Sensitizing effect of Yb3+ ions on photoluminescence properties of Er3+ ions in lead phosphate glasses: Optical fiber amplifiers

Abstract The Er 3+ /Yb 3+ -codoped lead phosphate (PPbKANErYb) glasses have been prepared by using melt quenching technique and characterized through spectroscopic studies such as absorption, emission, decay and upconversion measurements. An intense near-infrared (NIR) emission at 1.53 μm was observed which has been explained based on the effective energy transfer from Yb 3+ to Er 3+ ions. The absorption ( 4 I 15/2  →  4 I 13/2 ) and emission cross-section ( 4 I 13/2  →  4 I 15/2 ) of 1.53 μm emission band was calculated and found to be of the order of 6.76 × 10 −21 and 7.9 × 10 −21 cm 2 , respectively, by using the McCumber theory. The PPbKANErYb glasses exhibit higher luminescence intensity (more than 3 times) and full width at half maxima (55 nm) compared to 1.0 mol % Er 3+ singly doped glass (50 nm). All the decay curves of the 4 I 13/2 level exhibited single exponential nature and the lifetimes increased (1760, 1776, 1942 and 2830 μs) with the increase of Yb 2 O 3 (0.5, 1.0, 2.0 and 3.0 mol %) concentration. Intense red band at 670 nm corresponding to 4 F 9/2  →  4 I 15/2 transition and green emission bands at around 530 and 555 nm corresponding to 2 H 11/2  →  4 I 15/2 and 4 S 3/2  →  4 I 15/2 , transitions, respectively, have been observed under the excitation of 980 nm. The intensity of the upconversion emissions is found to be increased with the increase of Yb 3+ ion concentration and its mechanism have been explained. The luminescence decay curves of the 4 S 3/2  →  4 I 15/2 upconversion luminescence of Er 3+ /Yb 3+ codoped PPbKAN glasses under the infrared excitation of 980 nm have been evaluated. The results reveal that the investigated glasses might be potential candidates for optical fiber amplifiers/laser sources at 1.55 μm band.