Domino plasmons for subwavelength terahertz circuitry

Abstract

A new approach for the spatial and temporal modulation of electromagnetic fields at terahertz frequencies is presented. The waveguiding elements are based on plasmonic and metamaterial notions and consist of an easy-to-manufacture periodic chain of metallic box-shaped elements protruding out of a metallic surface. It is shown that the dispersion relation of the corresponding electromagnetic modes is rather insensitive to the waveguide width, preserving tight confinement and reasonable absorption loss even when the waveguide transverse dimensions are well in the subwavelength regime. This property enables the simple implementation of key devices, such as tapers and power dividers. Additionally, directional couplers, waveguide bends, and ring resonators are characterized, demonstrating the flexibility of the proposed concept and the prospects for terahertz applications requiring high integration density.

Guiding, bending, and splitting of coupled defect surface modes in a surface-wave photonic crystal

“…On the other hand, electromagnetic modes supported on periodically textured metal surfaces, which are commonly termed as spoof (or designer) surface plasmons [10][11][12][13][14][15][16][17][18][19][20][21][22] , possess spatial scales typically much smaller than the wavelength. In particular, some structured metal surfaces exhibit a complete photonic bandgap where no surface guided modes are permitted [23][24][25][26] .…”

“…Compared with conventional waveguides of spoof surface plasmons [10][11][12][13][14][15][16][17][18][19][20][21][22] which generally suffer from scattering and crosstalk when packed densely, this coupled-defect surface waveguide (CDSW) is achieved through weak coupling between otherwise tightly localized surface defect cavities, which allows shaping the flow of surface waves almost as will 30 with minimal crosstalk.…”

Conformal surface plasmons propagating on ultrathin and flexible films

“…Although some designs based on metal wires or strips are able to support surface leaky modes that have some degree of lateral confinement at terahertz frequencies (12,13), the concept of plasmonic metamaterials has proven very useful in the production of highly confined surface electromagnetic (EM) waves at low frequencies (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27). Early work in this area can be traced back to the 1950s and 1960s, when corrugated metal structures were used to generate surface EM waves at microwave frequencies (14,15).…”

“…Early work in this area can be traced back to the 1950s and 1960s, when corrugated metal structures were used to generate surface EM waves at microwave frequencies (14,15). Generally, plasmonic metamaterials consist of metal surfaces decorated with 1D arrays of subwavelength grooves, 2D arrays of subwavelength holes/dimples, or 3D metal wires in which a periodic array of radial grooves is drilled (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Recently, an alternative "spoof" SPP structure using complementary split-ring resonators as the unit cell elements has been proposed theoretically (27).…”

Reshaping Electromagnetic Emissions With Meta-Substrate Based on Spoof Plasmons

“…It has been shown recently that the dispersion relation of surface waves in ultrathin and flexible films is practically identical to the relation provided by corrugated surfaces [13,14]. Here, we propose to take advantage of this phenomenon to go toward a two-dimensional structure.…”