1. Guangxi Academy of Sciences, Laboratory of Biophysics, 98 Daling Road, Nanning, Guangxi 530007, China
2. Washington University in St. Louis, Department of Biomedical Engineering, Optical Imaging Laboratory, One Brookings Drive, Campus Box 1097, St. Louis, Missouri 63130, United States
3. East Carolina University, Department of Physics, East 5th Street, Greenville, North Carolina 27858, United States