Theoretical studies on non-volatile holographic recording for LiNbO3:Cu:Ce crystal

• We get the value of the total space charge of LiNbO3:Cu:Ce.
• Direct electron exchange between the Cu+/Cu2+ and Ce3+/Ce4+ centres due to the tunnelling effect dominates the charge transfer process.
• The nonvolatile holography performance in the near-stoichiometric LiNbO3:Fe is much better than that in the LiNbO3:Cu:Ce.

We have conducted a theoretical study of steady-state, non-volatile, two-step, two-colour holographic recording performance of LiNbO3:Cu:Ce on the basis of the two-centre model (the deep-trap and shallow-trap centres are Cu+/Cu2+ and Ce3+/Ce4+, respectively). The results show that direct electron exchange between the Cu+/Cu2+ and Ce3+/Ce4+ centres due to the tunnelling effect dominates the charge transfer process during non-volatile, two-step, two-colour holography and determines the two-step, two-colour holography performance in LiNbO3:Cu:Ce. We have further compared the performance of the two-step, two-colour holography in LiNbO3:Cu:Ce with that of near-stoichiometric LiNbO3:Fe. It is shown that, in terms of the total space charge field, the non-volatile two-step, two-colour holography performance of near-stoichiometric LiNbO3:Fe is much better than that of LiNbO3:Cu:Ce within the intensity range reachable by continuous-wave lasers.