Affiliation: | (1) University of Osnabrück, Department of Physics, D-49069 Osnabrück, Germany (Fax: +49–541/969–2670, E-mail: ekaterina.shamonina@physik.uni-osnabrueck.de), DE;(2) Friedrich-Schiller-University Jena, Department of Physics, D-07743 Jena, Germany, DE;(3) Applied Optics Group, Physics Laboratory, The University, Canterbury, Kent CT2 7NR, UK, GB |