Mechanism of quantum cutting in Pr3+-Yb3+ codoped oxyfluoride glass ceramics

Quantum cutting of 0.44 mu m photon into 1.0 mu m and 1.3 mu m photons was demonstrated in Pr3+-Yb3+ codoped oxyfluoride glass ceramics by spectroscopic investigation from blue to near-infrared region. The Pr3+-Yb3+ codoped sample showed energy transfer (Pr3+:P-3(0)->(1)G(4))->(Yb3+:F-2(5/2)<- F-2(7/2)). Both under 0.44 mu m and 0.94 mu m excitations, the codoped sample showed Pr3+:(1)G(4)-> H-3(4) luminescence at 1.3 mu m, as well as Yb3+:F-2(5/2)-> F-2(7/2) luminescence at 1.0 mu m. The relative intensity of (Pr3+:1.3 mu m/Yb3+:1.0 mu m) by 0.44 mu m excitation was much higher than that by 0.94 mu m excitation. The mechanism of downconversion was proposed as a quantum cutting process by one-step energy transfer (Pr3+:P-3(0)->(1)G(4))->(Yb3+:F-2(5/2)<- F-2(7/2)), which results in generation of two near-infrared photons via the Pr3+:(1)G(4)-> H-3(5) and Yb3+:F-2(5/2)-> F-2(7/2) transitions. (C) 2012 Elsevier B.V. All rights reserved.