1 State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
2 School of Economics and Commerce, South China University of Technology, Guangzhou 510640, China
3 Laboratory of Biomedical Photonics & Engineering, School of Basic Medical Sciences, Guangxi Medical University, Nanning 530021, China
4 Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353, USA
5 Life Science Institute and Laboratory of Biomedical Photonics & Engineering, Guangxi Medical University, Nanning 530021, China