Vladimir Ostatochnikov

Influence of size effects on the optical characteristics of a one-dimensional photonic crystal with a nanocomposite defect

The spectral characteristics of a one-dimensional photonic crystal with an inset made of a heterogeneous composite material containing metal nanoparticles of different sizes have been studied. The influence of the size-dependent relative permittivity of nanoparticles on the spectrum of the photonic crystal has been demonstrated.

Defect mode suppression in a photonic crystal with a magnetic defect in the ferromagnetic resonance region

The specific features of the transmission and reflection spectra of a one-dimensional photonic crystal structure with a magnetically active layer placed between dielectric Bragg mirrors have been investigated. If the magnetic resonance frequency coincides with the frequency of the defect mode in one of the photonic bands, the defect mode in the photonic crystal can be completely suppressed, which makes it possible to effectively control the spectrum of such a structure by an external magnetic field.

Effective defect mode suppression in a magnetophotonic crystals in the magnetic resonance region

The influence of magnetic field on the reflection spectra of one-dimensional magneto-photonic crystals of two types has been investigated. The first type is a periodically layered defect-free magnetic-dielectric structure, the second one is a magnetically active defect placed between dielectric photonic crystal mirrors. If the frequency of magnetic resonance is close to the central frequency of one of the photonic band gaps or to the frequency of the defect mode, it creates a significant reconstruction of the spectrum in the mentioned frequency domain. Namely, it can bring the suppression of the oscillation spectrum and the defect mode, which makes it possible to effectively control the spectrum of such a structure by an external magnetic field.

Resonance splitting effect in one-dimensional photonic crystal with nanocomposite layer

The optical spectra of the photonic crystal structure is shown to be controlled by changing the structural parameters of plasmonic nanocomposite layer. Variation in particle size and volume fraction has an effect on the number and magnitude of defect modes in the optical spectra. The defect-mode splitting is found to be determined by dispersive properties of nanocomposite layer and PC mirrors.

Microwave generator based on tunnel-coupled semiconductor-metamaterial structure

We propose a model of a tunable laser based on a tunnel-coupled waveguide semiconductormetamaterial structure. The waveguide semiconductor channel has a positive refractive index and a high Kerr nonlinearity coefficient. In the frequency range under investigation, the channel formed by the magnetoactive metamaterial is characterized by a negative refractive index. Computer simulation is used for investigating the peculiarities of generation of microwave radiation under pumping due to modulated instability in the semiconductor channel and a distributed feedback. The generation frequency is controlled using the dependence of the refractive index of the metamaterial on the external magnetic field.

The effect of picosecond laser pulses on redox-dependent processes in mice red blood cells studied in vivo

The study highlights the effect of different modes of in vivo laser irradiation of mice using a PFL8LA laser with λ = 1560 nm, pulse duration of 1,4•10-12 s, peak power of 3,72•103 W and average output power of 20•10-3 W on the lipid peroxidation parameters: conjugated dienes, ketodienes and conjugated trienes, malondialdehyde, Schiff bases and the activity of antioxidant enzymes - catalase, glutathione -S-transferase and superoxide dismutase in erythrocytes and plasma of mice. Two groups of mice received a total dose of 3.8 J/cm2 per group, but the 1st group was irradiated only once, while the 2nd – four times. Significant differences in the parameters of the 1st and 2nd groups indicate different effects of the irradiation modes on redox-dependent processes in red blood cells of mice.

Transmission and reflection spectra of photonic crystal with plasmonic defect layer

The possibility of using plasmonic nanocomposite with nonspherical metal inclusions as a tuning defect in a photonic crystal is considered. Polarization-dependent features appearing when the electromagnetic wave is reflected from and transmitted through a photonic crystal with plasmonic defect are studied.

Effects of femtosecond laser radiation on blood cell suspensions

In the present work the effects of high-power femtosecond laser irradiation on a functional condition of red blood cells and neutrophils in vitro have been investigated. The data on parameters of the lipid peroxidation - antioxidants system, hemoglobin level and rigidity of red blood cell membranes testify destabilization of the membranes under the influence of the given laser. The study of phagocytic activity, anaerobic and aerobic metabolism of neutrophils, and rigidity of their membranes allows to suppose the dose-dependent effect to be stimulating.