Nonvolatile photorefractive spectral holography

We demonstrate nonvolatile storage of femtosecond pulses in a photorefractive LiNbO(3) crystal with recording and readout of spectral holograms at wavelengths of 460 and 920 nm, respectively. No degradation was observed after 24 h of continuous readout. We also show that we can realize the time-lens effect with our system by appropriately setting the ratio of the recording and the reconstruction wavelengths and the spectral resolution of the recording and the reconstruction processes.