Locally Enhanced and Tunable Optical Chirality in Helical Metamaterials
نویسندگان
چکیده
We report on a numerical study of optical chirality. Intertwined gold helices illuminated with plane waves concentrate right and left circularly polarized electromagnetic field energy to sub-wavelength regions. These spots of enhanced chirality can be smoothly shifted in position and magnitude by varying illumination parameters, allowing for the control of light-matter interactions on a nanometer scale.
منابع مشابه
Optical Chirality Enhancement in Twisted Arrays of Plasmonic Nano-rods
An important property of electromagnetic fields, which arises from the interaction between fields and chiral molecules, is called optical chirality. By enhancing this field property, while maintaining constant input power, we are able to increase absorption of circularly polarized light by chiral molecules of a certain handedness. This enhancement is achieved through the use of achiral plasmoni...
متن کاملOn the origin of chirality in nanoplasmonic gyroid metamaterials.
Metallic single gyroids, a new class of self-assembled nanoplasmonic metamaterials, are analyzed on the basis of a tri-helical metamaterial model. The physical mechanisms underlying the chiral optical behavior of the nanoplasmonic single gyroid are identified and it is shown that the optical chirality in this metallic structure is primarily determined by structural chirality and the connectivit...
متن کاملHighly tunable optical activity in planar achiral terahertz metamaterials.
Using terahertz time domain spectroscopy we demonstrate tunable polarization rotation and circular dichroism in intrinsically non-chiral planar terahertz metamaterials without twofold rotational symmetry. The observed effect is due to extrinsic chirality arising from the mutual orientation of the metamaterial plane and the propagation direction of the incident terahertz wave.
متن کاملChiral poly(fluorene-alt-benzothiadiazole) (PFBT) and nanocomposites with gold nanoparticles: plasmonically and structurally enhanced chirality.
Materials with large chiral optical activity at visible wavelengths are of great interest in photonics, particularly as a route to chiral optical metamaterials. Here, we demonstrate the plasmonic enhancement of the chiral optical activity of chiral poly(fluorene-alt-benzothiadiazole) (PFBT) doped with gold nanoparticles. The supramolecular helical organization of polymeric chains with simultane...
متن کاملImplementation of dispersion-free slow acoustic wave propagation and phase engineering with helical-structured metamaterials
The ability to slow down wave propagation in materials has attracted significant research interest. A successful solution will give rise to manageable enhanced wave-matter interaction, freewheeling phase engineering and spatial compression of wave signals. The existing methods are typically associated with constructing dispersive materials or structures with local resonators, thus resulting in ...
متن کامل