Enhanced blue-green-red up-conversion and 1.3-μm emission of Pr3+/Yb3+-codoped oxyhalide tellurite glasses with PbCl2 doping

We report on the blue-green-red up-conversion spectroscopic properties of Pr3+ /Yb3+ codoped oxyhalide tellurite glasses upon excitation of a conventional 980 nm laser diode (LD). Significant enhancement of the blue-green-red up-conversion emission intensity has been observed with increasing PbCl2 doping. The up-conversion intensity has a quadratic dependence on incident pump laser power, indicating a two-photon process. The population of the Pr3+ upper P-3(0) emitting level was accomplished through a combination of a ground state absorption, energy transfer and excitated state absorption. 1.3-mu m emission in the second telecom window originated from Pr3+ :(1)G(4) -> H-3(5) transition has also been investigated upon excitation at 980nm LD. The measured peak wavelength and full width at half-maximum of the fluorescent are 1335 nm and similar to 100 nm, respectively. An enhanced 1.3 mu m emission with increasing PbCl2 doping has also been observed. Codoping of Yb3+ significantly enhance both the blue-green-red up-conversion emission and 1.3-mu m emission intensity by way of a nonradiative Yb3+:2F(5 ->) Pr3+ :(1)G(4) energy transfer. (c) 2005 Elsevier Ltd. All rights reserved.