1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
2. Interdisciplinary Center for Quantum Information State Key Laboratory of Modern Optical Instrumentation ZJU-Hangzhou Global Science and Technology Innovation Center Zhejiang University Hangzhou 310027 China
3. Centre for Disruptive Photonic Technologies Nanyang Technological University Singapore 637371 Singapore