Frequency upconversion luminescence from Yb+3–Tm+3 codoped PbO–GeO2 glasses containing silver nanoparticles

Abstract

Infrared-to-visible and infrared-to-infrared frequency upconversion processes in Yb3+–Tm3+ doped PbO–GeO2 glasses containing silver nanoparticles (NPs) were investigated. The experiments were performed by exciting the samples with a diode laser operating at 980 nm (in resonance with the Yb3+ transition F27/2→F25/2) and observing the photoluminescence (PL) in the visible and infrared regions due to energy transfer from Yb3+ to Tm3+ ions followed by excited state absorption in the Tm3+ ions. The intensified local field in the vicinity of the metallic NPs contributes for enhancement in the PL intensity at 480 nm (Tm3+:G14→H36) and at 800 nm (Tm3+:H34→H36).