1. Department of Physics, Ludwig-Maximilians-Universität Munich, D-85748 Garching, Germany
2. Max Planck Institute of Quantum Optics, D-85748 Garching, Germany
3. Department of Physics, American University of Sharjah, Sharjah POB26666, United Arab Emirates
4. Department of Physics, The University of Jordan, Amman 11942, Jordan
5. School of Nuclear Science and Technology, Lanzhou University, 730000 Gansu, China
6. Inamori School of Engineering, The New York State College of Ceramics at Alfred University, Alfred, New York 14802, United States
7. Macromolecular Chemistry Department, Technical University Darmstadt, D-64287 Darmstadt, Germany
8. Chair in Polymer Chemistry, Saarland University, D-66123 Saarbrücken, Germany
9. Department of Physics, Escuela Politécnica Nacional, Ladron de Guevara E11-253, Ap. 1708266 Quito, Ecuador