Study of optical properties of YLF:Nd:Yb:Tm crystals

In this paper we present a comparison between YLF:Yb:Tm and YLF:Yb:Tm:Nd systems identifying the most important processes that lead to an enhancement of thulium blue up conversion emission, under excitation around 792 nm, for the double sensitized system. Analysis of the 483 nm and 1030 nm emissions for the samples with different concentrations of Nd3+ ions showed that energy transfer between Nd3+ and Yb3+ is the main mechanism and is responsible for the enhancement in up-conversion.