1Jiangsu Key Laboratory of Advanced Laser Materials and Devices, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
2Jiangsu Collaborative Innovation Center of Advanced Laser Technology and Emerging Industry, Jiangsu Normal University, Xuzhou 221116, China
3e-mail: weizhou@jsnu.edu.cn
4Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China