Plasmonic Antennas Hybridized with Dielectric Waveguides

Abstract

For the purpose of using plasmonics in an integrated scheme where single emitters can be probed efficiently, we experimentally and theoretically study the scattering properties of single nanorod gold antennas as well as antenna arrays placed on one-dimensional dielectric silicon nitride waveguides. Using real space and Fourier microscopy correlated with waveguide transmission measurements, we quantify the spectral properties, absolute strength, and directivity of scattering. The scattering processes can be well understood in the framework of the physics of dipolar objects placed on a planar layered environment with a waveguiding layer. We use the single plasmonic structures on top of the waveguide as dipolar building blocks for new types of antennas where the waveguide enhances the coupling between antenna elements. We report on waveguide hybridized Yagi-Uda antennas which show directionality in out-coupling of guided modes as well as directionality for in-coupling into the waveguide of localized excitations positioned at the feed element. These measurements together with simulations demonstrate that this system is ideal as a platform for plasmon quantum optics schemes as well as for fluorescence lab-on-chip applications.

Free‐space coupling of nanoantennas and whispering‐gallery microcavities with narrowed linewidth and enhanced sensitivity

“…Metal nanoparticles can act as plasmonic antennas to convert light energy between propagating and localized fields, which provides an effective route to interface nanoscale objects and free‐space light . For example, antenna arrays have been used to couple far‐field irradiation into guided light along dielectric and plasmonic waveguides . It is expected that combining the plasmonic antennas and WGM cavities can not only obtain narrowed linewidth to improve sensitivity, but also use a simple free‐space light irradiation system to facilitate operation.…”

Optical properties of two-dimensional magnetoelectric point scattering lattices

“…[5][6][7][8][9][10][11][12][13] Tailoring of the optical scattering properties may be achieved by structural design of the scatterers to control their electric and magnetic dipole polarizability, as well as by tuning their mutual optical coupling by changing their relative coordination and orientation. With recent advances in nanotechnological fabrication techniques, based on these principles, novel metasurfaces 14,15 have been demonstrated, as well as compact and on-chip compatible optical antennas, 16,17 waveguides, 18 flat lenses, 19,20 and materials with giant birefringence. 6,7,15,[21][22][23][24] Scattering experiments on metamaterials are frequently done on periodic planar arrays of scatterers with subdiffraction pitch.…”

Lasing at the band edges of plasmonic lattices

“…Indeed, Yagi-Uda phased array antennas [20][21][22][23][24], Fano resonant oligomers [25][26][27][28][29], and periodic lattices [30][31][32][33][34][35][36] are among the most practical structures not only to control field enhancement, but also to obtain a balanced tradeoff between enhancement, Ohmic loss, and directivity control for emitters. In particular, in diffractive lattices, single-particle plasmon resonances can hybridize with Rayleigh anomalies or with planar waveguide * f.koenderink@amolf.nl modes to form extended collective modes [37].…”