title: Ultraviolet upconversion fluorescence in rare-earth-ion-doped Y2O3 induced by infrared diode laser excitation.
abstract: Room-temperature ultraviolet emission of Tm(3+) ions at 298 ((1)I(6)-->(3)H(6)), 364 ((1)D(2)-->(3)H(6)), and 391 nm ((1)I(6)-->(3)H(5)) was obtained in Y(2)O(3):Yb(3+)-Tm(3+) by continuous-wave diode laser excitation of 980 nm. Power dependence analysis demonstrates that five- and six-photon upconversion processes populate the (1)D(2) and (1)I(6) states, respectively. We believe that the (1)D(2) population originates from the cross relaxation (1)G(4)+(3)F(4)-->(3)H(4)+(1)D(2) of the Tm(3+) ions, while subsequent energy transfer from Yb(3+) to Tm(3+) excites the (1)D(2) state to the upper (1)I(6) state. High multiphoton-induced ultraviolet emission is also expected for other trivalent rare-earth ions similar to Tm(3+).
authors.affiliation: Department of Physics, Harbin Institute of Technology, Harbin, China.
authors.forename: G Y
authors.initials: GY
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Somesfalean
authors.forename: Z G
authors.initials: ZG
authors.lastname: Zhang
authors.forename: Q
authors.initials: Q
authors.lastname: Sun
authors.forename: F P
authors.initials: FP
authors.lastname: Wang