Enhancement of Kerr nonlinearity via multi-photon coherence

We propose a new method of resonant enhancement of optical Kerr nonlinearity using multi-level atomic coherence. The enhancement is accompanied by suppression of the other linear and nonlinear susceptibility terms of the medium. We show that the effect results in a modification of the nonlinear Faraday rotation of light propagating in an Rb87 vapor cell by changing the ellipticity of the light.Comment: 4 pages, 3 figures Submitted to Optics Letter

Observation of polarization quantum noise of laser radiation in Rb vapor cell

We present experimental study of polarization quantum noise of laser radiation passed through optically think vapor of Rb87. We observe a step-like noise spectrum. We discuss various factor which may result in such noise spectrum and prevent observation of squeezing of quantum fluctuations predicted in Matsko et al. PRA 63, 043814 (2001).Comment: 4 pages, 5 figures. Translated from Russian by I. Novikov

Radiation trapping in coherent media

We show that the effective decay rate of Zeeman coherence, generated in a Rb87 vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced transparency experiments with optically thick media

Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas

We experimentally study the group time delay for a light pulse propagating through hot Rb vapor in the presence of a strong coupling field in a $\Lambda$ configuration. We demonstrate that the ultra-slow pulse propagation is transformed into superluminal propagation as the one-photon detuning of the light increases due to the change in the transmission resonance lineshape. Negative group velocity as low as -c/10^6=-80 m/s is recorded. We also find that the advance time in the regime of the superluminal propagation grows linearly with increasing laser field power.Comment: 5 pages, 6 figure

Local development initiatives as promoters of social innovation: evidence from two European rural regions

Social innovation entered the academic discourse several decades ago and has since been seen as a way of tackling existing problems in various contexts. Although an extensive body of research has been conducted into the role of social innovation in urban context, there is still a gap when it comes to studying the role of social innovation in the development of rural areas. In this paper, an attempt is made to look at the role of Local Action Groups (LAGs) and Local Development Associations (LDAs) as promoters of social innovation in rural areas in Austria and Portugal, aiming to understand the role of such organisations and the challenges faced by the latter in promoting social innovation.info:eu-repo/semantics/publishedVersio

ЄВРОПЕЙСЬКА МОДЕЛЬ КРЕДИТУВАННЯ СУБ’ЄКТІВ МАЛОГО БІЗНЕСУ

In the article investigated the experience of formation, development and operation of small business crediting in the developed countries. Also systematic differences between foreign experience of small businesses crediting based on the determination of the European model of crediting.Studying the experience of a European model of lending to small businesses is important in terms of developing a long-term strategy for developing and supporting small businesses. Much of this experience can be reflected in the legal, organizational and institutional forming of Ukrainian policy related to small business, both at the national level and at the level of each individual region. According to the realities of the Ukrainian economy of these foreign tools that promote small business loans, you can create associations of mutual guarantees and state insurance fund credit risks. Using these tools will allow small businesses receive guarantees from its counterparties to obtain credit in the bank, not to burden the state budget and develop financial risk insurance.В статье проведено исследование опыта становления, развития и функционирования кредитования малого бизнеса в развитых странах. Также систематизированы отличия иностранного опыта кредитования малого бизнеса на основе определения содержания европейской модели кредитования.В статті досліджено досвід розвинутих країн щодо становлення, розвитку та функціонування кредитування малого бізнесу. Також, систематизовано відмінності зарубіжного досвіду кредитування малого бізнесу на основі визначення змістовності європейської моделі кредитування