title: Implications of the causality principle for ultra chiral metamaterials.
abstract: Chiral metamaterials - artificial subwavelength structures with broken mirror symmetry - demonstrate outstanding degree of optical chirality that exhibits sophisticated spectral behavior and can eventually reach extreme values. Based on the fundamental causality principle we show how one can unambiguously relate the metamaterial circular dichroism and optical activity by the generalized Kramers-Kronig relations. Contrary to the conventional relations, the generalized ones provide a unique opportunity of extracting information on material-dependent zeroes of transmission coefficient in the upper half plane of complex frequency. We illustrate the merit of the formulated relations by applying them to the observed ultra chiral optical transmission spectra of subwavelength arrays of chiral holes in silver films. Apart from the possibility of precise verification of experimental data, the relations enable resolving complex eigenfrequencies of metamaterial intrinsic modes and resonances.
authors: A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333 Moscow, Russia.
authors: Maxim V
authors: MV
authors: Gorkunov
authors: A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333 Moscow, Russia.
authors: Vladimir E
authors: VE
authors: Dmitrienko
authors: 1] A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333 Moscow, Russia [2] M. V. Lomonosov Moscow State University, 119991 Moscow, Russia [3] A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Science, 119991 Moscow, Russia.
authors: Alexander A
authors: AA
authors: Ezhov
authors: A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333 Moscow, Russia.
authors: Vladimir V
authors: VV
authors: Artemov
authors: A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 119333 Moscow, Russia.
authors: Oleg Y
authors: OY
authors: Rogov