title: Multiphoton-excited upconversion luminescence of Nd:YVO(4).
abstract: Fluorescence spectra of Nd:YVO(4) under excitation of a continuous wave (CW) diode laser and a femtosecond laser at 800nm were investigated. It was found that Nd:YVO(4) shows different upconversion and downconversion luminescencent behaviors when excited by the diode laser and the femtosecond laser. The dependence of the upconversion luminescence intensity on the pump power of the femtosecond laser was discussed. The populations of the upper energy levels for upconversion and downconversion luminescence were calculated based on the Bloch equations. The calculations agree well with the experimental results.
authors.forename: Xinshun
authors.initials: X
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Song
authors.forename: Haiyi
authors.initials: H
authors.lastname: Sun
authors.forename: Zhizhan
authors.initials: Z
authors.lastname: Xu
authors.forename: Jianrong
authors.initials: J
authors.lastname: Qiu