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Dynamic Light Scattering Method in Studies of Silica and Gold Nanoparticles

Authors: Khlebtsov B. N., Khanadeev V. А., Pylaev T. Е., Khlebtsov N. G.

Background and Objectives: It is well known, that uncritical use of the dynamic light scattering (DLS) method may give unacceptable results for the volume or number distributions of particles as compared with transmission electron microscopy (TEM) data. The purpose of this study is to investigate application of the DLS method for determining the size of colloidal silica and gold nanoparticles and to compare results of three methods: DLS, TEM, and absorption spectroscopy (see next paper).

Application of Dynamic Light Scattering and Absorption Spectroscopy to Studies of Systems with Colloidal Gold Nanoparticles + DNA

Authors: Khlebtsov B. N., Pylaev T. Е., Khanadeev V. А., Khlebtsov N. G.

Background and Objectives: The dynamic light scattering (DLS) method is widely used to evaluate the particle size distributions. However, DLS is not free of serious drawbacks. For a fast approximate estimation of the average size of colloidal gold nanoparticles (AuNPs) within the range of 15–100 nm reasonable results can be obtained with using the absorption spectroscopy. We discuss the advantages and drawbacks of DLS, transmission electron microscope (TEM), and absorption spectroscopy in gold nanoparticle sizing.

Mathematical Modeling of Lihgt Transfer in Low-Coherence Reflectometry of Random Media

Authors: Zimnyakov D. A., Alonova M. V., Yuvchenko S. А., Ushakova E. V.

Background and Objectives: The mathematical model of stochastic interference of spectrally selected fluorescence radiation in multiple scattering random media is considered. The expressions for the normalized second- and third-order moments of spatial intensity fluctuations of detected probe light are derived.

Discrete-Eigenvalue Multiplexing for Soliton Fiber-Optic Communication Links

Authors: Konyukhov A. I., Mavrin P. А., Shchurkin E. V.

Background and Objectives: The nonlinear Fourier transform gives a powerful tool to analyze fiber-optics solitons. The solitons are described by a discrete set of eigenvalues of two coupled differential equations, which gives the nonlinear Fourier transform. Using the discrete eigenvalues for optical signal coding can increase the signal-to-noise ratio and reduce the effect of fiber nonlinearity. In the present paper an all-fiber-optics method is proposed to modulate the discrete eigenvalues.

Optical Absorption and Raman Scattering in Doped Crystals TlGaSe2 and TlInS2

Authors: Kaabi S. A., Drozdov N. А., Korolek О. V.

Background and Objectives. The TlGaSe2 and TlInS2 monocrystals are the А3В3С6 2 type ternary semiconductor compounds. Studies of TlGaSe2 and TlInS2 materials are carried out quite intensively due to the uniqueness of their optical and electrophysical properties and significant prospects for their practical use. At the same time, information about the effect of specific doping impurities on the properties of such materials is insufficient and often contradictory.

Intermolecular Interaction in Two-component Compounds of Nanodiamonds and Doxorubicin

Authors: Bokarev A. N., Plastun I. L.

Background and Objectives: Detonation nanodiamond (ND) is one of the most promising materials for targeted drug delivery – one of rapidly developing areas of modern chemistry, pharmacology and medicine. Wide possibilities of surface modification and advantageous dimensions make nanodiamonds very attractive objects for using in the drug delivery process. A number of studies have shown that therapeutic efficacy of drugs is enhanced and their toxicities may be attenuated with immobilization on the enriched ND. There are a lot of drug immobilization methods on ND surfacy.

Methods of Autodyne Interferometry of the Distance by Injected Current Modulation of a Semiconductor Laser

Authors: Usanov D. A., Skripal A. V., Dobdin S. Y., Astakhov E. I., Kostyuchenko I. S., Dzhafarov A. V.

Background and Objectives: Two methods of distance interferometry for two types of wave modulation of laser radiation have been presented. The methods of triangular and harmonic wave modulation of a signal have been described. The advantages of the triangular wave modulation method in combination with the use of the frequency of the self-mixing signal spectrum, as well as the advantages of the harmonic wave modulation method in combination with the use of the amplitudes of the self-mixing signal spectrum have been shown.

A Hybrid Approach in Modeling of Statistical Characteristics of Multiple Scattered Light

Authors: Alonova M. V., Ushakova O. V., Zimnyakov D. A., Baiburin V. B.

Background and Objectives: A hybrid approach to modeling of the statistical characteristics of multiple scattered light in application to optical probes of random media is considered. The approach is based on recovery of the probability density of path lengths for partial components of a scattered light field in a probed medium using approximate analytical methods or the numerical simulation.

Difference-Frequency Generator and Optical Parametric Oscillator Pumped by a Semiconductor Disk Laser: Comparative Study with a Time Delay Model

Authors: Morozov Y. A., Balakin M. I., Kochkurov L. A., Morozov M. Y.

Background and Objectives: High-resolution spectroscopy is known to need sources of coherent radiation in the mid- and farinfrared spectral bands. Sources based on optical nonlinear interaction (a difference-frequency generator and an optical parametric oscillator) are known to be almost ideally suitable for an application. Intracavity realizations of the devices with a nonlinear crystal located in the cavity, can likely be made simple, compact and easy to use.

Interpretation of IR and Raman Spectra of Albumin

Authors: Ten G. N., Gerasimenko A. Y., Shcherbakova N. Е., Baranov V. I.

Object and purpose of work: The subject of the study is bovine serum albumin (BSA). The aim of the work is to give an interpretation of the vibrational spectra of BSA aqueous solution in the region of ~1700–600 cm– 1. Methods: In this regard the experimental measurement of the IR and Raman spectra of BSA and the calculation of vibrational spectra of zwitterionic ion forms 20 amino acids and their dipeptides were carried out. The effect of anharmonicity and intermolecular interaction (IMI) on the vibrational spectra of amino acids was considered.

Optical Characteristics of Asymmetrical Hyperbolic Metamaterials

Authors: Kozina O. N., Melnikov L. A.

Background and Objectives: Metamaterials, which are artificial structures with specified properties, keep the interest to nest investigations and creation of new types of them due to their unusual properties. One of the promising variant of the metamaterials is hyperbolic metamaterials (HMM) which exhibit the hyperbolic-type dispersion in the space of wave-vectors and are described by the diagonal extremely anisotropic permittivity tensor.

The Influence of Hydrogen Bond on the Structure and IR Spectrum of Triphenyl Phosphite

Authors: Babkov L. M., Davydova N. A., Ivlieva-Peretokina I. V.

Background and Objectives: The IR spectra of triphenyl phosphite (TPP) have been measured at temperatures of 12 and 320 K in five phase states: crystalline (monoclinic and hexagonal phases), “glacial”, amorphous and liquid. It is necessary to clarify the effect of hydrogen bonding on the structure and IR spectrum of TPP. Materials and Methods: The IR spectra were measured on the IFS-88 spectrophotometer using the OPUS software. The spectral resolution was 2 cm^(-1).

Structural Features of Statistically Rotationally Invariant Mosaic Birefringent Layers That Show Circular Dichroism

Authors: Yakovlev D. D.

Background and Objectives: Nonabsorbing cholesteric liquid crystalline layers with a fine-domain random planar structure and with the cholesteric pitch being much larger than the wavelength of the incident light have been recently demonstrated to exhibit electricallyinduced circular dichroism due to scattering. Experimental conditions under which this effect was observed allow consideration of a problem of scattering of light on such a liquid-crystalline layer as a problem of diffraction of a light beam on a mosaic of chiral domains with different azimuthal orientation.

Referenceless Low-Coherence Reflectometry of Random Media under Wide-Band Spectral Selection of Scattered Probe Light

Authors: Isaeva E. A., Isaeva A. A., Zimnyakov D. A.

Background and Objectives: The optical probes of randomly inhomogeneous media, based on analysis of the statistical parameters of the scattered light intensity, are sensitive to optical, structural, and transport parameters of the medium. A promising approach among the low-coherence optical methods is an approach in which the medium is considered as a multi-beam interferometer with randomly distributed values of the path difference of the interfering beams (partial waves).

Method for Measuring Acceleration by the Spectrum of Self-Mixing Signal of Semiconductor Laser

Authors: Skripal A. V., Dobdin S. Y., Dzhafarov A. V., Sadchikova K. A., Dubrovskaia I. A.

Background and Objectives: Traditional methods for measuring the acceleration by changing the position of extremums on the time axis, as well as methods based on the use of least squares and wavelet analysis, require significant signal processing efforts: filtering and allocating extremums or significant time for processing an autodyne signal. The proposed method for measuring the acceleration of the spectrum of the self-mixing signal uses a well-established machine method of Fourier analysis, which is widely used for processing complex waveforms.

Influence of Sm Impurity Atoms on the Switching Effect in Thin Films of GeS

Authors: Madatov Selim oqly R. S., Alekperov A. S., Nabiyev A. E.

Background and Objectives: Nowadays interest has grown considerably to AivBvi type semiconductor media. Among them there is a special interest to the thin photosensitive films of germanium mono-sulfide. So, GeS thin layers have the ability to contain a large number of lithium ions. Therefore, it is possible to prepare the items: solar cells and super condenser. There are no limitations for practical applications of GeS crystal. Prospects of such semiconductor films are determined by the possibility of holographic recording and effects of switching and memory.

Phase Changes of Multiferroic Magnetic Materials, Used in External Memory Systems

Authors: Hlopov B. V., Chucheva G. V., Mityagina A. B.

Background and Objectives: A review of studies on technological bases of multiferroic materials for their possible use in devices for the urgent destruction of information is presented. The analysis of characteristics of materials allows one to specify their phase changes caused by external influences and to investigate the magnetic properties.

Electric and Magnetic-Field-Induced Formation of Macrostructures in Ferroelectric Liquid Crystals

Authors: Kudreyko A. A., Migranov N. G.

Background and Objectives: The study of ferroelectric liquid crystals in smectic C* phase fits together several most relevant research areas, including electro-optic devices with response time in the range of 10 μs. A distinguishing feature of smectic C* liquid crystals is its chiral layered structure, which is formed due to the center of masses orientational ordering along the preferred orientation [called the director].

Plasmon-polaritons Along the Asymmetric Hyperbolic Metamaterial

Authors: Davidovich M. V.

Background and Objectives: Plasmon-polaritons along a surface of bulk hyperbolic metamaterial and along a slab of such metamaterial with an arbitrary orientation of the crystallographic axis are considered (the axis in the polarization plane is an arbitrary angle with the direction of propagation). We use the rigorous approach based on Maxwell’s equations. The parameters of the hyperbolic metamaterial in the form of the effective dielectric constant tensor are determined by homogenization.

Study of Ethanol Impact on the Transepidermal Transport of Indocyanine Green with Backscattering Spectroscopy

Authors: Genina E. A., Bashkatov A. N., Tuchin V. V.

In the work, impact of aqueous 40%-ethanol solution on the transepidermal transport of photodynamic dye indocyanine green has been studied with backscattering spectroscopy. It has been first obtained the value of the dye diffusion coefficient through the stratum corneum ex vivo at the use of ethanol as a diffusion enhancer: (6.85±3.75)×10−7 cm2/s.

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