Interfacing Dielectric-Loaded Plasmonic and Silicon Photonic Waveguides: Theoretical Analysis and Experimental Demonstration

Abstract

International audienceA comprehensive theoretical analysis of end-fire coupling between dielectric-loaded surface plasmon polariton and rib/wire silicon-on-insulator (SOI) waveguides is presented. Simulations are based on the 3-D vector finite element method. The geometrical parameters of the interface are varied in order to identify the ones leading to optimum performance, i.e., maximum coupling efficiency. Fabrication tolerances about the optimum parameter values are also assessed. In addition, the effect of a longitudinal metallic stripe gap on coupling efficiency is quantified, since such gaps have been observed in fabricated structures

Merging Plasmonics and Silicon Photonics Towards Greener and Faster “Network-on-Chip” Solutions for Data Centers and High-Performance Computing Systems

“…Taking into consideration the intrinsic TM nature of plasmonic waves, the geometrical dimensions of the Si rib waveguides need to be carefully chosen for compatibility with plasmonic waveguides. In this perspective, rib waveguides featuring a cross section of 400nm width by 340nm height with a 50nm-thick remaining slab are the Si waveguide technology of choice for the routing platform in order to support low-loss TM light propagation [37].…”

“…The design of this approach relies on numerical modeling conducted by means of full vectorial three-dimensional finite element method (3D-FEM) simulations. Towards finalizing the design specifications, various parameters should be examined, i.e., the Si waveguide's width, the vertical offset between the two types of waveguides, the existence of a longitudinal gap in the metallic stripe as usually exists in fabricated structures, so as to optimize the matching of the optical modes during transition [37]. The validity of the simulation outcomes is achieved by their comparison with cut-back measurements for a variety of fabricated all Si and hybrid Si-DLSPP waveguide samples [31], [37].…”

“…Towards finalizing the design specifications, various parameters should be examined, i.e., the Si waveguide's width, the vertical offset between the two types of waveguides, the existence of a longitudinal gap in the metallic stripe as usually exists in fabricated structures, so as to optimize the matching of the optical modes during transition [37]. The validity of the simulation outcomes is achieved by their comparison with cut-back measurements for a variety of fabricated all Si and hybrid Si-DLSPP waveguide samples [31], [37]. As a result, a coupling loss per interface variance with a mean value of -2.5dB is feasible for 175nm-wide Si waveguides with 200nm vertical offset and DLSPP waveguides with 0.5μm metal gap.…”

“…In this perspective, silicon photonics can be used for low-loss optical transmission in passive interconnection components, plasmonics can provide small footprint and low power consumption in active switching modules and electronics can be employed for intelligent decision-making mechanisms. However, considering that plasmonic technology is a premature technology with only a few years of development compared to silicon photonics and with limited functionality so far, the way towards the implementation of such hybrid NoC environments requires priorly: a) the interconnection between silicon and plasmonic waveguide structures in a SOI platform in order to avoid the employment of high-loss plasmonic waveguides for passive circuitry [30], [37], b) the proof of the credentials of plasmonics in wavelength division multiplexing (WDM) applications so as to support the complete portfolio of optics [38], c) the demonstration of functional active plasmonic circuitries in realistic data traffic environments [25], [31].…”

On-Chip Detection of Radiation Guided by Dielectric-Loaded Plasmonic Waveguides

“…Note that although tapered gratings are used for DLSPPW mode excitation with a free-propagating laser beam, in real on-chip applications, it will be more convenient to excite DLSPPW modes by other means, e.g., by coupling a DLSPPW with a photonic waveguide 29 . In such a configuration, the influence of the background photocurrent can be highly suppressed.…”