[1] Czech Acad Sci, Inst Sci Instruments, Kralovopolska 147, Brno 61264, Czech Republic
[2] Leibniz Inst Photon Technol, Albert Einstein Str 9, D-07745 Jena, Germany
[3] Czech Acad Sci, Inst Biophys, Kralovopolska 135, Brno 61265, Czech Republic
[4] Friedrich Schiller Univ Jena, Inst Appl Opt, Frobelstieg 1, D-07743 Jena, Germany