Angle-multiplexed hologram storage in LiNbO(3):Tb, Fe

Effect of dopant composition ratio on nonvolatile holographic recording in LiNbO3:Cu:Ce crystals

The effect of dopant composition ratio on nonvolatile holographic recording in LiNbO3:Cu:Ce crystals is investigated experimentally. The results show that the dopant composition ratio affects the recording sensitivity and fixed diffraction efficiency by altering the UV light absorption characteristics of the crystals during nonvolatile, holographic recording. Increasing the dopant composition ratio of Cu and Ce leads to an increase in the absorption of UV light and further to an increase in the recording sensitivity and fixed diffraction efficiency. The UV light absorption characteristics of LiNbO3:Cu:Ce crystals and their roles in nonvolatile holographic recording are theoretically analyzed. The theoretical results are consistent with those of the experiments.

Holographic Recording in Congruent LiNbO3 Co-Doped with Tb and Fe

We have preformed holographic recording in congruent LiNbO3 doped with Tb and Fe with a continuous-wave green laser at λ = 532 nm. This material exhibited a fast coloration upon exposure to ultraviolet (UV) light. The recording sensitivity was improved from about 0.02 cm/J to over 0.08 cm/J after UV pre-exposure, due to the increased visible absorption. Holograms recorded from the colored state could be quickly erased by UV illumination and a sequence of recording by green and erasure by UV could be continuously repeated without any noticeable degradation in maximum diffraction efficiency or sensitivity. The overall performances of this crystal relevant to holographic storage are here presented, in comparison to those obtained with near-stoichiometric LiNbO3:Tb,Fe.