As expected, sensor 3, which present higher grooves
depth imposes a higher optical signal loss per groove. For
sensors 1 and 2, although the groves are produced at different
spacing on the POF, they present a similar optical loss
per groove, due to the similar depth and to the low
propagation attenuation (0.2 dB/m).
An average optical power loss of 3.4 ± 0.2% is noticed on
the transmitted signal, for each sliced groove, for sensors 1
and 2. For sensor 3 the average optical power loss was
7.5 ± 0.2% per groove (see Table 2).