Fiber Optic | Fiber Optic Cable | Fiber Optic Communication | Fiber Optic Communication System Block Diagram | Advantages of Fiber Optic Communication

In today's digital age, where high-speed internet and efficient data transmission are paramount, fiber optic technology plays a vital role in connecting the world. Fiber optic refers to the transmission of data through thin strands of glass or plastic fibers, utilizing light signals. This revolutionary technology has revolutionized communication networks and is widely used in various industries. As on today the optical fiber optic communication is considered to be the best alternative for faster communication system. The fiber optic communication use light instead of current or voltage as the energy to carry the data.

Advantages of Fiber Optic Communication

Fiber optic technology offers numerous advantages over traditional copper cables. Firstly, fiber optic cables have a much higher bandwidth capacity, allowing for faster data transmission. This makes fiber optic ideal for applications that require high-speed internet, such as video streaming, online gaming, and cloud computing.

Secondly, fiber optic is immune to electromagnetic interference (EMI) and radio frequency interference (RFI). Unlike copper cables, which can suffer from signal degradation due to external factors, fiber optic cables provide a reliable and secure connection.

Additionally, fiber optic cables are lightweight and can be bundled together, allowing for efficient and cost-effective installation. They are also resistant to environmental factors such as moisture, temperature changes, and corrosion, making them highly durable.

1. Fast speed: It is possible to handle signals which turn on and off at gigabit per second rates.
2. Extremely wide bandwidth: This makes wide frequency band available for communication, increasing the capacity of communication network to handle data.
3. Noise immunity: The light signal is absolutely immune to electrical noise from any source.
4. Safe from theft of information: It is relatively hard to tap into the cable without being noticed, and the entire signal is confined within the fiber.
5. Immunity to hazardous atmosphere: Since there is no electrical energy involved, the fiber can be run in hazardous atmospheres where danger of explosion from sparks may exist.
Also the fiber itself is immune to many types of poisonous gases, chemicals and water history.

How Fiber Optic Works

At the heart of fiber optic technology lies the principle of total internal reflection. The fiber optic cable consists of a core, which carries the light signals, and a cladding layer that surrounds the core. The core has a higher refractive index than the cladding, which enables the light signals to bounce off the walls of the core and travel through the cable with minimal loss of signal strength.

To transmit data, a light source, such as a laser or an LED, is used to generate light pulses. These pulses of light travel through the fiber optic cable, bouncing off the walls until they reach the other end. At the receiving end, the light signals are converted back into electrical signals for further processing.

What is a Fiber Optic Communication?

It uses binary amplitude modulation so the light is switched on and off. This light is transmitted from source to the receiver through hair-thin strand or fiber of glass or plastic as a light pipe. If a light source is put at one end, any light that enters at one end of the fiber stays in that fiber and travels through the fiber to the other end. The light does not pass out of the walls of the fiber.

Fiber Optic Communication System Block Diagram

Fiber Optic | Fiber Optic Cable | Fiber Optic Communication

How it works?

It works because of the property called total internal reflection: If a light wave is traveling through a material with a high index of refraction compared to an adjacent material and it hits the interface between them at certain low angles, the light does not cross the boundary but completely reflects back. At the receiving end of the fiber, a light detector senses the light. Thus the fiber is used a communication medium and the energy used is the light energy.

The basic requirements:

  1. The light source should be small and reliable.
  2. The light source should be able to switch on and off at fast rates, for fast communication of data.
  3. The glass or plastic fiber has to be pure and smooth. Any impurity is equivalent of a wire resistance and would cause some of the light put into the fiber to be lost before it reached the other end.
  4. The source of light and the receiver that detects the light must be precisely lined up with the fiber. This particular problem has been overcome with the state of art connectors and the mechanical couplings.

Types of Fiber Optic Cables

There are various types of fiber optic cables available, each designed for specific applications. Single-mode fiber optic cables are used for long-distance transmission, providing high bandwidth and low signal attenuation. Multimode fiber optic cables, on the other hand, are suitable for shorter distances and offer cost-effective solutions for local area networks (LANs).

Other specialized fiber optic cables include armored cables for harsh environments, plenum-rated cables for building infrastructure, and aerial cables for above-ground installations. The choice of fiber optic cable depends on factors such as distance, bandwidth requirements, and environmental conditions.

Fiber Optics Internal Structure

Fiber Optics is sending signals down hair-thin strands of glass or plastic fiber. The light is “guided” down the center of the fiber called the “Core”. The core is surrounded by a optical material called the “cladding” that traps the light in the core using an optical technique called “total internal reflection.”
Fiber Optic Communication
The cladding and core are usually made of ultra-pure glass. The fiber is coated with a protective plastic covering called the “primary buffer coating” that protects it from moisture and other damage. Extra protection is provided by the “cable” which has the fibers and strength members inside an outer covering called a “jacket”.

Fiber-optic Cable Propagation Modes

Fiber-optic cable has two propagation modes: single mode & multimode. They perform differently with respect to both attenuation and time dispersion. The single-mode fiber-optic cable provides much better performance with lower attenuation. 

Single Mode Fiber Optic Cable

Fiber Optic | Fiber Optic Cable | Fiber Optic Communication | Fiber Optic Communication System Block Diagram | Advantages of Fiber Optic Communication
Single Mode fiber optic cable has a small diametric core that allows only one mode of light to propagate. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and creating the ability for the signal to travel faster, further. This application is typically used in long distance, higher bandwidth runs by Telcos, CATV companies, and Colleges and Universities.
Single Mode fiber is usually 9/125 in construction i.e core to cladding diameter ratio is 9 microns to 125 microns.

Multimode Fiber Optic Cable

Fiber Optic | Fiber Optic Cable | Fiber Optic Communication | Fiber Optic Communication System Block Diagram | Advantages of Fiber Optic Communication
Multimode fiber optic cable has a large diametral core that allows multiple modes of light to propagate. Because of this, the number of light reflections created as the light passes through the core increases, creating the ability for more data to pass through at a given time. Because of the high dispersion and attenuation rate with this type of fiber, the quality of the signal is reduced over long distances. This application is typically used for short distance, data and audio/video applications in LANs. RF broadband signals, such as what cable companies commonly use, cannot be transmitted over multimode fiber.
Multimode fiber is usually 50/125 and 62.5/125 in construction i.e. core to cladding diameter ratio is 50 microns to 125 microns and 62.5 microns to 125 microns.

Challenges and Limitations of Fiber Optic

Despite its numerous advantages, fiber optic technology has some challenges and limitations. One of the main challenges is the high cost associated with deploying fiber optic networks, especially in remote or rural areas. The installation and maintenance expenses can be significant, requiring careful planning and investment.

1) Termination of fiber: Unlike wire, which can be stripped of insulation easily, then mechanically connected and soldered if required, fibers have to be cut very carefully so that the cut end is smooth and straight. 

Special tools are needed for this. If the fiber has to be spliced into another fiber for longer length, this involves carefully cutting and polishing the cut ends and joining them in a special fiting, often with a special optically clear glue.

The ends of the two fibers must be in perfectly straight-line alignment, unlike copper wires which can be simply stripped, twisted and crimped or soldered together.

2) Less suitability for multiple users on the same line: For mechanical and optical reasons, at present there is no satisfactory way to have a party line whose users can be attached to or removed from the line easily.

Because of this reason the fiber optics are used mainly for point to point communications, in which data is going from one point to another, with no new users picked up or dropped of along the way.

3) Another limitation is the fragility of fiber optic cables. They can be easily damaged if not handled with care during installation or maintenance activities. External factors such as construction work or natural disasters can also pose a risk to the integrity of fiber optic networks.


Fiber Type:

There are different types of fibers used in fiber optic cables, such as single-mode and multi-mode. Single-mode fibers have a smaller core diameter and are used for long-distance communication, while multi-mode fibers have a larger core diameter and are used for shorter distances.

Core Diameter:

The core diameter of a fiber optic cable determines the amount of light that can be transmitted through it. The core diameter can range from 8 to 62.5 microns for multi-mode fibers and from 8 to 10 microns for single-mode fibers.

Cladding Diameter:

The cladding diameter is the diameter of the protective layer that surrounds the core of the fiber. It is typically 125 microns for single-mode fibers and 125 or 250 microns for multi-mode fibers.

Numerical Aperture:

The numerical aperture is a measure of the acceptance angle of the fiber, which is the maximum angle at which light can enter the fiber and still be transmitted. It is typically higher for multi-mode fibers than for single-mode fibers.


Attenuation is the loss of signal strength as the light travels through the fiber. It is measured in decibels per kilometer (dB/km) and is typically lower for single-mode fibers than for multi-mode fibers.


Bandwidth is the amount of data that can be transmitted through the fiber optic cable per unit time. It is typically higher for multi-mode fibers than for single-mode fibers.

Operating Temperature:

Fiber optic cables have a specified operating temperature range within which they can function properly. The operating temperature range is usually between -40°C to +85°C.

Fiber Optic Splicing

Fiber optic splicing is the process of joining two fiber optic cables together to form a continuous optical path. There are two types of splicing: fusion splicing and mechanical splicing.

Fusion Splicing: 

Fusion splicing involves melting the two fiber ends together using an electric arc or a laser. The fibers are aligned and fused together by heating the ends until they melt and then letting them cool down. This creates a permanent, low-loss joint that is almost as strong as the fiber itself.

Mechanical Splicing: 

Mechanical splicing involves aligning the two fiber ends and holding them in place with a mechanical splice device. The device typically uses a precision alignment mechanism to ensure the fibers are aligned correctly. An adhesive or a mechanical crimp is then used to hold the fibers together.

The advantages of fusion splicing over mechanical splicing include lower insertion loss, higher tensile strength, and better environmental stability. However, fusion splicing requires specialized equipment and trained technicians, which can make it more expensive.

Mechanical splicing is quicker and easier than fusion splicing, and it does not require specialized equipment. However, it has higher insertion loss and lower tensile strength than fusion splicing.

Both fusion and mechanical splicing are commonly used in fiber optic cable installations, and the choice of splicing method depends on the specific application, budget, and technical requirements.

Applications of Fiber Optic

Fiber optic technology finds applications in various industries. In the telecommunications sector, fiber optic is the backbone of high-speed internet connections, enabling seamless data transmission across long distances. It is also used for interconnecting data centers, ensuring fast and reliable communication between servers.

In the healthcare industry, fiber optic plays a crucial role in medical imaging and diagnostic equipment. It enables the transmission of high-resolution images and real-time data, enhancing the accuracy and efficiency of medical procedures.

Furthermore, fiber optic is widely used in the aerospace and defense sectors, where secure and reliable communication is essential. It is also utilized in industrial automation, oil and gas exploration, and transportation systems, among other fields.

Future of Fiber Optic Technology

The future of fiber optic technology looks promising, with ongoing advancements and innovations. Researchers are working on developing even faster fiber optic networks, utilizing technologies such as space-division multiplexing and wavelength-division multiplexing.

The advent of 5G networks and the increasing demand for high-speed internet will further drive the adoption of fiber optic technology. Additionally, the Internet of Things (IoT) and smart city initiatives will rely heavily on fiber optic infrastructure for seamless connectivity and efficient data transmission.


In conclusion, fiber optic technology has revolutionized communication networks, providing high-speed and reliable data transmission. Its advantages over traditional copper cables, such as higher bandwidth, immunity to interference, and durability, make it the preferred choice for various applications. As technology continues to advance, fiber optic will play a crucial role in shaping the future of connectivity and enabling the digital transformation of industries.

FAQs (Frequently Asked Questions)

Q: Can fiber optic cables be used for both internet and telephone connections?

A: Yes, fiber optic cables can transmit both internet and telephone signals efficiently.

Q: How fast is fiber optic compared to traditional broadband?

A: Fiber optic can provide much higher speeds, with some networks offering gigabit or even terabit connections.

Q: Are fiber optic cables immune to lightning strikes?

A: While fiber optic cables are not affected by lightning directly, they can still be damaged if the electrical surge reaches the equipment connected to them.

Q: Can fiber optic cables be upgraded to higher speeds in the future?

A: Yes, fiber optic networks can be upgraded to higher speeds by replacing the active equipment while retaining the existing cable infrastructure.

Q: Is fiber optic available in rural areas?

A: Fiber optic deployment in rural areas depends on factors such as demand, feasibility, and infrastructure development plans.

No comments

Powered by Blogger.