Fig. 2

Schematic of the optical set up. ND = Neutral Density filter; SiPM = Silicon Photo Multiplier detector; TCSPC = Time-Correlated Single-Photon Counting board.

Schematic of the optical set up. ND = Neutral Density filter; SiPM = Silicon Photo Multiplier detector; TCSPC = Time-Correlated Single-Photon Counting board.