title: Simultaneous quasi-one-dimensional propagation and tuning of upconversion luminescence through waveguide effect.
abstract: Luminescence-based waveguide is widely investigated as a promising alternative to conquer the difficulties of efficiently coupling light into a waveguide. But applications have been still limited due to employing blue or ultraviolet light as excitation source with the lower penetration depth leading to a weak guided light. Here, we show a quasi-one-dimensional propagation of luminescence and then resulting in a strong luminescence output from the top end of a single NaYF4:Yb(3+)/Er(3+) microtube under near infrared light excitation. The mechanism of upconversion propagation, based on the optical waveguide effect accompanied with energy migration, is proposed. The efficiency of luminescence output is highly dependent on the concentration of dopant ions, excitation power, morphology, and crystallinity of tube as an indirect evidence of the existence of the optical actived waveguide effect. These findings provide the possibility for the construction of upconversion fiber laser.
authors.affiliation: College of Materials &Mineral Resources, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, China.|College of Science, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, China.
authors.forename: Dangli
authors.initials: D
authors.lastname: Gao
authors.affiliation: College of Materials &Mineral Resources, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, China.|College of Science, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, China.
authors.forename: Dongping
authors.initials: D
authors.lastname: Tian
authors.affiliation: College of Science, Chang'an University, Xi'an, Shaanxi 710064, China.
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an, Shaanxi 710121, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao