Quantity   Component name
1 × PMMA 1mm diameter optical fiber This is a polymer optical fiber
1 × LED The light source. Any visible LED works.
1 × Phototransistor This is the light detector
1 × Arduino Nano Microcontroller used to control the LED and read the phototransistor
1 × Optical connector (LED) Used to couple the LED to the PMMA optical fiber
1 × Optical connector (phototransistor) Used to couple the PMMA fiber to the phototransistor
1 × Signal conditioning Electronic device used to condition the signal detected by the phototransistor