1. Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, P. R. China
2. Department of Mechanical Engineering, Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Hong Kong 999077, P. R. China
3. College of Science, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China