1. Centre for OptoElectronics and Biophotonics (COEB), School of Electrical and Electronic Engineering, The Photonics Institute (TPI), Nanyang Technological University Singapore, 50 Nanyang Avenue, Singapore 639798
2. School of Electrical Sciences, Indian Institute of Technology Goa, Goa 403401, India
3. Temasek Laboratories, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
4. Key Laboratory of Advanced Transducers and Intelligent Control System, Ministry of Education, and Shanxi Province, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China