Hl6358mg

The setup was built around an area-scan CMOS camera (Basler acA2000-340 km; ROI set to 512 × 320 pixels, 200 fps) placed at 25 cm distance, imaging the index finger from the top. This camera was triggered via a microcontroller (STM32) that also controlled the timing of the applied LEDs and lasers (thereby synchronizing all system components). The laser driver was home-built using an iC-WJZ chip (iC Haus).
The camera was triggered at a framerate of 200 fps. Via time domain multiplexing, the camera framerate was equally distributed across 4 acquisition channels (each 50 fps). This enabled continuous video acquisition while multiplexing between different illumination modes and/or light source types. The following light source types were applied:

Red laser diode (Thorlabs HL6358MG—639 nm, 10 mW, Ø5.6 mm);

NIR laser diode (Thorlabs L850P010—850 nm, 10 mW, Ø5.6 mm);

Red LED (Wurth Elektronik 150141SS63140—640 nm, 196 mW);

NIR LED (Vishay TSHG6200—850 nm, 180 mW).

The camera images were stored in a desktop computer using full camera-link communication, as detailed in Figure 1.

The fluorescence quantum yields were measured and determined according to the procedure described in^{47 (link)}. The measurements on SCP were carried out at room temperature using a laser diode (Thorlabs, HL6358MG) operating at 639 nm as excitation light source. For detection a CCD-camera (ANDOR IDUS 420) that was connected to a spectrograph (MS125), which in turn was fibre-coupled to an integrating sphere was used.