1. Guangdong
Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, China
2. Guangdong
Key Laboratory of Optical Fiber Sensing and Communications, Institute
of Photonics Technology, Jinan University, Guangzhou 510632, China
3. Department
of Applied Physics, Hong Kong Polytechnic University, Hong Kong, People’s Republic of China
4. Department
of Electronics, Carleton University, Ottawa K1S5B6, Canada