[1] Chongqing Univ, Coll Phys, Soft Matter & Interdisciplinary Res Ctr, Chongqing 400044, Peoples R China
[2] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Inst Phys, Beijing 100190, Peoples R China
[3] Chalmers Univ Technol, Dept Appl Phys, Div Bionanophoton, S-41296 Gothenburg, Sweden
[4] Leibniz Inst Photon Technol, D-07745 Jena, Germany
[5] Univ Jena, D-07743 Jena, Germany
[6] Natl Ctr Nanosci & Technol, Beijing 100190, Peoples R China