1. Institute of Photonics
2. Faculty of Science
3. Ningbo University
4. Ningbo 31 5211
5. China
6. Department of Electronic Engineering
7. The Chinese University of Hong Kong
8. Hong Kong Special Administrative Region
9. Institute of Cybernetics “E. Caianiello” of CNR
10. Via Campi Flegrei 34
11. 80072 Pozzuoli
12. Italy