The cladding has a lower refractive index than the core. This causes Total Internal Reflection within the core. Most fibers operate in duplex pairs: one fiber is used to transmit and the other is used to receive. But it is possible to send both signals over a single strand. There are two main types of fiber optic cables: Single Mode Fiber (SMF) and Multi-Mode Fiber (MMF).
The difference is basically in the size of the core. MMF has a much wider core, allowing multiple modes (or “rays”) of light to propagate. SMF has a very narrow core which allows only a single mode of light to propagate. Each type of fiber has different properties with its own advantages and disadvantages.
Why use optic fiber cable?
- They have practically unlimited information
- They have high carrying capacity (very broad bandwidth, THz or Tbits/s)
- They have very low transmission losses (<0.2dB/km, cf1dB/km microwave, 10db/km twisted copper pair)
- They do not dissipate heat
- They are immune to cross-talk and electromagnetic interference
Optical fibers are suited for medical use. They can be made in flexible strands, extremely thin for insertion into the lungs, blood vessels, and many hollow parts of the body. These optical fibers are utilized in several instruments that allow doctors to observe internal body parts without performing any surgery.
Optic Fiber is installed and used for receiving and transmitting purposes. Telephone transmission uses fiber optic cables. These fibers transmit energy in the form of light pulses. Its technology is comparable to that of the coaxial cables, apart from that the optical fibers are able to handle thousands of conversations concurrently.
Optic fibers are used to connect servers and users in a variety of network settings and also help in increasing the accuracy and speed of data transmission.
Fibers are used for imaging in reach areas, such as sensory devices to make temperature, as wiring where EMI is an issue, pressure, as wiring in industrial settings and automobiles. Broadcast/CATV Cable companies use fiber optic cables for wiring HDTV, CATV, video-on-demand, the internet and many other applications.
They are used as hydrophones for SONAR and seismic uses, such as wiring in submarines, aircraft, and other vehicles.
Fiber cables are used for data storage as well as transmission.
Fiber optic cables are also used for imaging and lighting and as sensors to monitor and measure a vast array of variables. Furthermore, fiber cables are used in development, research and testing across all the aforementioned applications.