1. State Key Lab of Modern Optical Instrumentation College of Optical Science and Engineering Zhejiang University Hangzhou 310027 P. R. China
2. School of Materials Science and Engineering Zhejiang University Hangzhou 310027 P. R. China
3. National Institute of Advanced Industrial Science and Technology Osaka 563‐8577 Japan
4. CAS Center for Excellence in Ultra‐intense Laser Science Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 P. R. China