Examining the Spectroscopic and Thermographic Qualities of Er 3+ -doped Oxyfluoride Germanotellurite Glasses.

Novel ternary fluoro-germano-tellurite (GTS) glasses doped with Er ions with 0.5 mol% and 1.0 mol% were fabricated by a conventional melt and quenching method and investigated using methods of optical spectroscopy. The room-temperature absorption spectrum was recorded and analyzed to determine radiative transition rates, radiative lifetimes, and branching ratios of Er luminescence. Decay curves of Er luminesccence were recorded and analyzed. Temperature dependences of emission spectra and absorption spectra in the region from RT (room-temperature) up to 675 K were studied in detail. The contribution of competing radiative and nonradiative processes to the relaxation of luminescent levels of Er was assessed. Absolute and relative sensitivity were established utilizing the comprehensive model based on thermally coupled H/S excited states of erbium. The high quantum efficiency of the first erbium-excited state and value of gain coefficient indicate that GTS:Er glass system can be considered as conceivable NIR (near infrared) laser material as well.