Holographic and Thermal-Fixing Characteristics of Doubly Doped Zn:Fe:LiNbO₃ Crystals

We perform a comprehensive experimental study on holographic and thermal-fixing characteristics of Zn:Fe:LiNbO₃. The measured hologram decay time constants, respectively caused by optical readout and under dark condition, with thermal fixing are 15 times and 75 times longer than that obtained without thermal fixing. This suggests that Zn:Fe:LiNbO₃ crystals are suitable for thermal fixing. Multiplexed recordings of 300 holograms using different thermal fixing schemes verify that a proper multiplexing scheme such as track-division thermal-fixing scheme for disc-type holographic storage can effectively compensate for the negative effect of zinc-doping on the dynamic range, thus the storage density is enhanced.