Unidirectional Amplification and Shaping of Optical Pulses by Three-Wave Mixing with Negative Phonons

A possibility to greatly enhance frequency-conversion efficiency of stimulated Raman scattering is shown by making use of extraordinary properties of three-wave mixing of ordinary and backward waves. Such processes are commonly attributed to negative-index plasmonic metamaterials. This work demonstrates the possibility to replace such metamaterials that are very challenging to engineer by readily available crystals which support elastic waves with contra-directed phase and group velocities. The main goal of this work is to investigate specific properties of indicated nonlinear optical process in short pulse regime and to show that it enables elimination of fundamental detrimental effect of fast damping of optical phonons on the process concerned. Among the applications is the possibility of creation of a family of unique photonic devices such as unidirectional Raman amplifiers and femtosecond pulse shapers with greatly improved operational properties.Comment: 6 pages, 4 figures. arXiv admin note: text overlap with arXiv:1304.681

Property control methods of diamond-like silicon-carbon films for micro- and nanoelectronics

Possible methods for controlling the properties of amorphous diamond-like silicon-carbon films are considered: physical or structural modification, chemical modification, and physical-chemical modification. It is shown that the method of physical modification allows controlling in a wide range the properties of diamondlike silicon-carbon films (electrophysical, mechanical properties and surface morphology) without changing the chemical composition of the material. Chemical modification was carried out by introducing transition metal into diamond-like silicon-carbon films. The dependences of the phase composition, electrophysical and mechanical properties on the content and type of metal are analyzed. The method of physical-chemical modification is considered, when the introduced impurity changes not only the chemical composition, but also the structure of the material

All-optically transformable broad-band transparency and amplification in negative-index films

The possibility to produce laser-induced optical transparency of the metamaterial slab through the entire negative-index frequency domain is shown above the certain intensity threshold of the control laser field.Comment: 3 pages, 3 figures, 1 tabl

Data visualization tools for materials properties research

In work presented the results of research the algorithms of experimental data visualization, which obtain in the simulation of materials. The algorithms study was carried out on the example of the complete cycle for calculating the properties of an ideal diamond crystal. The calculation of crystal lattice properties was carried out using a software package for materials simulation. The obtained experimental data were analyzed using program REM_Viewer in which have been realized the algorithms of data visualization

Numerical research of materials crystal lattice parameters based on rare-earth metals

Geometrical parameters (coordinates and angles) of CeO2 crystal lattice by molecular dynamics method are calculated. Calculated parameters of crystal lattice are applied for definition the energy band structure via Hartree-Fock method in an approximation to CO LCAO (crystal orbitals as linear combination of atomic orbitals) and using the model of cyclic cluster. Calculated minimum energy band p-d is within the value range of experimental data. Valence band maximum is 4.2 while minimum energy band p-d width is 2.8 eV Quantum-chemical calculations are accelerated by Schwarz inequality and direct inversion method in iterative subspace. The obtained mathematical model is implemented into software package for calculating material properties

New Perturbation Theory for Nonstationary Anharmonic Oscillator

The new perturbation theory for the problem of nonstationary anharmonic oscillator with polynomial nonstationary perturbation is proposed. As a zero order approximation the exact wave function of harmonic oscillator with variable frequency in external field is used. Based on some intrinsic properties of unperturbed wave function the variational-iterational method is proposed, that make it possible to correct both the amplitude and the phase of wave function. As an application the first order correction are proposed both for wave function and S-matrix elements for asymmetric perturbation potential of type $V(x,\tau)=\alpha (\tau)x^3+\beta (\tau)x^4.$ The transition amplitude ''ground state - ground state'' $W_{00}(\lambda ;\rho)$ is analyzed in detail depending on perturbation parameter $\lambda$ (including strong coupling region $$ $\sim 1$) and one-dimensional refraction coefficient $\rho$.Comment: LaTeX, 13 page

Some Aspects of the Chemistry of Samarium (II) Compounds

Although the normal oxidation state of the rare earth elements is the tripositive one, several of them are capable of exhibiting either a lower or a higher valence of variable degrees of stability. Of particular interest in this investigation was the divalent state exhibited by samarium. It is well known that half-filled electronic shells tend to be rather stable. Divalent europium with electronic configuration of Xe 4f7* forms quite stable compounds which are slowly oxidized by water. Another stable rare earth divalent ion is Yb++ where the 4f shell is complete, (Xe 4f14), divalent samarium ion, on the other hand, only approaches a half filled shell (Xe 4f6 ) and is consequently extremely susceptible to oxidation. The first known samarium (II) compound was the chloride prepared by Matignon in 1906 (1). Later investigators prepared the bromide (2) and the iodide (3). All of these compounds were obtained by hydrogen or ammonia reduction of the corresponding trivalent halides at elevated temperatures. The iodide can likewise be prepared by the thermal decomposition of the SmI3 (3). Several of the divalent samarium compounds have been prepared by metathetical reactions in aqueous solutions; the sulfate, the chromate and the phosphate by Jantsch and Skalla (3) and the fluoride, the citrate and the carbonate by Clifford and Beachell (4). Of all these compounds only the sulfate could be isolated and analyzed. Several investigators have reported a green colored samarium (II) compound (4, 5) which was, presumably, either a carbonate or a hydroxide. The unusual color is rather interesting since all other compounds of divalent samarium are red