Optical Communication is the most modern mode of wired communication.
Optical communication is also the youngest mode of communication. However its capabilities supersede all other modes of communication.
Before optical communication the most of the communication was in radio and microwave domain which has frequency range orders of magnitude lower than the optical see Fig for the electromagnetic spectrum.
For good communication a system needs to have following things.
(1)
Bandwidh (BW)
(2)
Good signal to noise ratio (SNR) i.e. low loss
Since the bandwidth of a system is more or less proportional to the frequency of operation, use of higher frequency facilitates larger BW.
The BW at optical frequencies is expected to be 3 to 4 orders of magnitude higher than that at the microwave f requencies (1GHz to 100GHz).
