1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
2. Center for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore 639798 Singapore
3. Natural Sciences and Science Education National Institute of Education Nanyang Technological University Singapore 637616 Singapore
4. Department of Electronic Devices and Engineering Graduate School of Science and Engineering Yamaguchi University Ube 755–8611 Japan
5. Department of Physics and Information Technology Faculty of Computer Science and System Engineering Kyushu Institute of Technology Iizuka 820–8502 Japan