Growth and spectral properties of Er 3+ /Tm 3+ co‐doped LiYF 4 single crystal

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.