Up-conversion luminescence research of Er(0.5):ZBLAN material for volumetric display application when excited by 1520nm laser

摘要

The up-conversion luminescence of the ZBLAN fluoride glass Er(0.5):ZBLAN, when excited by a 1520nm semiconductor laser, is studied in this paper. The absorption and common-fluorescence spectra are also measured in order to understand the up-conversion clearly. It is found that there are seven strong up-conversion luminescence lines (406.97m,410.42 nm), (521.97m, 527.56 nm), (542.38m, 549.27 nm), (654.27m, 665.70 nm), 801.57m nm, 819.46 nm, and 840.00 nm,which can be recognized as the fluorescence transitions of (2G4F2H)9/2 → 4I15/2, 2Hll/2 → 4I15/2, 4S3/2 → 4I15/2,4F9/2 → 4I15/2, 4I9/2 → 4I15/2, (2G4F2H)9/2 → 4I9/2, and 4S3/2 → 4I13/2 respectively. Meanwhile, the small upconversion fluorescence lines 379.20 nm, 453.10 nm and 490.60 nm are the transitions of 4G11/2 → 4I15/2, 4F5/2 → 4I15/2and 4F7/2 → 4I15/2 respectively. It is interesting that the slopes of log F-logP curves, the double-logarithmic variation of up-conversion luminescence intensity F with laser power P, are different from each other for these observed up-conversion luminescence, this being valuable for the volumetric display. Comprehensive discussions find that the 4G11/2 → 4I15/2, (2G4F2H)9/2 → 4I15/2, (2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2), and 4I9/2 → 4I15/2up-conversion luminescences are five-photon, four-photon, three-photon, and two-photon up-conversion luminescences respectively. It is found also that the absorption from ground-state 4I15/2 level to 4I13/2 level is very large, which is beneficial to the sequential energy transfer up-conversion to occur.