The basics of fiber optics that you must know

What is fiber optics?

Fiber optics, or optical fiber, refers to the medium and the technology of information transmission as light pulses along extremely thin strands of purified glass. Unlike copper wire, optical fiber does not use electricity during transmission.

Basic elements of fiber optics

1.        The core or the center of the optical fiber is a very thin strand of glass that carries the light signal.
2.        The cladding is the optical material which reflects the light signals back into the core. This prevents the light from escaping and allows it to travel through the fiber.
3.        The outside jacket or buffer coating is made of a plastic material that protects the optical fiber from any moisture, corrosion and external damage.

2 types of optical fiber

1.        Glass fibers, which are more common, because they allow longer distance transmission and they are more efficient.
2.        Plastic optical fibers are used in less technical applications and are normally used in very short-length transmissions.

What is fiber optic cable?

Fiber optic cables send digital data at the speed of light. A fiber optic cable can contain a varying number of these glass fibers -- from a few up to a couple hundred, so optical fiber is the core part of optical fiber cable.

2 types of fiber optic cables

There are two basic types of optical cable used for data and communications, single mode and multi-mode. The principle differences are core size and the distance signals can be carried. Fiber cable is measured by its core and cladding diameter in micrometers (µm).

1.        Single mode

Single mode Fiber has a narrower core size of 8.3 µm. The core of the glass fiber is much thiner than in multi-mode fibers. Light thus travels parallel to the axis, creating little pulse dispersion. Data transmission modes are higher, and the distances that single mode fiber can cover can be over 50 times longer than multi-mode fibers. Duplex single mode cable is commonly used in long-haul network connections.

2.        Multi-mode

Multimode Fiber has a relatively wide core size of either 62.5 µm or 50 µm. The glass fiber has a slightly larger diameter to allow light to be sent through the fiber at different angles. 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 that there is more possibility for signal loss, reduction or interference.

Generally, multimode cable is used for communication over short to midrange distances, such as within a building or on a small campus. Typical multi-mode fiber links are suitable for distances under 2,000 feet.

Fiber-optic cabling is now being used in four types of industry:

•          Enterprise Networks: Fiber is used for backbone cabling applications and interconnecting infrastructure devices.
•          FTTH and Access Networks: Fiber-to-the-home (FTTH) is used to provide always-on broadband services to homes and small businesses. FTTH supports affordable high-speed Internet access, as well as telecommuting, telemedicine, and video on demand.
•          Long-Haul Networks: Service providers use long-haul terrestrial optical fiber networks to connect countries and cities. Networks typically range from a few dozen to a few thousand kilometers and use up to 10 Gb/s-based systems.
•          Submarine Networks: Special fiber cables are used to provide reliable high-speed, high-capacity solutions capable of or surviving in harsh undersea environments up to transoceanic distances.

Fiber Optic Transmission Technology

The basic fiber optic transmission system consists of three basic components:

•          Transmitter, which generates the light signal
•          fiber optic cable, which carries the light
•          receiver, which accepts the light signal that was transmitted

Advantages Of Fiber Optic Transmission

Optical fibers have largely replaced copper wire communications in core networks in the developed world, because of its advantages over electrical transmission. Here are the main advantages of fiber optic transmission.

1.        Extremely High Bandwidth & speed

The standard way to measure data transmission rates is via bandwidth. These days, it is measured in gigabits of data per second (Gbps), or even terabits per second (Tbps). Copper-based transmissions currently max out at 40 Gbps, whereas fiber optics can carry data at close to the speed of light. The volume of data that fiber optic cables transmit per unit time is far greater than any other cable-based data transmission medium. Hence, the speed of fiber optic system is faster.

2.        Longer Distance

In fiber optic transmission, optical cables are capable of providing low power loss, which enables signals can be transmitted to a longer distance than copper cables.

3.        Resistance to Electromagnetic Interference

In practical cable deployment, it’s inevitable to meet environments like power substations, heating, ventilating and other industrial sources of interference. However, fiber has a very low rate of bit error (10 EXP-13), as a result of fiber being so resistant to electromagnetic interference. Fiber optic transmission is virtually noise free.

4.        Low Security Risk

The growth of the fiber optic communication market is mainly driven by increasing awareness about data security concerns and use of the alternative raw material. Data or signals are transmitted via light in fiber optic transmission. Therefore there is no way to detect the data being transmitted by "listening in" to the electromagnetic energy "leaking" through the cable, which ensures the absolute security of information.

5.        Small Size

Fiber optic cable has a very small diameter. For instance, the cable diameter of a single om3 multimode fiber is about 2mm, which is smaller than that of coaxial copper cable. Small size saves more space in fiber optic transmission.

6.        Light Weight

Fiber optic cables are made of glass or plastic, and they are thinner than copper cables. These make them lighter and easy to install. Easy to Accommodate Increasing Bandwidth: with the use of fiber optic cable, new equipment can be added to existing cable infrastructure. Because optical cable can provide vastly expanded capacity over the originally laid cable. And WDM (wavelength division multiplexing) technology, including CWDM and DWDM, enables fiber cables the ability to accommodate more bandwidth.

7.        Flexibility

An optical fiber has greater tensile strength than copper or steel fibers of the same diameter. It is flexible, bends easily and resists most corrosive elements that attack copper cable. For example, copper wire transmission can generate sparks, causing shortages and even fire. Because fiber optical strands use light instead of electricity to carry signals, the chance of an electrical fire is eliminated. Moreover, they can be submerged in water- fiber optics are used in more at-risk environments like undersea cables.

This makes fiber optics an exceptionally safe form of wiring and one of the safest forms of data transmission.