Photorefractive recording in LiNbO_3:Mn

The dynamic range, sensitivity, and dark decay of holographic recording of wavelength 458 nm in LiNbO(3) crystals doped with 0.2-at. % Mn with different oxidation states have been measured. The measured sensitivity is 0.5 cm/J and is found to be independent of the oxidation state, and the largest M/# obtained is 12/mm (extraordinary light polarization; light wavelength, 458 nm). This combination of very large M/# and high sensitivity is in strong contrast with results for LiNbO(3):Fe for which a direct trade-off exists between M/# and sensitivity. The activation energy of the dark decay of holograms stored in these LiNbO(3):Mn crystals is ~1.0 eV , which is characteristic of proton compensation and leads to a projected lifetime of holograms of three years at room temperature.