Resonant-tunnelling-assisted crossing for subwavelength plasmonic slot waveguides

TL;DR

This paper proposes a resonant-tunnelling-assisted crossing method for subwavelength plasmonic slot waveguides, significantly reducing crosstalk and enhancing throughput, which could advance high-density nanoplasmonic circuits.

Contribution

It introduces a compact cavity-based structure utilizing resonant tunnelling to eliminate crosstalk in nanoscale waveguide crossings, with theoretical and simulation validation.

Findings

Crosstalk reduced to near zero at resonance

Throughput reaches unity on resonance

Material loss does not significantly affect crosstalk suppression

Abstract

We theoretically investigate the properties of crossing for two perpendicular subwavelength plasmonic slot waveguides. We show that, when encountering nano intersection, the crosstalk for the direct crossing is around 25%, almost same as throughout. In terms of symmetry considerations and resonant-tunnelling effect, we design compact cavity-based structures. Our results show that the crosstalk is eliminated and the throughput reaches the unity on resonance. Simulations results are in agreement with those from the coupled-model theory. When taking into account of the material loss, due to the unchanged symmetry properties of the modes, the crosstalk is still suppressed. Our results may open a way to construct nanoscale crossings for high-density nanoplasmonic integration circuits.