Theory of radiation trapping by the accelerating solitons in optical fibers

We present a theory describing trapping of the normally dispersive radiation by the Raman solitons in optical fibers. Frequency of the radiation component is continuously blue shifting, while the soliton is red shifting. Underlying physics of the trapping effect is in the existence of the inertial gravity-like force acting on light in the accelerating frame of reference. We present analytical calculations of the rate of the opposing frequency shifts of the soliton and trapped radiation and find it to be greater than the rate of the red shift of the bare Raman soliton. Our findings are essential for understanding of the continuous shift of the high frequency edge of the supercontinuum spectra generated in photonic crystal fibers towards higher frequencies.Comment: Several misprints in text and formulas corrected. 10 pages, 9 figures, submitted to Phys. Rev.

Looking at a soliton through the prism of optical supercontinuum

A traditional view on solitons in optical fibers as robust particle-like structures suited for informa- tion transmission has been significantly altered and broadened over the past decade, when solitons have been found to play the major role in generation of octave broad supercontinuum spectra in photonic-crystal and other types of optical fibers. This remarkable spectral broadening is achieved through complex processes of dispersive radiation being scattered from, emitted and transformed by solitons. Thus solitons have emerged as the major players in nonlinear frequency conversion in optical fibers. Unexpected analogies of these processes have been found with dynamics of ultracold atoms and ocean waves. This colloquium focuses on recent understanding and new insights into physics of soliton-radiation interaction and supercontinuum generation.Comment: http://rmp.aps.org/abstract/RMP/v82/i2/p1287_1 (some figures have been deleted due to space limits imposed by archive

Energy Flow Puzzle of Soliton Ratchets

We study the mechanism of directed energy transport for soliton ratchets. The energy flow appears due to the progressive motion of a soliton (kink) which is an energy carrier. However, the energy current formed by internal system deformations (the total field momentum) is zero. We solve the underlying puzzle by showing that the energy flow is realized via an {\it inhomogeneous} energy exchange between the system and the external ac driving. Internal kink modes are unambiguously shown to be crucial for that transport process to take place. We also discuss effects of spatial discretization and combination of ac and dc external drivings.Comment: 4 pages, 3 figures, submitted to PR

Compositional trends of amphibole in 2001-2003 Young Shiveluch andesites as evidence of magma chamber replenishment and subsequent convection

Hornblende-plagioclase andesites of the Young Shiveluch volcano erupted from 2001 to 2013 show minor variations of whole rock and matrix glass compositions but large variations of mineral phenocryst compositions. We focused this work on the composition of amphiboles in andesites from the growing Shiveluch lava dome, pumiсeous rocks from pyroclastic flows and rare mafic inclusions. We propose that the shallow magma chamber was replenished during this time that enhances magma convection and caused more frequent eruptions..

Formation of self-organized organic-inorganic hybrids

The morphology features and peculiarities of current-voltage characteristics of selforganized organic–silicon hybrids were investigated. The organic layers were formed by chemical bath deposition at room temperatures of phosphorus doped n-type FZ Si-patterned substrate. The pattern was formed by etching in anisotropic etch on the base of aqueous solution of potassium hydrate KOH and isopropyl alcohol. The following aqueous solutions of organic heterocyclic aromatic compounds were used for hybrids formation: sulfacyl sodium, procainamide hydrochloride (novocain) and lamotridgine. These hybrids have shown different types of morphology. This depends on substrate properties, time deposition and organic concentration in water solution. The photovoltaic effect of organic-pattern silicon is the result of chemisorptions of functional amine, amide, carboxyl, thiols and halogen groups on silicon pattern-type surface. At the same time these results have proven that the substrate of start and classic morphology in pyramid form is favored for formation of organic-silicon hybrids for photovoltaic application.Досліджено морфологічні властивості та особливості характеристик струм–напруга для самоорганізованих кремнійорганічних гібридів. Органічні шари було одержано хімічним осадженням за кімнатної температури легованих фосфором візерункових кремнієвих субстратів FZ n-типу. Візерунок формували витравлюванням в анізотропних травниках на основі водного розчину гідрату калію КОН та ізопропилового спирту. В подальшому для отримання гібридів використовували водні розчини органічних гетероциклічних сполук: сульфосаліцилового натрію, гідро хлориду прокаінаміду (новокаїну) і ламотріджину. Ці гібриди показали різну морфологію. Вона залежить від властивостей субстрату, часу осадження та концентрації органічної складової у водних розчинах. Фотогальванічний ефект кремнійорганічного рисунка є результатом хемосорбції функціональних груп амінів, амідів, карбоксилу, тріолів та галогену на поверхні кремнію. Водночас, ці результати підтверджують,що субстрат початкової і класичної морфології у вигляді піраміди кращий для утворення кремнійорганічних гібридів фотогальванічного застосування.Исследованы морфологические свойства и особенности характеристик ток–напряжение для самоорганизующихся кремнийорганических гибридов. Органические слои были получены химическим осаждением при комнатной температуре легированных фосфором узорчатых кремниевых субстратов FZ n-типа. Узор формировали вытравливанием в анизотропных травителях на основе водного раствора гидрата калия KOH и изопропилового спирта. В дальнейшем для получения гибридов использовали водные растворы органических гетероциклических соединений: сульфосалицилового натрия, гидрохлорида прокаинамида (новокаина) и ламотритриджина. Эти гибриды показали различную морфологию. Она зависит от свойств субстрата, времени осаждения и концентрации органической составляющей в водных растворах. Фотогальванический эффект кремнийорганического рисунка является результатом хемосорбции функциональных групп аминов, амидов, карбоксила, триолов и галогена на поверхности кремния. В то же самое время, эти результаты подтверждают, что субстрат начальной и классической морфологии в виде пирамиды является предпочтительным для образования кремнийорганических гибридов фотогальванического применения

Peculiarities of bone regenerate formation, structural changes in joint cartridge and tibial nerve in the conditions of 3-mm automatic distraction of the tibia with the Ilizarov method and application of achillotomy (experimental study)

Introduction Reduction of the period of limb lengthening with the Ilizarov method and preservation of limb functions in large elongations are the tasks to be solved by modern traumatology and orthopedics. The aim was to study the functional state of the limb, dynamics of the tibial regenerate formation, histostructural changes in the articular cartilage and the tibial nerve under the conditions of automatic high-frequency elongation of the tibia with the method of transosseous distraction osteosynthesis at a rate of 3 mm using a preliminary Z-shaped achillotomy. Material and methods The 24-hour high-fractional mode provided with automatic distractor was used to lengthen tibiae of 12 adult mongrel dogs with the method of transosseous distraction osteosynthesis. Distraction rate was 3.0 mm per day in 120 steps. To prevent formation of foot equinus, a Z-shaped achillotomy was performed. Methods of light microscopy, morphometry and X-ray electron probe microanalysis were used to study the distraction regeneration in the tibia, the articular cartilage of the medial condyle of the femur and the tibial nerve. Results During the periods of distraction and fixation, the regenerate was characterized by a normotrophic structure with a large proportion of bone component which provided the limb support function after 45 days of the experiment. Thirty days after the removal of the apparatus, a newly formed bone of a typical structure was seen in the distraction gap. Achillotomy helped prevent equinus deformity of the foot and flexion contractures of the knee joint and the metatarsal joint. However, histostructural changes in the articular cartilage were detected at the stages of osteosynthesis. Despite the restoration of the thickness of the cartilage, there was a decrease in the number of isogenic groups and the presence of cells with chondoptosis by the end of the experiment. Not a single case of neuropathy of the tibial nerve was revealed histologically due to prevention of overstretching of the anterior surface of the tibia by an increase in the length of the calcaneal tendon with tenotomy. The proportion of destructively altered nerve fibers in all animals did not exceed 5 %. Necrobiotic changes in the epineural vessels were compensated by hypervascularization of the epineurium and endonevria, as a result of which the majority of nerve conductors retained their normal structure, numeric density, and restored dimensional characteristics at the end of the experiment. Conclusions The conditions of the experiment provide for functional restoration of the limb, promote active reparative osteogenesis and structural adaptation of the tibial nerve, do not cause any gross destructive changes in the articular cartilage and reduce the period with the Ilizarov frame on by 30 % as compared with the classical variant

Vortex solitons in an off-resonant Raman medium

We investigate existence and linear stability of coupled vortex solitons supported by cascaded four-wave mixing in a Raman active medium excited away from the resonance. We present a detailed analysis for the two- and three-component vortex solitons and demonstrate the formation of stable and unstable vortex solitons, and associated spatio-temporal helical beams, under the conditions of the simultaneous frequency and vortex comb generation.Comment: 8 pages, 10 figures, to be published in Phys. Rev.