1. Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics; Huazhong University of Science and Technology; Wuhan 430074 China
2. Research-Educational Institute of Optics and Biophotonics; Saratov State University; Saratov 410012 Russia
3. Interdisciplinary Laboratory of Biophotonics; Tomsk State University; Tomsk 634050 Russia