Enhanced photorefractive properties in Hf, Ce and Cu co-doped LiNbO3 crystals for holographic application

• Several doped LiNbO3 crystals with various level of Hf doping were grown by Cz method.
• IR peak shift is attributed to the complex defect change at different level of Hf.
• Enhanced photorefractive properties have been got with higher Hf-doping level.
• Reduced defect and increased photoconductivity are responsible for optical properties.
• 200 holograms’ experiment is realized in a coherent volume 0.073 cm3.

Hf, Ce and Cu co-doped LiNbO3 crystals with various level of Hf doping were grown in air by a conventional Cz method. The infrared spectra were measured to discuss the defect structures and the mechanism of the absorption peak shift in these crystals. The light-induced scattering of the crystals was evaluated by the transmitted light method. The influence of the Hf-doping level on the photorefractive properties of Hf, Ce and Cu co-doped LiNbO3 crystals was studied via two-beam coupling. It is found that proper doping Hf is an efficient method to enhance the comprehensive photorefractive properties of the LiNbO3. Using one of these crystals as medium, 200 holograms storage and correlation experiments based on angle fractal multiplexing have been realized in a coherent volume 0.073 cm3. Moreover the diffraction efficiency is uniform and the storage density has reached 2.2 Gb/cm3.

Correlation spots of 200 holograms in a Hf, Ce and Cu co-doped LiNbO3.Figure optionsDownload as PowerPoint slide