Upconversion processes and laser action in K_5Nd(MoO_4)_4 stoichiometric crystal

摘要

In this work we report the upconversion processes that produce blue, green, orange, and red emissions in K_5Nd(MoO_4)_4 stoichiometric crystal together with the dynamics and spectral properties of the laser emission. It was found that upconversion energy transfer processes reduce the energy storage capacity through the reduction of the fluorescence lifetimes of the metastable ~4F_(3/2) level. The experiments were conducted in such a way that the dynamics of the infrared and visible fluorescence was performed under lasing and nonlasing conditions. The dynamics of the upconverted emission shows that both upconversion energy transfer and excited state absorption of the laser emission occur.