1. Department of Physics, Kent State University, Kent OH
2. Unit of Electro-Optical Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel
3. Department of Physics, Ben-Gurion University of the Negev, Beer Sheva, Israel
4. Institute of Physics of National Academy of Science, Kyiv, Ukraine
5. Division of Research and Department of Physics, University at Albany, Albany, NY