Spectroscopic Analysis of Er3+ Transitions in Zr/Er:LiNbO3 Crystal

The effect of the new optical damage resistant Zr4+ ion on the optical characteristics of Er3+ ion in Zr/Er:LiNbO3 crystal grown by the Czochralski technique was investigated. The near infrared emission and the fluorescence decay spectra showed that codoping with Zr4+ ions enhanced the intensity of 1.54 mu m emission and lengthened the 1.54 mu m lifetime in Er:LiNbO3 crystal. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the segregation coefficient of the doped ion. The spectroscopic properties of Zr/Er:LiNbO3 crystal based on Judd-Ofelt theory were obtained, Omega(2) = 9.08 x 10(-20) cm(2), Omega(4) = 2.00 x 10(-20) cm(2) and Omega(6) = 0.24 x 10(-20) cm(2), respectively, and the fluorescence branching ratio beta and radiative lifetime tau(rad) were discussed. A drastically lengthening radiative lifetime of 1.54 mu m emission was observed in Zr/Er:LiNbO3 crystal. It is likely that such lengthening 1.54 mu m lifetime arose from a combining effect of the complete disappearance of the Nb-Li(4+) antisites, the proximity between the chemistry element Zr and Nb, and a fast nonradiative relaxation process of (4)vertical bar(11/2) -> (4)vertical bar(13/2) transition of Er3+ ion. Fuchtbauer-Ladenburg and McCumber were used to calculate the emission cross-section at the wavelength of 1.54 mu m, and the gain cross-section spectrum of Zr/Er:LiNbO3 crystal was also studied.