Different cables
There is different types of network cables like Optical cable, Coaxial cable and twisted pair cable.
The optical cable is made up of strands of incredibly thin optically pure glass that carry digital information with light instead of electrical currents used with Ethernet. There are two basic types of fiber optic cable: single-mode and multi-mode. Single-mode fiber cables use laser light to send signals, and they are thinner than multi-mode fiber cables. Light-emitting diodes (LEDs) are used to send signals in multi-mode fiber cables, and multi-mode cables are usually used over short distances. Data transfer rates between 10 Mbps to 10 gigabytes per second (Gbps) are the norm.
Twisted pair cabling is a form of wiring in which pairs of wires (the forward and return conductors of a single circuit) are twisted together for the purposes of canceling out electromagnetic interface (EMI) from other wire pairs and from external sources. This type of cable is used for home and corporate Ethernet networks. There are two types of twisted pair cables: shielded, unshielded.
Coaxial lines confine the electromagnetic wave to area inside the cable, between the center conductor and the shield. The transmission of energy in the line occurs totally through the dielectric inside the cable between the conductors. Coaxial lines can therefore be bent and twisted (subject to limits) without negative effects, and they can be strapped to conductive supports without inducing unwanted currents in them and though. The most common use for coaxial cables is for television and other signals with bandwidth of multiple megahertz.
Why to use optical cables? What is the advantage of using optical fiber and why do we use them?
Optical cables transfer data fast and they are more efficient and secure for network applications. Optical cables can transmit a lot of information. It has the added benefit of security for the data being transmitted.
Traditional copper wires transmit electrical currents, while fibre optic technology sends pulses of light generated by a light emitting diode or laser along optical fibres.
Why do the light signals stay in the optical cable?
Light travels down a fiber-optic cable by bouncing repeatedly off the walls. Each tiny photon (particle of light) bounces down the pipe like a bobsleigh going down an ice run. If light hits glass at a really shallow angle (less than 42 degrees), it reflects back in again—as though the glass were really a mirror. This phenomenon is called total internal reflection. It's one of the things that keeps light inside the pipe. The other thing that keeps light in the pipe is the structure of the cable, which is made up of two separate parts. The main part of the cable in the middle is called the core and that's the bit the light travels through. Wrapped around the outside of the core is another layer of glass called the cladding. The cladding's job is to keep the light signals inside the core. It can do this because it is made of a different type of glass to the core. More technically, the cladding has a higher refractive index than the core. Light travels slower in the cladding than in the core. Any light that tries to leak into the cladding tends to bend back inside the core.
Why can you send more data through an optical cable than a copper cable?
Traditional copper wires transmit electrical currents, while fibre optic technology sends pulses of light generated by a light emitting diode or laser along optical fibres.
Why the information is more secured via optical cables?
Information sent via fiber optic cables is much more difficult to intercept because light can’t be read in the same way signals sent via copper cabling can be.
References:
1. http://www.businessbee.com/resources/news/operations-buzz/buzzbattle-ethernet-vs-fiber-basics/
2. http://en.wikipedia.org/wiki/Networking_cables
3. http://www.abc.net.au/science/articles/2010/10/21/3044463.htm