Enhanced 1.5μm emission and simultaneously suppressed green upconversion emission in Er:LiNbO3 crystals heavily codoped with MgO

Abstract

Enhanced 1.5μm emission and simultaneously suppressed green upconversion emission was observed for Er(1.0mol%):LiNbO3 crystals codoped with 8mol% MgO. The heavy MgO codoping results in the lengthening of the 1.5μm emission by 11.7%. Time-resolved spectroscopy study shows that the decay trace of the green upconversion emission of the Er∕Mg codoped crystal is obviously nonexponential. These spectroscopic characteristics are associated with the lower concentration of the cluster sites of Er3+ ion, the higher nonradiative energy transfer upconversion probability, and the lower OH− content in the crystal.