title: Optical transitions of Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 glass.
abstract: Optical absorption and emission properties of the Er3+/Yb3+ codoped TeO2-WO3-Bi2O3 (TWB) glass has been investigated. The transition probabilities, excited state lifetimes, and the branching ratios have been predicted for Er3+ based on the Judd-Ofelt theory. The broad 1.5 microm fluorescence was observed under 970 nm excitation, and its full width at half maximum (FWHM) is 77 nm. The emission cross-section is calculated using the McCumber theory, and the peak emission cross-section is 1.03 x 10(-21) cm2 at 1.531 microm. This value is much larger than those of the silicate and phosphate glasses. Efficient green and weak red upconversion luminescence from Er3+ centers in the glass sample was observed at room temperature, and the upconversion excitation processes have been analyzed.
authors.affiliation: Faculty of Information Science and Engineering, Ningbo University, Zhejiang 315211, China. shenxiang_nbu@hotmail.com
authors.forename: Xiang
authors.initials: X
authors.lastname: Shen
authors.forename: Qiuhua
authors.initials: Q
authors.lastname: Nie
authors.forename: Tiefeng
authors.initials: T
authors.lastname: Xu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D004871:Erbium / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D055095:Optics and Photonics; D013053:Spectrophotometry; D013691:Tellurium / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D002412:Cations; C016774:tellurium dioxide; D004871:Erbium; C033301:bismuth oxide; D015018:Ytterbium; D013691:Tellurium; D001729:Bismuth; D014414:Tungsten