title: Three-photon-excited upconversion luminescence of Ce(3+): YAP crystal by femtosecond laser irradiation.
abstract: Infrared to ultraviolet and visible upconversion luminescence was demonstrated in trivalent cerium doped YAlO(3) crystal (Ce(3+): YAP) under focused infrared femtosecond laser irradiation. The fluorescence spectra show that the upconverted luminescence comes from the 5d-4f transitions of trivalent cerium ions. The dependence of luminescence intensity of trivalent cerium on infrared pumping power reveals that the conversion of infrared radiation is dominated by three-photon excitation process. It is suggested that the simultaneous absorption of three infrared photons pumps the Ce(3+) ion into upper 5d level, which quickly nonradiatively relax to lowest 5d level. Thereafter, the ions radiatively return to the ground states, leading to the characteristic emission of Ce(3+).
authors.forename: Luyun
authors.initials: L
authors.lastname: Yang
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Dong
authors.forename: Danping
authors.initials: D
authors.lastname: Chen
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Ning
authors.initials: N
authors.lastname: Da
authors.forename: Guangjun
authors.initials: G
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Xiongwei
authors.initials: X
authors.lastname: Jiang
authors.forename: Congshan
authors.initials: C
authors.lastname: Zhu
authors.forename: Jianrong
authors.initials: J
authors.lastname: Qiu