Graphene Plasmons in Triangular Wedges and Grooves [component]

The ability to eectively guide electromagnetic radiation below the diraction limit is of the utmost importance in the prospect of all-optical plasmonic circuitry. Here, we propose an alternative solution to conventional metal-based plasmonics by exploiting the deep subwavelength connement and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a
more » ... , including the complete determination of their spectrum and corresponding induced potential and electric eld distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their at-graphene plasmons counterparts, but now scaled by a (purely) geometric factor in which all the information 1 about the system's geometry is contained. We believe our results pave the way for the development of novel custom-tailored photonic devices for subwavelength waveguiding and localization of light based on recently discovered 2D materials. Over the last couple of decades we have been witnessing a steady, exponential growth in the amount of information produced on a daily basis. In today's information age, huge amounts of data must be processed, stored, and delivered around the world. While the data-processing part is still primarily carried by electronics, the routing of large volumes of information is handled with photonic technologies since only these can meet the requirements in terms of high-speed, density and bandwidth. One of the greatest ambitions of modern nanophotonics 1 is to bridge the gap between electronic and photonic components, and ultimately to replace electronic circuits and processing units by their photonic-based counterparts. Current scalable photonic-based communications, however, still could not surpass the threshold towards miniaturization posed by the diraction limit. In this regard, a great deal of hope 2 has been deposited in the sub-discipline of photonics known as plasmonics, 3,4 which exploits the ability of surface plasmon-polaritons (SPPs)collective oscillations of the free-electrons at metal/dielectric interfacesto localize light into subwavelength dimensions. 58 Although the pursuit of plasmonic devices suitable for mass-production is still going on, plasmonics has already achieved some milestones, for instance, subwavelength plasmonic circuitry including waveguides, interferometers and resonators, 912 nanolasers, 1316 quantum optics with or mediated by SPPs, 1721 label-free and single molecule biochemical sensing, 2226 high-resolution nanoscopy, 27,28 and even cancer theranostics. 2931 A key component in any plasmonic circuit would be an element to transfer and guide the electromagnetic (EM) elds from point A to point B. Typical SPP-guiding struc-
doi:10.1021/acsphotonics.6b00674.s001 fatcat:fvyxrensd5cilkzohjggqasnke