Upconversion emission in antimony-germanate double-clad optical fiber co-doped with Yb3+/Tm3+ ions

摘要

In the paper upconversion luminescence properties in Yb3+/Tm3+ co-doped antimony-germanate glass and double-clad optical fiber were studied. The concentration of lanthanides, which has shown the highest upconversion emission intensity at 478 nm ((1)G(4) -> H-3(6)) and 650 nm ((1)G(4) -> F-3(4)), is 1Yb(2)O(3)/0.1Tm(2)O(3) (mol%) as a result of exciting with a laser diode (976 nm). The lifetime of F-2(5/2) (Yb3+) level decreases from 781 mu s to 71 mu s in the presence of Tm3+ 0.1-0.75 mol% respectively. Luminescence decay curve of glass co-doped with 1Yb(2)O(3)/0.75Tm(2)O(3) suggests donor-donor fast migration followed by Tm3+ -> Yb3+ energy transfer. Glass characterized by highest intensity of upconversion luminescence (1Yb(2)O(3)/0.1Tm(2)O(3) mol%) was used as core of double-clad optical fiber made by modified rod-in-tube method. Mechanisms influencing differences in upconversion amplified spontaneous emission of the fabricated optical fiber and bulk glass were discussed. Reabsorption of the amplified spontaneous emission signal along the fibre resulting from Tm3+:H-3(6) -> (1)G(4), transition was observed. (C) 2014 Elsevier B.V. All rights reserved.