...
Optical Device
The general definition of an optical device is that it creates , manipulates or measures the electromagnetic radiation. There are hundred of practical applications related to field of optics but keeping in view the scope of our question , we will stick with the devices that deals with optical data transmission.
Optical Data Transmission
...
The transmitter and how a signal travels in the an optical fibre fiber can be visualized as:-
Figure 1: Light travelling inside an optical fiber
...