Open AccessIntegrated metamaterials for efficient and compact free-space-to-waveguide coupling
Author(s) -
Bing Shen,
Peng Wang,
Randy Polson,
Rajesh Me
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.027175
Subject(s) - waveguide , optics , metamaterial , coupled mode theory , nanophotonics , bandwidth (computing) , optoelectronics , fabrication , radiation mode , coupling (piping) , slow light , robustness (evolution) , materials science , single mode optical fiber , refractive index , physics , photonic crystal , computer science , telecommunications , optical fiber , medicine , biochemistry , chemistry , alternative medicine , pathology , metallurgy , gene
We applied nonlinear optimization to design nanophotonics-based metamaterials for efficient free-space-to-waveguide coupling. Three devices were designed, fabricated and characterized. The first device couples incident light into a multi-mode waveguide, the second device couples incident light into a single-mode waveguide directly, and the third device couples and separates two orthogonal polarizations into two multi-mode waveguides. All devices offer comparable or higher coupling efficiencies, are easier to fabricate, and demonstrate higher bandwidth when compared to conventional devices. Furthermore, each device is at least an order of magnitude smaller in area than previously reported devices. The highly efficient single-mode waveguide-coupler is a unique device that has not been experimentally demonstrated before. We further performed careful simulations to underscore the tolerance of these devices to fabrication errors. Their robustness is primarily a result of the large number of coupled guided-mode resonances that are responsible for each device performance.