Two-color nonvolatile holographic recording and light-induced absorption in Ru and Fe codoped LiNbO3 crystals

The properties of a light-induced absorption and two-color recording were investigated in three kinds of Ru and Fe codoped LiNbO3 crystals with different Fe concentrations. A nonvolatile hologram could be recorded at a wavelength of 633 nm when blue light was simultaneously incident on the crystal. The characteristic feature of these crystals is a high persistence factor β, i.e., small loss of the hologram strength at the beginning of the readout process. The sensitivity and the dynamic range increased with increasing Fe concentration, and a high sensitivity of 0.12 cm/J and a large dynamic range of 0.53 were obtained in a 0.5 mm-thick crystal. The recording model of the nonvolatile hologram is discussed from the results of light-induced absorption measurements.