[1] Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA
[2] Tel Aviv Univ, Sch Elect Engn, Dept Phys Elect, Fac Engn, IL-6997801 Tel Aviv, Israel
[3] Tel Aviv Univ, Ctr Light Matter Interact, IL-6997801 Tel Aviv, Israel
[4] Univ Tarapaca, Inst Alta Invest, Casilla 7D, Arica, Chile
[5] Tech Univ Darmstadt, Inst Appl Phys, D-64289 Darmstadt, Germany
[6] Tel Aviv Univ, Sch Chem, IL-6997801 Tel Aviv, Israel
[7] Univ Massachusetts, Dept Phys, Boston, MA 02125 USA