What is fiber optics?

Fiber optics, or optical fiber, refers to the technology that transmits information as light pulses along a glass or plastic fiber.

A fiber optic cable can contain a varying number of these glass fibers — from a few up to a couple hundred. Another glass layer, called cladding, surrounds the glass fiber core. The buffer tube layer protects the cladding, and a jacket layer acts as the final protective layer for the individual strand.

Fiber optic cables are commonly used because of their advantages over copper cables. Some of those benefits include higher bandwidth and transmit speeds.

Fiber optics is used for long-distance and high-performance data networking. It is also commonly used in telecommunication services, such as internet, television and telephones. For example, Verizon and Google use fiber optics in their Verizon FIOS and Google Fiber services, respectively, providing Gigabit internet speeds to users.
How fiber optics works

Fiber optics transmit data in the form of light particles — or photons — that pulse through a fiber optic cable. The glass fiber core and the cladding each have a different refractive index that bends incoming light at a certain angle.

When light signals are sent through the fiber optic cable, they reflect off the core and cladding in a series of zig-zag bounces, following a process called total internal reflection. The light signals do not travel at the speed of light because of the denser glass layers, instead traveling about 30% slower than the speed of light.

To renew, or boost, the signal throughout its journey, fiber optics transmission sometimes requires repeaters at distant intervals. These repeaters regenerate the optical signal by converting it to an electrical signal, processing that electrical signal and retransmitting the optical signal.

Fiber optic cables are now able to support up to 10 Gbps signals. Typically, as the bandwidth capacity of a fiber optic cable increases, the more expensive it becomes.

Types of fiber optic cables

Multimode fiber and single-mode fiber are the two primary types of fiber optic cable.
Single-mode fiber

Single-mode fiber is used for longer distances due to the smaller diameter of the glass fiber core. This smaller diameter lessens the possibility for attenuation, which is a reduction in signal strength. The smaller opening isolates the light into a single beam, offering a more direct route and enabling the signal to travel a longer distance.

Single-mode fiber also has a considerably higher bandwidth than multimode fiber. The light source used for single-mode fiber is typically a laser. Single-mode fiber is usually more expensive as it requires precise calculations to produce the laser light in a smaller opening.
Multimode fiber

Multimode fiber is used for shorter distances because the larger core opening enables light signals to bounce and reflect more along the way. The larger diameter permits multiple light pulses to be sent through the cable at one time, which results in more data transmission. This also means there is more possibility for signal loss, reduction or interference, however. Multimode fiber optics typically uses an LED to create the light pulse.

Sumber : techtarget.com