Browsing by Author "Vetrov, Stepan Ya"

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Chiral Optical Tamm States at the Interface between an All-Dielectric Polarization-Preserving Anisotropic Mirror and a Cholesteric Liquid Crystal
(2019-10-01)
Rudakova, Natalya, V
;
Timofeev, Ivan, V
;
Bikbaev, Rashid
;
Pyatnov, Maxim, V
;
Vetrov, Stepan Ya
As a new localized state of light, the chiral optical Tamm state exists at the interface between a polarization-retaining anisotropic mirror and a substance with optical activity. Considering a hybrid structure comprising a metal-free polarization-preserving mirror and a cholesteric liquid crystal, we highlight the high Q factor arising from the all-dielectric framework. The intensity of localized light decreases exponentially with increasing distance from the interface. The penetration of the field into the cholesteric liquid crystal is essentially prohibited for wavelengths lying in the photonic bandgap and close to the cholesteric pitch length. The dielectric mirror has its own photonic bandgap. The energy transfer along the interface can be effectively switched off by setting the tangential wave vector to zero. The spectral behavior of the chiral optical Tamm state is observed both as reflection and transmission resonance. This Fano resonance is analogous to the Kopp-Genack effect. Our analytics are well in line with precise calculations, which may pave a new route for the future development of intelligent design for laser and sensing applications.
Enhanced light absorption with a cholesteric liquid crystal layer
(2013-04-01)
Timofeev, Ivan V.
;
Arkhipkin, Vasily G.
;
Vetrov, Stepan Ya
;
Zyryanov, Victor Ya
;
Lee, Wei
We discuss the trapping features of cholesteric liquid crystal as a self-organized photonic crystal and suggest it for absorption improvement. The imperfection of the absorbing surface is manifested by the reflection originating from the indispensable impedance mismatch. The reflection can be suppressed by an additional surface coating to reflect the light back to the absorber once again. In the simple consideration this reflection loop is possible only twice. For a right-handed CLC coating, the boundary reflection switches the light polarization from left to right circular in the first loop and it switches in the second loop back to the left circular polarization before the emerging light finally escapes from the absorbing process. The enhancement of light absorption is possible in the frequency range as large as the photonic bang gap of the cholesteric layer, which can be adjusted as desired. (C) 2013 Optical Society of America
Optical Tamm states at the interface between a photonic crystal and an epsilon-near-zero nanocomposite
(2017-08-01)
Vetrov, Stepan Ya
;
Bikbaev, Rashid G.
;
Rudakova, Natalya V.
;
Chen, Kuo-Ping
;
Timofeev, Ivan V.
The spectral properties of a one-dimensional photonic crystal bounded with a resonance-absorbing nanocomposite layer are investigated. The bulk concentrations of metal nanoparticles dispersed in a transparent nanocomposite matrix are determined at which the effective permittivity takes near-zero values. The transmission, reflection and absorption spectra of the investigated structures at the normal incidence of light are calculated. The demonstrated possibility of formation of the optical Tamm states at the interface between the photonic crystal and nanocomposite is ensured by the near-zero real and imaginary parts of the permittivity or only the imaginary part of the permittivity at the zero real part. The specific features of field localization at the optical Tamm state frequencies are examined.