1. Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai 200093, P.R. China
2. Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, Braga 4715-330, Portugal
3. Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong 999077, Hong Kong S.A.R., P.R. China