Optical Fiber –Types, Advantages, Disadvantages & Applications

In this article, we will discuss optical fiber, its definition, construction, working, advantages, disadvantages, and applications. So, let’s get started with the basic introduction of optical fiber.

What is Optical Fiber?

Optical fiber is a type of medium used for data communication or data transmission with the help of light pulses. Optical fiber is a hair-thin flexible stand made up of glass. It is capable of transmitting optical signals from one point to another over long distances.

These days, optical fibers are widely used in high-speed digital data transmission in Internet communication. They are more efficient than ordinary copper cables, as the light signals are not affected by electromagnetic interference. Optical fiber works on the principle of total internal reflection of light. Therefore, in the case of optical fiber, no light can leave the optical fiber boundary once it entered the fiber core.

Construction of Optical Fiber

An optical fiber cable typically consists of three major parts namely, core, cladding, and outer jacket.

The core of the optical fiber is a thin glass or plastic strand have a cylindrical shape through which light pulses travel from one end to another. The diameter of the core of the optical fiber typically ranges from 4 microns to 10 microns.

optical fiber

The layer which covers or surrounds the core of the optical fiber is referred to as cladding. The cladding of the fiber cable is made up of a different material that is used for making the core. Generally, the cladding material is chosen such that it has a refractive index that is lower than that of the core material. This allows the light to travel along the fiber cable.

The higher refractive index of the cladding as compared to the core totally reflects the light back into the core, when it reaches the boundary between the core and cladding.

Finally, there is an outermost layer that serves as a protective cover for the fiber cable. This layer is commonly called an outer jacket. It is made up of a high-grade polymer material that can handle environmental impacts.

Working of Optical Fiber

The working of the optical fiber is very simple, i.e. it just guides the light or optical signals along the length of the fiber core by using total internal reflection.

As we discussed above, the cladding layer of the optical fiber is made up of relatively lower refractive index material, while the core is of higher refractive index material. Thus, when an optical signal enters the core of the fiber, it is guided through the core by repeated total internal reflection by the boundary between the core and cladding.

Optical fiber transmits data signals in the form of light. Therefore, at the sending end, there is a light generator is used to convert digital signals into optical signals, and at the receiving end, an optical-to-electric converter is used to recover the original signal.

This way an optical fiber works to transmit signals from one point to another in a network.

Types of Optical Fiber

Based on modes of transmission, the fiber cable is classified into the following two types:

(1). Single-Mode Optical Fiber (SMOF):

A type of fiber cable that has only one path to propagate the light ray is called a single-mode optical fiber. Single-mode fiber cable has a relatively smaller size of the core, typically around 9 microns. As there is only one path for the transmission of optical signals, hence it allows long-distance transmission with low losses. However, single-mode fiber cable is comparatively expensive to manufacture and install.

(2). Multimode Optical Fiber (MMOF):

A type of fiber cable that has multiple paths inside the core for the propagation of light signals is called a multimode optical fiber. Multimode fiber cable has a core of larger diameter than single-mode fiber cable, typically 50 microns to 62 microns.

Hence, the multimode fiber cable can transmit more light at once. However, this type of optical fiber is better suited for a short distances and lower bandwidth data transmission.

Advantages of Optical Fiber

The following are the major advantages of fiber cable.

1. Stronger Security

It does not radiate the signal outside the fiber and difficult to tap the connection. In the case of the copper cable system, the equipment needs to be installed at various locations throughout the facility. However, the hardware of fiber can be installed in one central location. Thus, it provides stronger security.

2. Greater Flexibility

The productivity of a business gets adversely affected when communication is slow and connectivity is not reliable. Any unplanned downtime affects the productivity of the business.

When compared to copper cables, fiber optic cables are lighter in weight and thinner. They can withstand more pull forces than copper and thus, they are less apt to damage and breakage. The fiber cables are more flexible and can be easily bent and they have excellent corrosion resistance.

One of the very important features of fiber cables is that they do not conduct electricity and therefore these cables are fully-resistant to electromagnetic interference, lightning, or radio signals. On the other hand, copper cables are vulnerable to induced voltage, surge voltage, and lightning voltage.

Inclement weather conditions can interfere with or stop data transmission in the case of copper cables. However, Fiber cables do not get affected under such conditions.

3. Faster Speed

Simultaneous work like uploading videos, files and making phone calls, and downloading are the need of the day for the efficient running of the business. All the jobs need to be done at a fast speed. A slow internet connection affects the productivity of the business. The fiber cable system has a very high speed of data transmission because of its higher bandwidth.

Fiber cable networks are extremely faster, even faster than the highest-speed copper internet connections.

4. Longer Transmission Distances

We can achieve higher bandwidths over greater transmission distances if there is a low power loss in the cable. The copper cable has a high power loss, therefore it is not suitable for longer data transmission. On the other hand, fiber cables have a low power loss and are best suitable for data transmission over a longer distance. If we compare fiber with copper cable, the fiber cables can reach 10’s of kilometers in distance, whereas copper cables can reach 100-meter distance.

5. Higher bandwidth

In comparison to metal cables, Fiber cables have much greater bandwidth. The prominent advantage of fiber cable is that Information can be transmitted per unit time of fiber over other transmission media. More bandwidth allows simultaneous data transmission over a single transmission media.

If you are facing problems like multicast video breaking down, CCTV images pixelating/shearing, and difficulties in accessing cloud applications, you must upgrade your network to fiber optic connectivity.

6. Superior Carrying Capacity

The fibers are very thin and more of them can fit into a given-diameter cable than copper wires.

7. Improved Latency

Fiber optic networks eradicate many latency issues on the cable network such as downloading or uploading a video or consuming high-definition content. Lowering your latency improves the voice quality for VOIP users, the speed of the uploading and downloading of huge data files, and improved collaboration between employees.

8. Thin & Lightweight

They are much thinner and lighter than copper wires. This allows them to be drawn into smaller diameters. Thus, they are more suitable for places where space is restricted.

Disadvantages of Optical Fiber

The following are some major disadvantages of fiber cable.

1. Production & Installation Cost

Fiber cables are costlier than copper cables. Also, the cost of installation of fiber cables is more expensive because special test equipment is required.

2. Splicing Difficulties

Splicing is done when adding a new fiber optic network or expanding an existing network. The slicing is a very specific and specialized process and it needs expertise for the proper slicing of fiber cables. If the fiber cables are not connected properly, it will cause a signal loss.

3. Installation & Construction Risk

Fiber cables are very compact and small and thus, these cables are more vulnerable to damage during installation construction/renovation activities. Therefore, it is very essential to consider restoration, backup, and survivability.

4. Fragility

Fiber cables are made of fragile materials like glass. Therefore, fiber cables are more delicate than copper cabling. The fiber breaks If you bend them too much.

5. More Complex

Optical fiber has a more complex transmission system than copper cables, as it requires more equipment at sending and receiving ends.

Applications of Optical Fiber

These days, optical fiber is extensively used in several applications. Some common applications of fiber cable are listed below:

1. Telecommunication for data transmission

Fiber cables are widely used for optical fiber communication systems because they can be used for both transmission as well as for reception. By using various network applications, its speed, and accuracy can be improved. It provides high-speed connectivity.

2. Broadcasting

Optical fibers are used for delivering high-speed and high-bandwidth HDTV signals. It can be connected to HDTV, CATV, and other services. Fiber cables are less costlier than copper cables.

3. Defense

Optical fiber cables are widely used for those applications where high-level data security is a must. They are used in military, aerospace, and hydrophones for SONAR and seismic applications.

4. Medical Industry

Optical fiber is very thin and it can be inserted in lesser space areas. In the medical field, they are used to observe the interior body parts by entering hollow places in the body. Fiber cables are used for Surgical lasers, endoscope lasers, microscope lasers, and biomedical lasers.

5. Decoration and Lighting

Optical fiber cables are used for decoration of  Christmas decorations and trees

6. Mechanical Inspection

Optical fiber cables are used to inspect the parts or components installed in confined hard to-reach places. Plumbers also use fiber cables for the inspection of pipes.

7. Industrial Applications

These cables are used for taking the picture of hard-to-reach places like they are used for safety measures and lighting purposes in automobiles both in the interior and exterior. They are best suited for airbags and traction control applications. They are also widely used for research and testing purposes in industries.


In conclusion, optical fiber is a reliable and efficient medium for data transmission over long distances. It provides high-speed data communication that makes it suitable for a variety of applications like internet connectivity, telecommunication, medical imaging, etc.

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