Enhancing capacity of coherent optical information storage and transfer in a Bose-Einstein condensate

Coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. Theory of slow light propagation in atomic clouds is generalized to short pulse regime by taking into account group velocity dispersion. It is shown that the number of stored pulses in the condensate can be optimized for a particular coupling laser power, temperature and interatomic interaction strength. Analytical results are derived for semi-ideal model of the condensate using effective uniform density zone approximation. Detailed numerical simulations are also performed. It is found that axial density profile of the condensate protects the pulse against the group velocity dispersion. Furthermore, taking into account finite radial size of the condensate, multi-mode light propagation in atomic Bose-Einstein condensate is investigated. The number of modes that can be supported by a condensate is found. Single mode condition is determined as a function of experimentally accessible parameters including trap size, temperature, condensate number density and scattering length. Quantum coherent atom-light interaction schemes are proposed for enhancing multi-mode light propagation effects.Comment: 12pages. Laser Physics, in pres

Dark States and Coherent Control of Spin States in Molecular Magnets

We propose a scheme to realize coherent control of spin states of molecule magnet, Ni$_4$. We introduce transverse magnetic fields with special frequencies. When the frequencies of transverse magnetic fields match in some conditions, we obtain dark states in Ni$_4$ molecules. Through adjusting the magnitude of magnetic fields, we can obtain any arbitrary superposition of the two ground spin states of Ni$_4$ molecules.Comment: 7 pages, 4 figures. To appear in Physical Review

Enhancement of field generation via maximal atomic coherence prepared by fast adiabatic passage in Rb vapor

We have experimentally demonstrated the enhancement of coherent Raman scattering in Rb atomic vapor by exciting atomic coherence with fractional stimulated Raman adiabatic passage. Experimental results are in good agreement with numerical simulations. The results support the possibility of increasing the sensitivity of CARS by preparing atomic or molecular coherence using short pulses

РОЛЬ СУЧАСНИХ ІНФОРМАЦІЙНИХ ТЕХНОЛОГІЙ У ЗАБЕЗПЕЧЕННІ ЯКОСТІ МЕДИЧНОЇ ОСВІТИ

The aim of the work –  to improve the quality of medical education through the use of modern information technologies. The main body. The article presents the role of modern information technologies in ensuring the quality of medical education. The reform of the health care system requires consistent changes in the training of a modern specialist with an appropriate level of competence, knowledge of the theoretical knowledge and practical skills prepared for market relations in the field of medical services provision. One of the most important prerequisites for ensuring the quality of higher medical education is the introduction of a new level of e-learning or “open learning” in the educational process, which is especially important for the training of a modern specialist. Conclusion. In order to improve the quality of medical education, it is necessary to take into account certain peculiarities of medical e-education, in particular its practical content, standardization of decision-making in the medical and diagnostic direction (protocols of medical aid provision), strengthening of the requirements for acquiring skills of the manager of the medical industry, readiness for work in the labor market and medical services.Мета роботи – з’ясувати вплив інформаційних технологій у трансформації післядипломної медичної освіти. Основна частина. У статті наведено роль сучасних інформаційних технологій у  забезпеченні якості медичної освіти. Реформа системи охорони здоров’я потребує послідовних змін у підготовці сучасного фахівця з належним рівнем компетентностей, володіння теоретичними знаннями та практичними навичками, підготовленого до ринкових відносин у питаннях надання медичних послуг. Однією з важливих передумов забезпечення якості вищої медичної освіти є впровадження в навчальний процес електронної освіти (e-learning) нового рівня або «відкритого навчання», що є особливо важливим для підготовки сучасного фахівця. Висновок. З метою поліпшення якості медичної освіти необхідне урахування певних особливостей медичної електронної освіти, зокрема її практично-орієнтованого змісту, стандартизації прийняття рішень лікувально-діагностичного спрямування (протоколи надання медичної допомоги), посилення вимог до набуття навичок менеджера медичної галузі, готовності до роботи на ринку праці та медичних послуг

Method of shifting and fixing optical frequency of an optical resonator, and optical resonator made by same

A method of shifting and fixing an optical frequency of an optical resonator to a desired optical frequency, and an optical resonator made by such a method are provided. The method includes providing an optical resonator having a surface and a refractive index, and obtaining a coating composition having a predetermined concentration of a substance and having a refractive index that is substantially similar to the refractive index of the optical resonator. The coating composition inherently possesses a thickness when it is applied as a coating. The method further includes determining a coating ratio for the surface of the optical resonator and applying the coating composition onto a portion of the surface of the optical resonator based upon the determined coating ratio

Polarization squeezing with cold atoms

We study the interaction of a nearly resonant linearly polarized laser beam with a cloud of cold cesium atoms in a high finesse optical cavity. We show theoretically and experimentally that the cross-Kerr effect due to the saturation of the optical transition produces quadrature squeezing on both the mean field and the orthogonally polarized vacuum mode. An interpretation of this vacuum squeezing as polarization squeezing is given and a method for measuring quantum Stokes parameters for weak beams via a local oscillator is developed

Trace formula for dielectric cavities II: Regular, pseudo-integrable, and chaotic examples

Dielectric resonators are open systems particularly interesting due to their wide range of applications in optics and photonics. In a recent paper [PRE, vol. 78, 056202 (2008)] the trace formula for both the smooth and the oscillating parts of the resonance density was proposed and checked for the circular cavity. The present paper deals with numerous shapes which would be integrable (square, rectangle, and ellipse), pseudo-integrable (pentagon) and chaotic (stadium), if the cavities were closed (billiard case). A good agreement is found between the theoretical predictions, the numerical simulations, and experiments based on organic micro-lasers.Comment: 18 pages, 32 figure

Selective addressing of high-rank atomic polarization moments

We describe a method of selective generation and study of polarization moments of up to the highest rank $\kappa=2F$ possible for a quantum state with total angular momentum $F$. The technique is based on nonlinear magneto-optical rotation with frequency-modulated light. Various polarization moments are distinguished by the periodicity of light-polarization rotation induced by the atoms during Larmor precession and exhibit distinct light-intensity and frequency dependences. We apply the method to study polarization moments of $^{87}$Rb atoms contained in a vapor cell with antirelaxation coating. Distinct ultra-narrow (1-Hz wide) resonances, corresponding to different multipoles, appear in the magnetic-field dependence of the optical rotation. The use of the highest-multipole resonances has important applications in quantum and nonlinear optics and in magnetometry.Comment: 5 pages, 6 figure