Optical properties of metamaterial split ring nematic colloids

Abstract

The fabrication of 3D bulk metamaterials, optical materials with sub-wavelength building blocks, is an open challenge, along with the tuning of their optical properties, such as transmissivity or exit polarization where a possible approach is to embed liquid crystalline materials into metamaterials and use their tunable birefringence. In this work, we explore using numerical modelling the photonic properties of a composite of split ring resonator colloidal particles, dispersed in nematic liquid crystal, which was optimised to enable self-assembly fully. Specifically, using generalised FDTD simulations for light propagation in birefringent profiles, we demonstrate the photonic response of single particles, 2D and 3D colloidal crystals. The material transmittance is shown to exhibit clear resonant behaviour with the resonances tunable with the birefringence in the order of ~5%. Electric and magnetic field modes emergent on the particles are shown, as affected by the surrounding nematic birefringence, both the in the slit region of the split ring resonator (SRR) particles as well as around the particles. Observed photonic response is further explained by introducing basic equivalent LC circuits. Finally, this work is aimed at developing soft and fluid metamaterials, which exhibit optical anisotropy in the photonic response as a potent mechanism for controlling the flow of light at wavelength and even sub-wavelength scales.

Nematic Order, Plasmonic Switching and Self‐Patterning of Colloidal Gold Bipyramids

“…[ 12 , 13 ] Increasing the inventory of plasmonic nematic colloids is also of interest for various designs of reconfigurable optical metamaterials. [ 37 ]…”

An integrated platform for metamaterial-based sensing and surface acoustic wave-based acoustofluidics utilising circular interdigital transducers

“…Metamaterials are artificially engineered structures that possess properties that are not readily available in the nature, for example, those designed materials having negative values of permittivity and permeability at the same time. Split-ring resonators (SRR) are among the basic building blocks of metamaterials [19][20][21] . When exposed to electromagnetic radiation, these structures can resonate due to their interaction with the radiation.…”

Realization of a multi-band terahertz metamaterial absorber using two identical split rings having opposite opening directions connected by a rectangular patch

“…3(a) and (b), we can infer that Peak A should be caused by the combined effect of LC resonance (or fundamental response) of the two SRRs. [31][32][33] Actually, some early terahertz metamaterial studies also discussed the fundamental mode or LC mode of resonant structures. [34][35][36][37][38][39] Fig.…”