1. Laboratory of Optical Physics,
Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190, China
2. The
Wallace H.
Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
3. School of Chemistry
and
Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
4. Department
of Physics, Guizhou University, Guiyang 550025, China