Diffraction limited focusing and routing of gap plasmons by a metal-dielectric-metal lens
Abstract
Passive optical elements can play key roles in photonic applications such as plasmonic integrated circuits. Here we experimentally demonstrate passive gap-plasmon focusing and routing in two-dimensions. This is accomplished using a high numerical-aperture metal-dielectric-metal lens incorporated into a planar-waveguide device. Fabrication via metal sputtering, oxide deposition, electron- and focused-ion- beam lithography, and argon ion-milling is reported on in detail. Diffraction-limited focusing is optically characterized by sampling out-coupled light with a microscope. The measured focal distance and full-width-half-maximum spot size agree well with the calculated lens performance. The surface plasmon polariton propagation length is measured by sampling light from multiple out-coupler slits.
- Publication:
-
Optics Express
- Pub Date:
- August 2015
- DOI:
- 10.1364/OE.23.021899
- arXiv:
- arXiv:1507.08691
- Bibcode:
- 2015OExpr..2321899D
- Keywords:
-
- Physics - Optics;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- doi:10.1364/OE.23.021899