1. Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
2. Institute
of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
3. Center for Integrated
Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, United States