title: Two-photon-excited luminescence in a Tb3+ -doped lithium niobate crystal pumped by a near-infrared femtosecond laser.
abstract: Blue (487.6 nm), green (544.1 nm), yellow (582.1 nm), and red (623.6 nm) upconversion (UC) luminescences are achieved in a Tb(3+)-doped lithium niobate crystal when an 800 nm femtosecond laser is loosely focused onto the sample at room temperature. The relationship between UC luminescence intensity and the pump energy indicates that a two-photon excitation process is dominant in this UC luminescence phenomenon. The Tb(3+) sensitive temperature dependence of the luminescence intensity is demonstrated via an obvious reduction of luminescence intensity with durative laser irradiation.
authors.affiliation: Center for Condensed Matter Science and Technology, Department of Physics, Harbin Institute of Technology, West Da-zhi St. 92 Harbin 150001, China.
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Li
authors.forename: Zhi-Ren
authors.initials: ZR
authors.lastname: Zheng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lü
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.forename: Wen-Zhi
authors.initials: WZ
authors.lastname: Wu
authors.forename: Wei-Long
authors.initials: WL
authors.lastname: Liu
authors.forename: Yan-Qiang
authors.initials: YQ
authors.lastname: Yang
authors.forename: Tian-Quan
authors.initials: TQ
authors.lastname: Lü