1. Nanophotonic
Laboratory, Department of Physics, Nanjing University of Science and Technology, Nanjing 210094, China
2. Centre
for Disruptive Photonic Technologies, School of Physical and Mathematical
Sciences, Nanyang Technological University, 1 Nanyang Walk, Blk 5 Level 3, Singapore 637371, Singapore
3. Institute
of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602, Singapore
4. School
of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
5. Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore