Investigation for the high recording sensitivity with two center recording in LiNbO 3 :Fe:Ru crystals

Abstract

LiNbO 3 :Fe:Ru crystal is the effective recording media with high recording sensitivity for two-center recording, and the physical mechanism for the high recording sensitivity is investigated theoretically and experimentally. The results show that the energy level of Ru perhaps is closer to that of Fe than that of Mn in LiNbO 3 crystal, the electrons in Ru center can be excited more effectively into the conduction band in the same sensitizing conditions, which can induce the improvement of the recording sensitivity. The recording sensitivity 0.044cm/J in LiNbO 3 :Fe:Ru crystal, which is ten times larger than that obtained in LiNbO 3 :Fe:Mn reported early. However, the elevation of energy level of deep center will induce that the electron excitation from deep center by the recording light become more effective, and the persistence decreases with the recording sensitivity increase, the grating in Ru center can be erased by red light obviously.In practical application people must take a trade off between the recording sensitivity and persistence.

Investigation on the OH^− absorption and blue photorefractive properties in Zr:Ru:Fe:LiNbO_3 crystals as a function of Li composition

“…From then on, other materials such as Cu:Ce:LiNbO 3 and Cu:Fe:LiNbO 3 crystals were successively reported to have similar properties [3,4]. Recently, it was demonstrated that Ru:Fe:LiNbO 3 crystal was another excellent medium for such applications [5]. However, the substantial Li deficiency in the nominally congruent Ru:Fe:LiNbO 3 crystal introduces some poor photorefractive properties such as strong optical damage and low recording sensitivity to hinder the utilization of the crystal in commercial applications.…”