Designing plasmonic eigenstates for optical signal transmission in planar channel devices

TL;DR

This paper demonstrates how 2D plasmonic eigenmodes in crystalline cavity channel devices can be used for directional, switchable optical signal transmission at the nanoscale, advancing on-chip optoelectronic communication.

Contribution

It introduces a novel design of plasmonic channel devices supporting higher-order eigenmodes for controllable, polarization-dependent signal transmittance in the visible to infrared range.

Findings

Achieved >20dB transmittance modulation by polarization rotation

Supported delocalized higher-order plasmon resonances in crystalline cavities

Enabled controllable signal transfer over >2 μm distance

Abstract

On-chip optoelectronic and all-optical information processing paradigms require compact implementation of signal transfer for which nanoscale surface plasmons circuitry offers relevant solutions. This work demonstrates the directional signal transmittance mediated by 2D plasmonic eigenmodes supported by crystalline cavities. Channel devices comprising two mesoscopic triangular input and output ports and sustaining delocalized, higher-order plasmon resonances in the visible to infra-red range are shown to enable the controllable transmittance between two confined entry and exit ports coupled over a distance exceeding 2 $\mu$m. The transmittance is attenuated by > 20dB upon rotating the incident linear polarization, thus offering a convenient switching mechanism. The optimal transmittance for a given operating wavelength depends on the geometrical design of the device that sets the spatial and spectral characteristic of the supporting delocalized mode. Our approach is highly versatile and opens the way to more complex information processing using pure plasmonic or hybrid nanophotonic architectures.