexing technique.