Optics and spectroscopy. Laser physics

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.

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).

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.

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).

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.

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.

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.

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.

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.

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.

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