Luminescence properties of Er3+/Nd3+ co-doped Na5Lu9F32 single crystals for 2.7 mu m mid-infrared laser

摘要

The enhanced 2.7 mu m mid-infrared emission from the Er3+:I-4(11/2) -> I-4(13/2) transition with Nd3+ ions as the sensitizer was achieved in the Na5Lu9F32 single crystal which was successfully grown by a Bridgman method. The transmission spectrum was tested and almost no absorption of 2.7 mu m band was observed. It was indicated that the content of OH-ion was very low in the crystal and it was beneficial to the 2.7 gm mid-infrared laser output. Intense 2.7 mu m emissions were achieved with Nd3+ ions sensitizing Er3+ ions under the 800 nm LD pumping and the energy transfer processes between Er3+ and Nd3+ ions were analyzed. Meanwhile, the greatly decreased near infrared emission at 1.5 gm and green up-conversion emission were obtained. Additionally, the optimized concentration ratio of Er3+ to Nd3+ for efficient 2.7 gm emission was investigated in this work and the maximum emission cross section at 2.7 mu m was calculated. The decay curve of 1.5 mu m emission could be well fitted by Inokuti-Hirayama expression, which was strongly indicated the dipole-dipole energy transfer from Er3+ to Nd3+ ions. The results showed that Er3+/Nd3+ co-doped Na5Lu9F32 single crystal had potential applications in 2.7 mu m mid infrared laser. (C) 2017 Elsevier B.V. All rights reserved.