Optical Fibre : A boon for Today's Technology

Have you ever wondered how your internet data travels to you through various mediums. Can you imagine a wire thinner than the diameter of your hair can perform total internal reflection and deliver your data on your network in appropriate form.

Let’s know how this works:

Optical fiber or Fiber Optics is the  medium and the technology associated with the transmission of information as light pulses along a glass or plastic strand or fiber. Fiber optics is used long-distance and high-performance data networking.

But the question is how this light tavels through wire ?

Now let me ask a question that have you ever heared about total internal reflections?

For those who don’t know let me explain first :

When the light is incident on a reflecting surface , it reflects in a certain direction. The phenomenon of Total Internal Reflection occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle. In general, total internal reflection takes place at the boundary between two transparent media when a ray of light in a medium of higher index of refraction approaches the other medium at an angle of incidence greater than the critical angle. For a water-air surface the critical angle is 48.5°. Because indices of refraction depend on wavelength, the critical angle (and hence the angle of total internal reflection) will vary slightly with wavelength and, therefore, with colour. At all angles less than the critical angle, both refraction and reflection occur in varying proportions.

Now let us Talk about how this happens in Optical Fibre :-

When light passes from a medium with one index of refraction (m1) to another medium with a lower index of refraction (m2), it bends or refracts away from an imaginary line perpendicular to the surface (normal line). As the angle of the beam through m1 becomes greater with respect to the normal line, the refracted light through m2 bends further away from the line.

At one particular angle (critical angle), the refracted light will not go into m2, but instead will travel along the surface between the two media

If the beam through m1 is greater than the critical angle, then the refracted beam will be reflected entirely back into m1 (total internal reflection), even though m2 may be transparent!

In an optical fiber, the light travels through the core (m1, high index of refraction) by constantly reflecting from the cladding (m2, lower index of refraction) because the angle of the light is always greater than the critical angle. Light reflects from the cladding no matter what angle the fiber itself gets bent at, even if it's a full circle!

Because the cladding does not absorb any light from the core, the light wave can travel great distances. However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends upon the purity of the glass and the wavelength of the transmitted light.

What are the Practical uses of Optical Fibre?    

optic cables are cables that contain several thousand optical fibers in a protective, insulated jacket. The optical fibers are very thin strands of pure glass, which transmit information in the form of light. Fiber optic cables have revolutionized the world of network communication ever since their inception nearly four decades ago. Today, these cables have almost obliterated traditional methods of networking, which use metallic wires by providing higher bandwidth and transmitting data over greater distances. Some of the most popular uses of fiber optic cables are listed below.

a. Internet

Fiber optic cables transmit large amounts of data at very high speeds. This technology is therefore widely used in internet cables. As compared to traditional copper wires, fiber optic cables are less bulky, lighter, more flexible, and carry more data.

b. Cable Television

The use of fiber optic cables in the transmission of cable signals has grown explosively over the years. These cables are ideal for transmitting signals for high definition televisions because they have greater bandwidth and speed. Also, fiber optic cables are cheaper as compared to the same quantity of copper wire.

c. Telephone

Calling telephones within or outside the country has never been so easy. With the use of fiber optic communication, you can connect faster and have clear conversations without any lag on either side.

d. Computer Networking

Networking between computers in a single building or across nearby structures is made easier and faster with the use of fiber optic cables. Users can see a marked decrease in the time it takes to transfer files and information across networks.

e. Surgery and Dentistry

Fiber optic cables are widely used in the fields of medicine and research. Optical communication is an important part of non-intrusive surgical methods, popularly known as endoscopy. In such applications, a minute, bright light is used to light up the surgery area within the body, making it possible to reduce the number and size of incisions made. Fiber optics are also used in microscopy and biomedical research.

f. Lighting and Decorations

The use of fiber optics in the area of decorative illumination has also grown over the years. Fiber optic cables provide an easy, economical and attractive solution to lighting projects. As a result, they are widely used in lighting decorations and illuminated Christmas trees.

g. Mechanical Inspections

Fiber optic cables are widely used in the inspection of hard-to-reach places. Some such applications are on-site inspections for engineers and also inspection of pipes for plumbers.

h. Military and Space Applications

With the high level of data security required in military and aerospace applications, fiber optic cables offer the ideal solution for data transmission in these areas.

i. Automotive Industry

Fiber optic cables play an important role in the lighting and safety features of present-day automobiles. They are widely used in lighting, both in the interior and exterior of vehicles. Because of its ability to conserve space and provide superior lighting, fiber optics are used in more vehicles every day. Also, fiber optic cables can transmit signals between different parts of the vehicle at lightning speed. This makes them invaluable in the use of safety applications such as traction control and airbags.

 

Therefore Optical Fibre proved to be very useful in every technical field.

Stay Tuned J

Thank You !