Selective plasmon enhancement of the 1.08 μm Nd3+ laser Stark transition by tailoring Ag nanoparticles chains on a PPLN Y-cut.

Selective photoluminescence enhancement of the specific Nd(3+) Stark transition for which laser gain has been obtained in Nd(3+)/LiNbO3 is demonstrated by means of plasmonic resonances with the appropriate symmetry configuration. By using the nonpolar Y-cut of a periodically poled LiNbO3 crystal as platform for photoreduction of metallic nanostructures, periodically distributed chains of Ag nanoparticles oriented parallel to the ferroelectric c-axis are obtained. This alternative metallic nanostructure configuration supports the resonance between the localized surface plasmon and exclusively the π-polarized Stark laser line of Nd(3+) ions at 1.08 μm, while maintaining the remaining crystal field transitions unchanged. The work provides the experimental proof on how plasmonic-based optical antennas can be used to influence selectively rare earth optical Stark transitions to improve the performance of solid state laser gain media.