Judd-Ofelt modeling, stimulated-emission cross-sections and non-radiative relaxation in Er3+:K2YF5 crystals

Judd-Ofelt(J-O) analysis of Er3+:K2YF5 crystals has been performed to evaluate the spontaneous emission probabilities, radiative lifetimes and luminescence branching ratios for Er3+ ions from the viewpoint of developing novel laser materials. The derived J-O parameters are Omega(2)=1.216, Omega(4)=0.647 and Omega(6)=0.459 x 10(-20) cm(2) for a K2Y0.9Er0.1F5 crystal. Radiative lifetimes of the I-4(13/2) and I-4(11/2) states are as long as 14.9 ms and 17.4 ms, respectively. Stimulated-emission cross-sections spectra are presented for the S-4(3/2)-> I-4(15/2), 4I(13/2 ->)(4)I(15/2) and I-4(11/2)-> I-4(13/2) transitions. The maximum sigma SE values are 1.5 x 10(-20) cm(2) at 558 nm, 0.72 x 10(-20) cm(2) at 1531 nm and 0.40 x 10(-20) cm(2) at 2705 nm,respectively. Non-radiative relaxation rates have been determined for the excited-states of Er(3+)ions in K2YF5. It is assumed that Er3+:K2YF5 crystals are promising for green up-conversion lasers. (C) 2016 Elsevier B.V. All rights reserved.