Author Affiliations

J. M. Sanz,^a D. Ortiz,^a R. Alcaraz de la Osa,^a J. M. Saiz,^a F. González,^a A. S. Brown,^b M. Losurdo,^c H. O. Everitt,^d,e and F. Moreno^a

^aGroup of Optics, Department of Applied Physics, University of Cantabria, Avda de Los Castros s/n 39005 Santander, Spain.

^bDepartment of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States.

^cInstitute of Inorganic Methodologies and of Plasmas-CNR, and INSTM, Via Orabona, 4-70126 Bari, Italy.

^dU.S. Army Aviation & Missile RD&E Center, Redstone Arsenal, AL 35802 USA.

^eDepartment of Physics, Duke University, Durham, NC 27708 USA.