Low-Loss Plasmonics with Nanostructured Potassium and Sodium–Potassium Liquid Alloys

Abstract

Alkali metals have low optical losses in the visible to near-infrared (NIR) compared with noble metals. However, their high reactivity prohibits the exploration of their optical properties. Recently sodium (Na) has been experimentally demonstrated as a low-loss plasmonic material. Here we report on a thermo-assisted nanoscale embossing (TANE) technique for fabricating plasmonic nanostructures from pure potassium (K) and NaK liquid alloys. We show high-quality-factor resonances from K as narrow as 15 nm in the NIR, which we attribute to the high material quality and low optical loss. We further demonstrate liquid Na−K plasmonics by exploiting the Na−K eutectic phase diagram. Our study expands the material library for alkali metal plasmonics and liquid plasmonics, potentially enabling a range of new material platforms for active metamaterials and photonic devices.

Plasmonic-photonic crystal hybrid devices for optical characterization

“…One way is to refine the structure, and employ PhC cavity with a higher Q factor and a plasmonic resonator with a smaller mode volume, NPoM structure is a candidate for instance [40]. Another way is to optimize the losses of the plasmonic structure [109][110][111]. Second, we could explore hybrid nano-device based on the hybridization of PhC and other nano-photonic structures, such as dielectric nano-antenna [112][113][114] and metallic-dielectric hybrid nanoantenna [115][116][117][118][119][120][121].…”

Dual Coupled Long-Range Hybrid Surface Plasmon Polariton Waveguide for Sub-Wavelength Confinement

“…The combination of traditional waveguides with SPPs can be used to design waveguides with a long transmission distance and a small effective mode area. Nowadays, there are many kinds of SPP hybrid waveguides, and their performance has been greatly improved [28][29][30][31][32][33][34][35]. But with the rapid development of optoelectronic integrated systems, the requirement for waveguides is increasing [36][37][38].…”