Sergey L. Prosvirnin

Sharp Trapped-Mode Resonances in Planar Metamaterials with a Broken Structural Symmetry

We report that a resonance response with a very high quality factor can be achieved in a planar metamaterial by introducing symmetry breaking in the shape of its structural elements, which enables excitation of trapped modes, i.e., modes that are weakly coupled to free space.

Metamaterial Analog of Electromagnetically Induced Transparency

We demonstrate a classical analog of electromagnetically induced transparency in a planar metamaterial. We show that pulses propagating through such metamaterials experience considerable delay. The thickness of the structure along the direction of wave propagation is much smaller than the wavelength, which allows successive stacking of multiple metamaterial slabs leading to increased transmission and bandwidth.

Asymmetric propagation of electromagnetic waves through a planar chiral structure

We report the first experiential observation and theoretical analysis of the new phenomenon of planar chiral circular conversion dichroism, which in some aspects resembles the Faraday effect in magnetized media, but does not require the presence of a magnetic field for its observation. It results from the interaction of an electromagnetic wave with a planar chiral structure patterned on the sub-wavelength scale, and manifests itself in asymmetric transmission of circularly polarized waves in the opposite directions through the structure and elliptically polarized eigenstates. The new effect is radically different from conventional gyrotropy of three-dimensional chiral media.

Metamaterial with polarization and direction insensitive resonant transmission response mimicking electromagnetically induced transparency

We report on a planar metamaterial, the resonant transmission frequency of which does not depend on the polarization and angle of incidence of electromagnetic waves. The resonance results from the excitation of high-Q antisymmetric trapped current mode and shows sharp phase dispersion characteristic to Fano-type resonances of the electromagnetically induced transparency phenomenon.

Nanostructured Metal Film with Asymmetric Optical Transmission

We demonstrate for the first time a nanostructured planar photonic metamaterial transmitting light differently in forward and backward directions.

Mirror that does not change the phase of reflected waves

We report that electromagnetic wave reflected from a flat metallic mirror superimposed with a planar wavy metallic structure with subwavelength features that resemble “fish scales” reflects like a conventional mirror without diffraction, but shows no phase change with respect to the incident wave. Such unusual behavior resembles a reflection from a hypothetical zero refractive index material, or “magnetic wall”. We also discovered that the structure acts as a local field concentrator and a resonant “amplifier” of losses in the underlying dielectric.

Resonances of Closed Modes in Thin Arrays of Complex Particles

Numerical analysis of the reflection properties of double-periodic thin arrays is carried out. This analysis indicates the presence of extremely high quality band stop and band pass resonances due to the excitation of non-symmetric current mode.

Optical bistability involving planar metamaterials with broken structural symmetry

We report on a bistable light transmission through a planar metamaterial consisted of a metal pattern of weakly asymmetric elements placed on a nonlinear substrate which enables sharp resonance response by excitation of a trapped mode. A feedback required for bistability is provided by the coupling between strong trapped mode resonance antiphased currents exited on the metal elements and an intensity of inner field in the nonlinear substrate.

Polarization transformations by a magneto-photonic layered structure in the vicinity of a ferromagnetic resonance

Polarization properties of a magneto-photonic layered structure are studied at frequencies close to the frequency of ferromagnetic resonance. The investigations are carried out taking into account a large value of dissipative losses in biased ferrite layers in this frequency band. The method is based on analysis of solution stability of an ordinary differential equation system regarding the field inside a periodic stack of dielectric and ferrite layers. The electromagnetic properties of the structure are ascertained by analysis of the eigenvalues of the transfer matrix of the structure period. The frequency boundaries of the stopbands and passbands of the eigenwaves are determined. The frequency and angular dependences of the reflection and transmission coefficients of the stack are presented. Frequency dependences of a polarization rotation angle and ellipticity of the reflected and transmitted fields are analyzed. An enhancement of polarization rotation due to the periodic stack is mentioned, in comparison with the rotation due to some effective ferrite slab.

Analysis of polarization transformations by a planar chiral array of complex-shaped particles

Vectorial relations of field amplitudes are derived from the Lorentz lemma applied to electromagnetic fields at direct and reversed scenarios of a wave diffraction on a doubly-periodic planar array. Biorthogonality of polarization eigenstates of the waves propagating in opposite directions is shown with reference to a wave channel formed by an incident wave and a diffraction order. For a planar chiral array, an essential difference in polarization transformations of propagated waves is ascertained in the direct wave channel and in the reversed one. Numerical data are presented to demonstrate the polarization transformations by both transmitting and reflecting planar chiral arrays. A difference in polarization eigenstates inherent to a planar chiral array and a bulk chiral medium is noticed.