Plasmonic emission enhancement from Er3+-doped tellurite glass via negative-nanobowtie

Metallic negative-nanobowtie is a new suitable structure for development of nanoantennas that can be integrated on wide number of optical devices. Nevertheless, metallic negative-nanobowtie with absence of gap deserve attention special, because in addition to present similar properties from regular nanobowtie, can also interacts with different systems, like gain materials. One of remarkable class of such material is rare earth ions, not only for the enhancement on measured intensity, but also its easiness to implement it on glasses, which constitute the main type of substrate adopted on plasmonic structures. In this work we performed the analysis of effects due implementation of erbium (Er3+) rare earth ions into tellurite glass over a pattern of negative-nanobowtie on absence of gap between its tips, fabricated by focused ion beam (FIB) technique from gold (Au) films with 240 nm thickness. Here, the negative-nanobowties are vertically excited by an argon laser (Ar) at 488 nm and were performed to verify the dependence of nanobowtie’s geometry over the electric field along its symmetry axis. An asymptotic energy gap between the localized surface plasmon polariton modes and the ion spectral position was observed, which couple strongly with the 2H11/2→4I15/2 radiative emission of the Er3+. Besides, the 4S3/2→4I13/2 electronic transition is an indirect transition that was improve due to negative-nanobowtie in comparison with the 4I9/2→4I15/2.