title: Three-photon indirect sensitization in green upconversion luminescence of Er/Tm codoped NaY(WO(4))(2) crystal.
abstract: Upconversion spectra of Er/Tm codoped NaY(WO(4))(2) crystal excited by 974nm laser is investigated. Intensive 520nm/550nm and 800nm emissions are observed. Three-photon process at high pumping power is presented in the green upconversion. A model is proposed that the three-photon process is actualized by the energy indirect sensitization between two Er(3+) ions and one Tm(3+) ion, via excited state absorption and two cross relaxations. Two Er(3+) ions totally absorb three 974nm photons, emitting one green photon, and Tm(3+) ion plays the role of temporary energy storage in this process.
authors.forename: Kang
authors.initials: K
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Lin
authors.initials: L
authors.lastname: Han
authors.forename: Jing
authors.initials: J
authors.lastname: Liang
authors.forename: Xuezhi
authors.initials: X
authors.lastname: Zhang
authors.forename: Lihua
authors.initials: L
authors.lastname: Yan
authors.forename: Jianguo
authors.initials: J
authors.lastname: Tian
authors.forename: Jingjun
authors.initials: J
authors.lastname: Xu