Growth and spectral properties of Er~(3+)/Tm~(3+) co-doped LiYF_4 single crystal

摘要

High quality Er~(3+)/Tm~(3+):LiYF_4 single crystals were grown by a Bridgman method. The absorption spectra and luminescent properties of the crystals were studied to characterize the effect of Tm~(3+) on the spectroscopic properties upon excitation of an 800 nm laser diode. The broaden 1.5 μm and the enhanced 2.7 μm emission were observed in the Er~(3+)/Tm~(3+) co-doped LiYF_4 single crystals. Meanwhile, the up-conversion and 1.5 μm emission intensities from Er~(3+) decrease with increasing the ratio of Tm~(3+) to Er~(3+). The energy transfer processes between Tm~(3+) and Er~(3+) in the Er~(3+)/Tm~(3+) co-doped samples were analyzed. The energy transfer efficiency η_(ETE) from Er~(3+) to Tm~(3+) is calculated. The highest η_(ETE) of 65.30% for the sample with 0.296 mol% of Er~(3+), 0.496 mol% of Tm~(3+) concentration was obtained. The present work indicates that Er~(3+)/Tm~(3+) co-doped LiYF_4 single crystal can be a promising material for the potential application in infrared devices.