Furnace-melt, multi-component glasses are used to produce dense gain media for waveguide and micro-chip lasers. The compositional flexibility is often accompanied by elevated water contents, which can lead to hydroxyl (OH) quenching. OH quenching can significantly shorten excited state lifetimes, even at low pump powers. It therefore becomes important to know and control the OH content of laser glasses. While a simple relation between infrared vibration spectra and OH contents exists for vitreous silica, we show that this relation does not apply to multicomponent glasses. Instead, we present a self-consistent calculation to determine an order- of-magnitude estimate of the number of quenched rare-earth (RE) ions in multi-component glasses. Infra-red absorption spectra and fluorescence lifetimes are required. This method gives an accurate prediction of quench-shortened fluorescent lifetimes in a wide variety of host glasses.
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