1. State Key Laboratory on Tunable laser Technology, Ministry of Industry and Information Technology Key Lab of Micro‐Nano Optoelectronic Information System, Shenzhen Graduate School Harbin Institute of Technology Shenzhen 518055 P. R. China
2. Institut für Theoretische Physik, Otto‐von‐Guericke‐Universität Magdeburg, Postfach 4120 D‐39016 Magdeburg Germany
3. Department of Engineering Science and Physics College of Staten Island The City University of New York, Staten Island NY 10314 USA
4. The Graduate Center The City University of New York NY 10016 USA
5. Department of Optical Engineering Kongju National University Cheonan 330717 South Korea
6. Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan 030006 P. R. China
7. Department of Applied Physics Yale University New Haven CT 06520 USA