Temperature dependence of the wavelength and threshold of fiber-taper-coupled L-band Er3+-doped tellurite glass microsphere laser

We report on the temperature dependence of L-band laser emission of fiber-taper-coupled Er 3+ -doped tellurite glass microsphere. Pumping at 1480 nm instead of 975nm was used to enhance the coupling efficiency, reduce the internal thermal effect, and increase the output laser emission. The microsphere laser emission threshold increased and the emitted laser wavelength shifted with temperature. The experimental results are explained with a quasi-four-level model, showing that a significant reduction of laser threshold can be achieved at lower temperatures and higher Q values of this microsphere laser.