1. MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China.
2. Department of Physics, University of Crete, Heraklion 71003, Greece.
3. Institut für Physik, Universität Rostock, 18059 Rostock, Germany.
4. Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia.
5. Institute of Electronic Structure and Laser (IESL)–FORTH, Heraklion 71110, Greece.
6. Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132, USA.