Effect of vapor transport equilibration and Mg doped on the luminescence of Er:LiNbO3

Luminescence properties of the congruent and vapor transport equilibration (VTE) treated Er:LiNbO3 and Er:Mg:LiNbO3 crystals were recorded at room temperature. It is observed that VTE treatment could enhance the emission intensity of Er3+ ions and doping with MgO would weaken it in the visible spectra. As a result, the luminescence intensity of Er3+ ions in the VTE treated Er:Mg:LiNbO3 crystal increased up to 2.2 times than that in the congruent Er:LiNbO3 crystal. In addition, both VTE treatment and doping with MgO result in some changes of the relative emission intensity of some peaks in the visible emission spectra. In the infrared emission spectra, the luminescence peak at 1540nm of Er3+ ions shifts towards the larger wavelength when the Er:LiNbO3 crystals were treated using VTE or doped with MgO. The changes in crystalline environment of Er3+ ions due to VTE treatment or doping with Mg2+ play a key role in these phenomena.