1 Key Laboratory of Optoelectronic Information Science and Technology of the Ministry of Education, Ultrafast Laser Laboratory, College of Precision Instruments and Optoelectronic Engineering, Tianjin University, Tianjin 300072, China
2 Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen, Guangdong 518060, China
3 Nanophotonics Research Centre, Shenzhen University, Shenzhen, Guangdong 518060, China