title: Generation of 1.5 μm emission through an upconversion-mediated looping mechanism in Er3+/Sc3+-codoped LiNbO3 single crystal.
abstract: Important for telecommunications, luminescence of trivalent erbium (Er) at 1.5 μm generally arises from a Stokes-shifted downconversion mechanism. We show that this luminescence following direct excitation of the 4I11/2 state is generated by upconversion-mediated looping process in Er3+/Sc3+-codoped LiNbO3 single crystal. Emissions at 1.0 and 1.5 μm from the 4I11/2 and 4I13/2 states display linear and quadratic dependences on the excitation density in two separated ranges with a threshold of 20 W/cm2. This observation correlates with two- and four-photon processes in green and red upconversion emissions. The mechanism described has implications in the improvement of the output of 1.5 μm luminescence.
authors.affiliation: School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin, China. chenguanying@hit.edu.cn
authors.forename: Guanying
authors.initials: G
authors.lastname: Chen
authors.forename: Liming
authors.initials: L
authors.lastname: Yang
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.forename: Shuwei
authors.initials: S
authors.lastname: Hao
authors.forename: Hailong
authors.initials: H
authors.lastname: Qiu
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.forename: Yuheng
authors.initials: Y
authors.lastname: Xu
authors.forename: Chunhui
authors.initials: C
authors.lastname: Yang
mesh_terms: D004871:Erbium / Q000737:chemistry*; D054023:Lasers, Semiconductor; D049449:Luminescence; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012538:Scandium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D010087:Oxides; D009556:Niobium; C091692:lithium niobate; D004871:Erbium; D012538:Scandium