Tunable plasmonic devices by integrating graphene with ferroelectric nanocavity

TL;DR

This paper demonstrates a method to tune graphene plasmon resonances using ferroelectric nanocavity arrays, enabling dynamic control of plasmonic properties for advanced photonic devices.

Contribution

It introduces a novel approach to excite and tune graphene surface plasmons via ferroelectric nanocavities and applied gate voltages, combining experimental and theoretical insights.

Findings

Graphene plasmons can be excited by incident light in ferroelectric nanocavities.

Resonance frequencies are tunable from ~720 to ~1000 cm-1 by nanocavity scaling.

Resonance frequencies are tunable from ~540 to ~780 cm-1 by gate voltage.

Abstract

Graphene plasmons are able to become the fundermental of novel conceptual photonic devices, resulting from their unique characteristics containing excitation at room temperature and tunable spectral selectivity in different frequencies. The pursuit of efficiently exciting and manipulating graphene plasmons is necessary and significant for high-performance devices. Here, we investigate graphene plasmon wave propagating in ferroelectric nanocavity array. We experimentally show that the the periodic ferroelectric polarizations could be used for doping graphene into desired spatial carrier density patterns. Based on a theoretical model that considers periodic ununiform conductivity across graphene sheet, the simulation results show surface plasmon polaritons (SPP) in graphene can be excited by an incident light in a similar way to the excitation of photonic crystal resonant modes. The graphene SPP resonance can be tuned from ~720 to ~1 000 cm-1 by rescaling the ferroelectric nanocavity array, and from ~540 to ~780 cm-1 by dynamically changing the applied gate voltage. Our strategy of graphene carrier engineering to excite SPP offers a promissing way for large-scale, non-destructive fabrication of novel graphene photonic devices.