1. Guangdong Provincial Key Laboratory of Information Photonics Technology School of Materials and Energy Guangdong University of Technology Guangzhou Guangdong 510006 P. R. China
2. Institute of Nanophotonics Jinan University Guangzhou Guangdong 511443 P. R. China
3. Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics Technology Jinan University Guangzhou Guangdong 511443 P. R. China
4. Institute of Semiconductors South China Normal University Guangzhou Guangdong 510631 P. R. China
5. State Key Laboratory of Optoelectronic Materials and Technologies Nanotechnology Research Center School of Materials Science & Engineering Sun Yat‐sen University Guangzhou Guangdong 510275 P. R. China
6. Guangdong Provincial Key Laboratory of Chip and Integration Technology Guangzhou Guangdong 510631 P. R. China