We study the physical origin of extreme optical chirality of subwavelength arrays of chiral holes in metal. We reconstruct the nanoscale relief of the hole arrays by the atomic-force microscopy and post-process the data to acquire an average unit-cell shape clear of noise and defects. For this shape, we perform the electromagnetic finite difference time domain simulations that reproduce all important features observed by the light-transmission experiments, including the notably strong circular dichroism and optical activity covering the whole range of possible values. To interpret the simulation results, we develop a chiral coupled-mode model which yields analytical expressions that fit accurately the numerical data in a broad wavelength range. Our conclusions undoubtedly link the extreme optical chirality to the plasmon resonances of chiral holes and the associated chiral Fano-type transmission resonance.

Prospects of using metal-hole arrays for the enhanced optical detection of molecular chirality in nanosized volumes are investigated. Light transmission through the holes filled with an optically active material is modeled, and the activity enhancement by more than an order of magnitude is demonstrated. The spatial resolution of the chirality detection is shown to be of a few tens of nanometers. From comparing the effect in arrays of cylindrical holes and holes of complex chiral shape, it is concluded that the detection sensitivity is determined by the plasmonic near-field enhancement. The intrinsic chirality of the arrays due to their shape appears to be less important.

The ambiguity of the macroscopic description of light pressure on a continuous medium originates from the uncertainty of dividing the energy-momentum tensor of electromagnetically excited matter into a material and field parts or, equivalently, the total acting force into pressure and deformation terms. We show that, although there exists a continuum of formally correct formulations, one can adopt the appropriate form of the macroscopic field stress tensor that allows a unified description of pressure during elementary light-matter interactions, such as reflection, refraction, absorption, and nonlinear conversion. The derived simple expressions for the pressure force are compatible with the polariton momentum $\hslash \mathbf{k}$. The corresponding relation for the electromagnetic momentum density generalizes Rytov's definition for right-handed and left-handed frequency dispersive media. DOI: http://dx.doi.org/10.1103/PhysRevA.88.011804 ©2013 American Physical Society

The fluctuation effects at the boundary between the internal solid and external liquid regions of the Earth’s core are considered within the vitrification model. If the internal core is characterized

We study optical properties of subwavelength arrays of 3D-chiral metal holes exhibiting extreme circular dichroism and optical activity. The nanoscale shape features resolved by atomic force microscopy were processed with the developed AFM-to-FDTD data pipeline for reconstruction, averaging and preparation of the hole shape for FDTD simulations. The simulation results point unambiguously at the chiral localized plasmon resonance as the cause of the extreme optical chirality.

The ambiguity of macroscopic description of light pressure on continuous medium originates from the uncertainty of dividing the energy-momentum tensor of electromagnetically excited matter into material and field parts or, equivalently, the total acting force into pressure and deformation terms. We show that from the continuum of formally correct formulations, one can adopt the appropriate form of the macroscopic field stress tensor that allows unified description of pressure during elementary light-matter interactions in right-handed and left-handed frequency dispersive media. The proposed expressions for the pressure force are simple, convenient and compatible with the polariton momentum fik. The corresponding electromagnetic momentum density generalizes Rytov's definition.