optical repeater (OR)
The optical repeater (OR) is used to compensate for attenuation of the light signal of the transmission link.
Although the range ofoptical fibers, especially that of monomode fibers, is extraordinarily long, the signal must be amplified and regenerated by an optical repeater at certain intervals for very long transmission distances, such as those found in optical networks and in submarine cables.
From the function, the optical repeater converts the optical signal into an electrical signal in an O/E converter. It then amplifies the electrical signal, which is then converted back into an optical signal in an E/O converter and fed into the next optical transmission link. The conversion of the optical signal into an electrical signal takes place in a photodiode or a phototransistor, the opposite conversion of the electrical signal into an optical signal takes place in a light-emitting di ode or a laser diode.