1,418 research outputs found

    Frequency modulation and pulse compression by coherent multimode molecular motion

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    We study beating of a probe field with a time-varying susceptibility in a coherently prepared Raman medium. We consider the general case of an arbitrary variation of susceptibility, which corresponds to a superposition of an arbitrary number of excited Raman transitions. We derive a general analytical solution and conservation relations for this process. We show that the interference between Raman polarizations may substantially affect frequency modulation and pulse compression for the probe field.Comment: 4 pages, 4 figure

    Efficient channeling of fluorescence photons from single quantum dots into guided modes of optical nanofiber

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    We experimentally demonstrate the efficient channeling of fluorescence photons from single q-dots on optical nanofiber into the guided modes, by measuring the photon-count rates through the guided and radiation modes simultaneously. We obtain the maximum channeling efficiency to be 22.0 (\pm4.8)% at fiber diameter of 350 nm for the emission wavelength of 780 nm. The results may open new possibilities in quantum information technologies for generating single photons into single-mode optical-fibers.Comment: 5 pages, 4 figure

    Spontaneous radiative decay of translational levels of an atom near a dielectric surface

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    We study spontaneous radiative decay of translational levels of an atom in the vicinity of a semi-infinite dielectric. We systematically derive the microscopic dynamical equations for the spontaneous decay process. We calculate analytically and numerically the radiative linewidths and the spontaneous transition rates for the translational levels. The roles of the interference between the emitted and reflected fields and of the transmission into the evanescent modes are clearly identified. Our numerical calculations for the silica--cesium interaction show that the radiative linewidths of the bound excited levels with large enough but not too large vibrational quantum numbers are moderately enhanced by the emission into the evanescent modes and those for the deep bound levels are substantially reduced by the surface-induced red shift of the transition frequency

    Pyrmont-Ultimo Precinct (PUP) Scale Organics Management Scoping Study

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    This report, the “Pyrmont Ultimo Precinct (PUP) Scale Organics Management Scoping Study” has been prepared by the Institute for Sustainable Futures (ISF), University of Technology Sydney (UTS). The research, conducted by ISF and funded through a collaboration between Sydney Water Corporation (SWC) and the NSW Environment Protection Authority (EPA), has investigated at a high level, a suite of innovative organic waste management options that could potentially be piloted in Pyrmont-Ultimo, currently the densest urban area in Australia. The Pyrmont-Ultimo precinct (PUP), encompassing Pyrmont, Ultimo and the newly developed Central Park, has been specifically chosen due to the significant potential in the area, existing network of sustainability practitioners (i.e. Smart Locale1) and ISF’s/UTS’s direct involvement in research in food waste management

    Effect of an atom on a quantum guided field in a weakly driven fiber-Bragg-grating cavity

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    We study the interaction of an atom with a quantum guided field in a weakly driven fiber-Bragg-grating (FBG) cavity. We present an effective Hamiltonian and derive the density-matrix equations for the combined atom-cavity system. We calculate the mean photon number, the second-order photon correlation function, and the atomic excited-state population. We show that, due to the confinement of the guided cavity field in the fiber cross-section plane and in the space between the FBG mirrors, the presence of the atom in the FBG cavity can significantly affect the mean photon number and the photon statistics even though the cavity finesse is moderate, the cavity is long, and the probe field is weak.Comment: Accepted for Phys. Rev.

    Designing a NAABSA Class Tanker Ship with Bottom Protection from Ground

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    Indonesia is the world's largest archipelago country with a high potential for economic development and top producer and exporter of palm oil. As an archipelago country, the most efficient cargo transportation routes are through rivers and seas. Designing and building tankers, taking into account the specifics of the operation, are relevant. The paper considers the issues of designing a tanker for the transportation of crude palm oil with a defined operation area and route. The general concept of the vessel is proposed, taking into account the restrictions on the navigation area and draft for operation in the river. Particular attention is given to the issues of strengthening the hull in terms of overall longitudinal strength, as well as the bottom and the propeller-steering complex in terms of interaction with the ground. An external structural protection (ESP) from the ground was developed, and comparative calculations of the stress-strain state of the compartment and ESP structures were performed. The effectiveness of the solution for protecting the hull from direct contact with the ground is shown, and outlined ways for the possible development of tanker projects for the conditions
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