1. Department of Chemistry City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China
2. State Key Laboratory of Terahertz and Millimeter Waves City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China
3. Center for Functional Photonics City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China