Ho3+ sensitized upconverted emission from Er3+ doped TeO2 glass system

The energy transfer between two similar rare earth ions (Ho3+↔Er3+) doped in lithium tellurite glass has been studied. The change in fluorescence emission and the lifetime of the donor and acceptor involved in the energy transfer has been measured by varying the concentrations of Ho3+ (donor), keeping the Er3+ (acceptor) concentration fixed. It is found that the intensity of Er3+ bands increases on increasing the Ho3+ concentration. The lifetime of the Er3+ levels involved in transition also increases simultaneously. The probability of energy transfer and its quantum efficiency has also been studied.