Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics – Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 P. R. China

Department of Applied Physics, John A. Paulson School of Engineering and Applied Sciences, Harvard University Cambridge, MA, 02138 USA