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

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

Dynamic optical bistability in resonantly enhanced Raman generation

We report observations of novel dynamic behavior in resonantly-enhanced stimulated Raman scattering in Rb vapor. In particular, we demonstrate a dynamic hysteresis of the Raman scattered optical field in response to changes of the drive laser field intensity and/or frequency. This effect may be described as a dynamic form of optical bistability resulting from the formation and decay of atomic coherence. We have applied this phenomenon to the realization of an all-optical switch.Comment: 4 pages, 5 figure

Some Thoughts on Linguistic and Cultural Peculiarities of Cross Cultural Online communication

The author concludes that while communicating online one should take into consideration cultural differences of the communicants as well as mutual interference of language and culture which determines cultural and linguistic peculiarities of Internet texts

Diffusion-induced Ramsey narrowing

A novel form of Ramsey narrowing is identified and characterized. For long-lived coherent atomic states coupled by laser fields, the diffusion of atoms in-and-out of the laser beam induces a spectral narrowing of the atomic resonance lineshape. Illustrative experiments and an intuitive analytical model are presented for this diffusion-induced Ramsey narrowing, which occurs commonly in optically-interrogated systems.Comment: 4 pages, 8 figure

Century-long Dynamics of Meadow Steppes in the Privolzhskaya Uplands

Information on the structure and dynamics of the zonal Central Russian meadow steppes is presented in terms of the example of the Privolzhskaya forest-steppe state nature reserve (Penza region, Russia). The cenotic diversity of the herbaceous vegetation of the reserve is represented by 91 associations, of which 48 referto steppes and 43 to steppe meadows. It has been revealed that the vegetation of the studied placer sites under the influence of an absolutely reserved regime undergoes mesophyticization and silvatization, which are more intensively manifested in the forest-steppe landscapes of the secondary moraine plains (areas of thePoperechenskaya steppe and Ostrovtsovskaya forest-steppe reserve) than in the eroded denudational plains of forest-steppe landscapes (areas of the Kuncherovskaya steppe and Ostrovtsovskaya forest-steppe reserves). The study of the dynamics of zonal meadow steppes in the Volga Uplands testifies to the inevitability of theirtransformation in modern climatic conditions into meadow, shrubby and even forest communities. Keywords: forest-steppe, meadow steppes, structure, dynamics, succession, reserve, geobotanical mapping, protection of steppe vegetatio

Coherent population trapping resonances with linearly polarized light for all-optical miniature atomic clocks

We present a joint theoretical and experimental characterization of the coherent population trapping (CPT) resonance excited on the D1 line of 87Rb atoms by bichromatic linearly polarized laser light. We observe high-contrast transmission resonances (up to 25%), which makes this excitation scheme promising for miniature all-optical atomic clock applications. We also demonstrate cancellation of the first-order light shift by proper choice of the frequencies and relative intensities of the two laser field components. Our theoretical predictions are in good agreement with the experimental results.Comment: 8 pages, 7 figure

Coherent-population-trapping resonances with linearly polarized light for all-optical miniature atomic clocks

We present a joint theoretical and experimental characterization of the coherent population trapping (CPT) resonance excited on the D(1) line of (87)Rb atoms by bichromatic linearly polarized laser light. We observe high-contrast transmission resonances (up to approximate to 25%), which makes this excitation scheme promising forminiature all-optical atomic clock applications. We also demonstrate cancellation of the first-order light shift by proper choice of the frequencies and relative intensities of the two laser-field components. Our theoretical predictions are in good agreement with the experimental results

EIT and diffusion of atomic coherence

We study experimentally the effect of diffusion of Rb atoms on Electromagnetically Induced Transparency (EIT) in a buffer gas vapor cell. In particular, we find that diffusion of atomic coherence in-and-out of the laser beam plays a crucial role in determining the EIT resonance lineshape and the stored light lifetime.Comment: 5 pages, 8 figure