Optical fiber

An Optical fiber (or optical fibre) is a flexible, transparent fiber made of high quality extruded glass (silica) or plastic, slightly thicker than a human hair. It can function as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication.

3 Different Speed of Optical fiber

Advantages :-

• Bandwidth - Fibre optic cables have a much greater bandwidth than metal cables. The amount of information that can be transmitted per unit time of fibre over other transmission media is its most significant advantage. With the high performance single mode cable used by telephone industries for long distance telecommunication, the bandwidth surpasses the needs of today's applications and gives room for growth tomorrow.
• Low Power Loss - An optical fibre offers low power loss. This allows for longer transmission distances.  In comparison to copper; in a network, the longest recommended copper distance is 100m while with fibre, it is 2000m. 
• Interference - Fibre optic cables are immune to electromagnetic interference. It can also be run in electrically noisy environments without concern as electrical noise will not affect fibre.
• Size - In comparison to copper, a fibre optic cable has nearly 4.5 times as much capacity as the wire cable has and a cross sectional area that is 30 times less. 
• Weight - Fibre optic cables are much thinner and lighter than metal wires.  They also occupy less space with cables of the same information capacity.  Lighter weight makes fibre easier to install. 
• Safety - Since the fibre is a dielectric, it does not present a spark hazard. 
• Security - Optical fibres are difficult to tap.  As they do not radiate electromagnetic energy, emissions cannot be intercepted.  As physically tapping the fibre takes great skill to do undetected, fibre is the most secure medium available for carrying sensitive data. 
• Flexibility - An optical fibre has greater tensile strength than copper or steel fibres of the same diameter.  It is flexible, bends easily and resists most corrosive elements that attack copper cable. 
• Cost - The raw materials for glass are plentiful, unlike copper.  This means glass can be made more cheaply than copper.

Disadvantages :

• Cost - Cables are expensive to install but last longer than copper cables.
• Transmission - Transmission on optical fibre requires repeating at distance intervals. 
• Fragile - Fibres can be broken or have transmission loses when wrapped around curves of only a few centimetres radius. However by encasing fibres in a plastic sheath, it is difficult to bend the cable into a small enough radius to break the fibre. 
• Protection - Optical fibres require more protection around the cable compared to copper.