1. NSF Nanoscale Science and Engineering Center (NSEC), 3112 Etcheverry Hall, University of California, Berkeley, California 94720, United States
2. Waitt
Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, San Diego, California 92037, United States
3. Department
of Mechanical and Industrial Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
4. Department
of Electrical and Computer Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
5. Materials
Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron
Road, Berkeley, California 94720, United States