Polarization-selective enhancement of Nd 3+ photoluminescence assisted by linear chains of silver nanoparticles

A control of the emission of Nd3+ ions by polarization-dependent plasmon modes, supported by chains of silver nanoparticles deposited on the surface of a Nd3+:LiNbO3 crystal, is demonstrated. By combining micro-fluorescence measurements with theoretical calculations based on the boundary-element method, we explain how the energy splitting between the longitudinal and transverse modes of silver nanoparticle chains produces a selective enhancement of the Nd3+ emission Stark lines: exciting radiative modes of silver nanoparticle chains with light polarized parallel to their axis produces a spectral-selective intensification of the π-character Stark transitions of Nd3+ located in the vicinity of the silver nanoparticles. The results are relevant to the design of devices for coherent generation at the nanoscale based on rare earth solid state gain media.