Intense four- and five-photon ultraviolet upconversion processes through sensitization of Tm3+ ions in transparent SiO2-Al2O3-NaF-YF3 glass ceramics triply doped with Tm3+/Yb3+/Nd3+ under 796nm excitation were investigated. Judd-Ofelt analyses evidenced the incorporation of rare-earth ions into the precipitated β-YF3 nanocrystals. In contrast with the triply doped one, no ultraviolet upconversion luminescence was observed in the Tm3+/Nd3+ codoped glass ceramic, indicating that Yb3+ acts as bridging ions to enhance the energy transfer efficiency between Nd3+ and Tm3+. Based on the pumping power dependence of luminescence, upconversion mechanisms were proposed.
© 2007 Optical Society of America
Original Manuscript: July 27, 2007
Revised Manuscript: August 30, 2007
Manuscript Accepted: September 18, 2007
Published: October 15, 2007
Daqin Chen, Yuansheng Wang, Yunlong Yu, Feng Liu, and Ping Huang, "Sensitized thulium ultraviolet upconversion luminescence in Tm3+/Yb3+/Nd3+ triply doped nanoglass ceramics," Opt. Lett. 32, 3068-3070 (2007)