[3] K. Buse, A. Adibi, D. Psaltis. Non-volatile holographic storage in doubly doped lithium niobate crystals [J]. Nature, 1998, 393(6686):665～668

[5] Youwen Liu, Liren Liu, Changhe Zhou et al.. Nonvolatile photorefractive holograms in LiNbO3∶Cu∶Ce crystals [J]. Opt. Lett., 2000, 25(12):908～910

[6] De’an Liu, Liren Liu, Changhe Zhou et al.. Nonvolatile holograms in LiNbO3∶Fe∶Cu by use of the bleaching effect [J]. Appl. Opt., 2002, 41(32):6809～6811

[7] X. Yue, A. Adibi, T. Hudson et al.. Role of cerium in lithium niobate for holographic recording [J]. J. Appl. Phys., 2000, 87(9):4051～4055

[8] Youwen Liu, Liren Liu, De’an Liu et al.. Intensity dependence of two-center nonvolatile holographic recording in LiNbO3∶Ce∶Cu crystals [J]. Opt. Commun., 2001, 190:339～343

[9] Lirong Ren, Liren Liu, De’an Liu et al.. Optimal switching from recording to fixing for high difgraction efficiency from a LN∶Cu∶Ce photorefractive nonvolatile hologram [J]. Opt. Lett., 2004, 29(2):186～188