1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
2. Centre for Disruptive Photonic Technologies The Photonics Institute Nanyang Technological University Singapore 639798 Singapore
3. Ioffe Institute St Petersburg 194021 Russia
4. ITMO University St Petersburg 197101 Russia
5. Nonlinear Physics Center Australian National University Canberra ACT 2601 Australia