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Optical Field (optical + field)
Selected AbstractsFabrication of near-field optical apertures in aluminium by a highly selective corrosion process in the evanescent fieldJOURNAL OF MICROSCOPY, Issue 3 2003D. Haefliger Summary A simple, one-step process to fabricate high-quality apertures for scanning near-field optical microscope probes based on aluminium-coated silicon nitride cantilevers is presented. A thin evanescent optical field at a glass,water interface was used to heat the aluminium at the tip apex due to light absorption. The heat induced a breakdown of the passivating oxide layer and local corrosion of the metal, which selectively exposed the front-most part of the probe tip from the aluminium. Apertures with a protruding silicon nitride tip up to 72 nm in height were fabricated. The height of the protrusion was controlled by the extent of the evanescent field, whereas the diameter depended on the geometry of the probe substrate. The corrosion process proved to be self-terminating, yielding highly reproducible tip heights. Near-field optical resolution in a transmission mode of 85 nm was demonstrated. [source] A multi-mode model of a non-classical atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed lightLASER PHYSICS LETTERS, Issue 12 2005S. A. Haine Abstract We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We introduce a method which allows us to model the full multimode dynamics of the squeezed optical field and the outcoupled atoms. We show that for experimentally reasonable parameters that the quantum statistics of the optical field are almost completely transferred to the outcoupled atoms, and investigate the robustness to the coupling strength and the two-photon detuning. [source] High-contrast dark resonance in ,+ , ,, optical fieldLASER PHYSICS LETTERS, Issue 10 2004S. V. Kargapoltsev Abstract The amplitude of , resonance in alkali atoms is limited by perturbing cycling transitions in the case of D2 line or by existence of additional trapping states in the case of D1 line. We propose to eliminate these extra trapping states by using two counter-propagating bichromatic fields of orthogonal circular polarizations. The experiment is in accordance with the theoretical proposal. The result refers to small-size cells and is important for applications in miniaturized atomic clocks. (© 2004 by ASTRO, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Towards high-fidelity two-photon quantum communicationsFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 4-5 2003G. Kurizki We propose two alternative scheme for highly efficient nonlinear interaction between weak optical fields. The first scheme is based on the attainment of electromagnetically induced transparency simultaneously for two fields via transitions between magnetically split F = 1 atomic sublevels, in the presence of two driving fields. The second scheme relies on simultaneous electromagnetically- and self-induced transparencies of the two fields. Thereby, equal slow group velocities and giant cross-phase modulation of the weak fields over long distances are achieved. [source] Le coup d',il du spectateur: Spectatorial Function and Stage Space in French Theatre Design, 1760-1784JOURNAL FOR EIGHTEENTH-CENTURY STUDIES, Issue 4 2009PANNILL CAMP Abstract The sightlines which architects such as Oppenord and Roubo the Younger drew on their theatre plans demonstrate an attempt to align stage spaces and optical fields. Indeed, the reform-minded architects of the period 1748 to 1784 applied geometrical forms to their plans, and adopted a terminology borrowed from optics, the science of light and vision. In focusing specifically on the theoretical texts and architectural drawings published between 1765 and 1784, we argue that this use of optical space indicates a dislocation between, on the one hand, the spatial representation which the French reformers promoted in their drawings and, on the other, stage perspective, which had, since the previous century, been associated with the influence of the Italian Baroque. In the 1780s, architects gradually abandoned the use of stage perspective, preferring instead a theatrical space modelled after an ostensibly natural optical encounter. [source] Optical probing and imaging of live cells using SERS labelsJOURNAL OF RAMAN SPECTROSCOPY, Issue 1 2009Janina Kneipp Abstract During surface-enhanced Raman scattering (SERS), molecules exhibit a significant increase in their Raman signals when attached, or in very close vicinity, to gold or silver nanostructures. This effect is exploited as the basis of a new class of optical labels. Here we demonstrate robust and sensitive SERS labels as probes for imaging live cells. These hybrid labels consist of gold nanoparticles with Rose Bengal or Crystal Violet attached as reporter molecules. These new labels are stable and nontoxic, do not suffer from photobleaching, and can be excited at any excitation wavelength, even in the near infrared. SERS labels can be detected and imaged through the specific Raman signatures of the reporters. In addition, surface-enhanced Raman spectroscopy in the local optical fields of the gold nanoparticles also provides sensitive information on the immediate molecular environment of the label in the cell and allows imaging of the native constituents of the cell. This is demonstrated by images based on a characteristic Raman line of the reporter as well as by displaying lipids based on the SERS signal of the CH deformation/bending modes at ,1470 cm,1. Copyright © 2008 John Wiley & Sons, Ltd. [source] Near-field mapping of surface refractive-index distributionsLASER PHYSICS LETTERS, Issue 9 2005I.P. Radko Abstract Scanning near-field optical microscopy (SNOM) in reflection is employed for high-resolution mapping of surface refractive-index distributions. Two different single-mode optical fibers with step-index profiles are characterized using a reflection SNOM setup, in which cross-polarized detection is employed to increase the contrast in optical images and, thereby, the method sensitivity. The SNOM images exhibit a clear ring-shaped structure associated with the fiber step-index profile, indicating that surface refractive-index variations being smaller than 10,2 can be detected. It is found that the quantitative interpretation of SNOM images requires accurate characterization of a fiber tip used, because the detected optical signal is a result of interference between the optical fields reflected by the sample surface and by the fiber tip itself. The possibilities and limitations of this experimental technique are discussed. (© 2005 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] | ||||||||||