Quantum cutting downconversion by cooperative energy transfer from Ce3+ to Yb3+ in borate glasses

Quantum cutting downconversion (DC) involving the emission of two near-infrared (NIR) photons for each ultraviolet (UV) photon absorbed is realized in the Ce3+/Yb3+ codoped borated glasses. Upon excitation of Ce3+ ion with an UV photon at 330 nm, Yb3+ ions emit two NIR photons at 976 nm through an efficient excitation of Ce3+: 5d and subsequent cooperative energy transfer (ET) from Ce3+:5d to Yb3+:F-2(5/2). The maximum ET efficiency and the corresponding DC quantum efficiency were estimated to be 74% and 174%, respectively. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3040005]