Achieving a high-Q response in metamaterials by manipulating the toroidal excitations

The excitation of toroidal multipoles in metamaterials is investigated for a high- Q response at a subwavelength scale. In this paper, we explore the optimization of toroidal excitations in a planar metamaterial comprised of asymmetric split ring resonators (ASRRs). It is found that the scattering power of a toroidal dipole can be remarkably strengthened by adjusting the characteristic parameter of ASRRs: an asymmetric factor. Interestingly, the improvement in toroidal excitation accompanies an increment of the Q factor of the toroidal metamaterial; it is shown that both the scattering power of the toroidal dipole and the Q factor increase more than one order by changing the asymmetric factor of ASRRs. The optimization in the excitation of a toroidal multipole provides an opportunity to further increase the Q factor of the metamaterial and boost light-matter interactions at the subwavelength scale for potential applications in low-power nonlinear processing and sensitive photonic applications

Graphene Plasmonics: A Platform for 2D Optics

2D optics is gradually emerging as a frontier in modern optics. Plasmons in graphene provide a prominent platform for 2D optics in which the light is squeezed into atomic scale. This report highlights some recent progresses in graphene plasmons toward the 2D optics. The launch, observation, and advanced manipulation of propagating graphene plasmons for 2D optical circuits are described. Representative achievements associated with graphene metasurfaces, challenges, recent progresses like photoexcited graphene metasurfaces, and the transformation optics linking 2D to bulk optics with singularity are investigated

Bi/Bi2O3 sensor for quantitation of dissolved oxygen in molten salts

Abstract To quantify the oxygen content in molten salts, we examined the performance of an yttria-stabilized zirconia solid electrolyte oxygen sensor with a Bi/Bi2O3 reference electrode, focusing on its output accuracy. When the above sensor was tested in a flow of gas with known oxygen partial pressure, $$p_{O_2}$$ p O 2 , a linear relationship between $$lgp_{O_2}$$ l g p O 2 and the electromotive force (EMF) was observed, and the correlation slope exhibited a positive deviation from Nernstian behavior. EMF measurements performed in molten NaCl–KCl indicated that the oxygen content of this salt mixture increased with increasing oxygen partial pressure in the covering gas, in agreement with Henry’s law. Moreover, the EMF exhibited a linear decrease with increasing melt temperature of molten NaCl–KCl, in agreement with the theoretical model. Finally, a relationship between the structure of molten NaCl–KCl and its oxygen diffusion behavior was established. As a result, the developed sensor was demonstrated to be well suited for determining the oxygen content of molten salts

Achieving a high-Q response in metamaterials by manipulating the toroidal excitations

The excitation of toroidal multipoles in metamaterials is investigated for a high- Q response at a subwavelength scale. In this paper, we explore the optimization of toroidal excitations in a planar metamaterial comprised of asymmetric split ring resonators (ASRRs). It is found that the scattering power of a toroidal dipole can be remarkably strengthened by adjusting the characteristic parameter of ASRRs: an asymmetric factor. Interestingly, the improvement in toroidal excitation accompanies an increment of the Q factor of the toroidal metamaterial; it is shown that both the scattering power of the toroidal dipole and the Q factor increase more than one order by changing the asymmetric factor of ASRRs. The optimization in the excitation of a toroidal multipole provides an opportunity to further increase the Q factor of the metamaterial and boost light-matter interactions at the subwavelength scale for potential applications in low-power nonlinear processing and sensitive photonic applications.</p

Graphene Plasmonics: A Platform for 2D Optics

2D optics is gradually emerging as a frontier in modern optics. Plasmons in graphene provide a prominent platform for 2D optics in which the light is squeezed into atomic scale. This report highlights some recent progresses in graphene plasmons toward the 2D optics. The launch, observation, and advanced manipulation of propagating graphene plasmons for 2D optical circuits are described. Representative achievements associated with graphene metasurfaces, challenges, recent progresses like photoexcited graphene metasurfaces, and the transformation optics linking 2D to bulk optics with singularity are investigated.</p