1 Opto-Electronics and Measurement Techniques, University of Oulu, P.O. Box 4500, Oulu, 90014, Finland.
2 Opto-Electronics and Measurement Techniques, University of Oulu, P.O. Box 4500, Oulu, 90014, Finland. alexey.popov@oulu.fi.
3 Opto-Electronics and Measurement Techniques, University of Oulu, P.O. Box 4500, Oulu, 90014, Finland. igor.meglinski@oulu.fi.
4 Interdisciplinary Laboratory of Biophotonics, National Research Tomsk State University, Tomsk, 634050, Russia. igor.meglinski@oulu.fi.
5 National Research Nuclear University - MEPhI, Institute of Engineering Physics for Biomedicine (PhysBio), Moscow, 115409, Russia. igor.meglinski@oulu.fi.