1. Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, United States
2. Advanced Photonics Center, Southeast University, Nanjing 210096, China
3. Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, United States
4. Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
5. Center for Biophotonics Science and Technology, University of California, Davis, Sacramento, California, United States