Lichtkraft-Lithographie mit Atomen. Teilvorhaben: Lichtkraftlithographie mit optischen Gittern Abschlussbericht

State-of-the-art: Until 1995 the generation of stable, periodic structures made of Chromium and Aluminum by optical lithography has been demonstrated by U.S. research groups. Scope of the present study/research: The scope of the present study has been the development of methods to generate and stabilize lateral nanostructures made by light forces, as well as the demonstration of methods to localize neutral atoms in optical lattices. Method: Atoms of a high density thermal atomic beam have been forced to interact with an optical lattice or optical standing wave. The neutral atoms have been focussed on a substrate to generate one or two-dimensional nanostructures. Results: A method to generate intense optical light fields in standing waves has been developed which can be applied in atom lithography. The localization of the atoms in the light field has been demonstrated by Bragg diffraction. Techniques to transfer a pattern into a stable structure have been provided as an positive and negative image of the original physical mask. Summary/Possible applications: The development of methods to transfer chemical active nanostructures into a metal surface may be a progress, not only for lithography by light forces. The novel process of pattern transfer enables the use of inexpensive and compact laser diode systems for the generation of nanostructures in atom lithography, which is important with respect to possible, further industrial applications. (orig.)SIGLEAvailable from TIB Hannover: DtF QN1(68,20) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Sensitive and simple frequency comb fourier transform spectrometer with a multipass cell

Item does not contain fulltextCLEO 201

Quantum interference and non-linear spectroscopy Final report

An experimental and theoretical program aimed at investigating the quantum coherence induced effects in an atomic system, was carried out. The experimental program was carried out on both cesium and rubidium atomic systems, in which we probed the effects of coherences between various atomic states. These coherences were found to influence the optical pumping properties and the population transfer mechanisms in these systems. The experiments probed these properties in both an atomic beam and in an optically created cold atomic lattice. Using a unique method, we optically pumped Cs in an atomic beam into a single quantum state, thus allowing us to prepare a spin aligned system. Once in a single quantum state, the atom was then available for further interaction with a laser, and we were able to study the evolution of the atomic state coherences. The dependence of the coherence on laser linewidth, external magnetic field and laser polarization was examined both theoretically and experimentally. We also developed a single mode diode laser for operation at 895 nm for probing the cesium D_1 line, for which laser diodes were until now not accessible. In another experiment, on laser cooled rubidium atoms, we probed the atomic lattice by Bragg diffraction of coherent light. By an additional probe spectroscopy we could probe the minute atomic motions of an atom deeply bound in a potential well. (orig.)SIGLEAvailable from TIB Hannover: F98B1587 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekGerman-Israeli Foundation for Scientific Research and Development (GIF), Oberschleissheim (Germany)DEGerman

Routine diagnostics for neural antibodies, clinical correlates, treatment and functional outcome.

To determine frequencies, interlaboratory reproducibility, clinical ratings, and prognostic implications of neural antibodies in a routine laboratory setting in patients with suspected neuropsychiatric autoimmune conditions. Earliest available samples from 10,919 patients were tested for a broad panel of neural antibodies. Sera that reacted with leucine-rich glioma-inactivated protein 1 (LGI1), contactin-associated protein-2 (CASPR2), or the voltage-gated potassium channel (VGKC) complex were retested for LGI1 and CASPR2 antibodies by another laboratory. Physicians in charge of patients with positive antibody results retrospectively reported on clinical, treatment, and outcome parameters. Positive results were obtained for 576 patients (5.3%). Median disease duration was 6 months (interquartile range 0.6-46 months). In most patients, antibodies were detected both in CSF and serum. However, in 16 (28%) patients with N-methyl-D-aspartate receptor (NMDAR) antibodies, this diagnosis could be made only in cerebrospinal fluid (CSF). The two laboratories agreed largely on LGI1 and CASPR2 antibody diagnoses (κ = 0.95). The clinicians (413 responses, 71.7%) rated two-thirds of the antibody-positive patients as autoimmune. Antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), NMDAR (CSF or high serum titer), γ-aminobutyric acid-B receptor (GABABR), and LGI1 had ≥ 90% positive ratings, whereas antibodies against the glycine receptor, VGKC complex, or otherwise unspecified neuropil had ≤ 40% positive ratings. Of the patients with surface antibodies, 64% improved after ≥ 3 months, mostly with ≥ 1 immunotherapy intervention. This novel approach starting from routine diagnostics in a dedicated laboratory provides reliable and useful results with therapeutic implications. Counseling should consider clinical presentation, demographic features, and antibody titers of the individual patient