,Blue Upconversion Luminescence in Tm3+/Yb3+ Codoped CaWO4 Polycrystals

• 作 者: XU Yan-Ling WANG Yun-Long SHI Lian-Sheng TAN Xiang
• 机 构: Department of Chemistry, Harbin Institute of Technology, Harbin 150001“,”Department of Material and
• 出 处: 中国物理快报（英文版）
• 发表日期: 2013年8期

We investigate the upconversion emission of CaWO4:Tm3+ /Yb3+ polycrystals prepared by the high-temperature solid-state method.The crystal structure of the polycrystals is characterized by means of x-ray diffraction.Under the excitation of a 98Onm continuous wave diode laser,the samples show intense blue upconversion emissions centered at 473nm,corresponding to the 1G4→3H6 transition of Tm3+.The dependence of the upconversion emission intensity on the pump power of a laser diode is measured,and the results indicate that the two-photon and three-photon processes contribute simultaneously to the blue upconversion emissions.The possible multiphoton upconversion process and upconversion mechanisms are discussed.