title: Ultraviolet upconversion fluorescence from 6D(J) of Gd3+ induced by 980 nm excitation.
abstract: Ultraviolet upconversion emissions of 246.2 and 252.8 nm from (6)D(J) levels of Gd(3+) ions were observed in GdF(3): 10% Yb(3+), 0.7% Tm(3+) nanocrystals under 980 nm excitation from a laser diode. The (6)D(J) levels of Gd(3+) ions can be efficiently populated by energy transfer processes of Yb-->Tm-->Gd and Yb-->Gd. A six-photon upconversion process was confirmed by the dependence of 252.8 nm emission intensity on the pumping power. The upconversion mechanism in the six-photon process was discussed based on excited state absorption of Gd(3+) ions, cross relaxation energy transfer between two excited Gd(3+) ions, and energy transfer between Gd(3+) and Yb(3+) or Tm(3+) ions.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China. wpqin@jlu.edu.cn
authors.forename: Weiping
authors.initials: W
authors.lastname: Qin
authors.forename: Chunyan
authors.initials: C
authors.lastname: Cao
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Jisen
authors.initials: J
authors.lastname: Zhang
authors.forename: Daisheng
authors.initials: D
authors.lastname: Zhang
authors.forename: Kezhi
authors.initials: K
authors.lastname: Zheng
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Guodong
authors.initials: G
authors.lastname: Wei
authors.forename: Guofeng
authors.initials: G
authors.lastname: Wang
authors.forename: Peifen
authors.initials: P
authors.lastname: Zhu
authors.forename: Ryongjin
authors.initials: R
authors.lastname: Kim