Controlling solid state gain media by deposition of silver nanoparticles: from thermally-quenched to plasmon-enhanced Nd3+ luminescence

Abstract

We show the possibility of controlling the optical properties of Nd3+ laser ions by using different configurations of metallic nanoparticles (NPs) deposited on a solid state gain medium. In particular, we analyze the effect of two different silver NP arrangements on the optical properties of Nd3+ ions in LiNbO3: a two-dimensional (2D) high density and disordered Ag NP distribution and a one-dimensional (1D) long single chain of Ag NPs. We demonstrate that while the 2D disordered distribution produces a thermal quenching of the Nd3+ luminescence, the 1D single chain leads to the enhancement of the fluorescence from the 4F3/2 metastable state. The experimental data are theoretically interpreted by taking into account the different character, radiative or non-radiative, of the localized surface plasmonic modes supported by the Ag nanoparticle distributions at the excitation wavelength. The results point out the capabilities of rare earth ions as optical tools to probe the local plasmonic fields and are relevant to determine the optimal configuration of metallic arrays to improve the performance of potential rare earth ion based sub-micrometer lasers.