As they are not electrically conductive , hence very suitable for use in areas where electrical isolation and interference are severe problems.
An attenuation of less than 2dB/Km .
Advantages of Optical Communications 1) Extremely wide system bandwidth - up to 10 GHz is possible 2) Immunity to EMI - such as lightning, electric motors, fluorescent lights 3) Virtual elimination of cross-talk 4) Lower signal attenuation than other propagation systems
Advantages of Optical Communications 5) Lighter weight and smaller size 6) Lower cost 7) Conversion of the earth’s resources - principal ingredient in glass is sand which is cheap and virtually unlimited supply 8) Safety - no hazard of short circuits nor spark will exist in optical fiber
Light travels at approximately 3x10 8 m/s in free space and slower in a material denser than free space . This reduction in speed as it passes from free space into a denser material results in refraction of the light .
Sshows the light is bent at the interface. The degree to which the ray is bent depends on the index of refraction n of the denser material .