1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
2. College of Physics and Optoelectronic Engineering Harbin Engineering University Harbin 150001 China
3. School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore
4. Institute of Materials Research and Engineering A*STAR (Agency for Science Technology and Research) Singapore 138634 Singapore
5. School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore
6. CINTRA CNRS/NTU/THALES UMI 3288 Singapore 637553 Singapore
7. Guangdong Provincial Key Laboratory of Information Photonics Technology College of Information Engineering Guangdong University of Technology Guangzhou 510006 China
8. Department of Optical Devices Le Quy Don Technical University Hanoi 100000 Vietnam