Frequency upconversion in Nd3+ doped PbO–GeO2 glasses containing silver nanoparticles.

Abstract: Infrared-to-visible frequency upconversion (UC) in Nd3+-doped PbO–GeO2 (PGO) glasses containing silver nanoparticles (NPs) was investigated. The excitation was made at 805nm, in resonance with the Nd3+ transition 4I9/2 → 4F5/2. Photoluminescence (PL) bands centered at 535nm, 600nm and 670nm were observed corresponding to the electronic transitions 4G7/2 → 4I9/2, [4G7/2 → 4I11/2, 4G5/2 → 4I9/2], and [4G7/2 → 4I13/2, 4G5/2 → 4I11/2], respectively. The quadratic dependence of the UC intensity versus the laser intensity indicates that two laser photons contribute for the emission of each upconverted photon. The results show for the first time that the nucleation of silver NPs in Nd3+-doped PGO glasses contributes to increase the UC efficiency and the PL enhancement reached ≈50% for the samples with the maximum concentration of NPs. [Copyright &y& Elsevier]