Why needed cladding in optical fiber?

Why needed cladding in optical fiber? : Today we will talk on a topic which is considered to be the biggest change in the field of communication so far. The use of optical fiber in telecommunications is seen as a revolution. In this article we will discuss about the cladding used with optical fiber. What is cladding in optical fiber, why is cladding done and what does cladding work for?

Yes, we are talking about optical fiber which performs the transmission of signals with great speed. Its circulation is growing very fast. So let's try to know cladding what is the purpose of cladding in optical fiber. 

Facts about optical fiber

Those who have a little knowledge about optical fiber, will know how big a role of cladding in optical fiber. Before discussing about cladding in detail, I want to tell you some facts about optical fiber.

The optical fiber refers to the medium or technology through which we transmit data, voice, and images through the passage of light that goes through thin, transparent fibers. In Telecommunications, the technology of fiber optic has virtually replaced copper in long-distance telephone lines.

And right now it even works to link computers through the FTTH network. Fiber optic cable consists of varying number of glass fibers. This glass fiber core surrounds another glass layer which we call cladding. There is another layer which we call buffer tube which protects the cladding and there is a jacket layer which acts as the final protective layer of the individual strand. Look at the picture below for ease.

The basic medium of optical fiber is hair-thin-like fiber which is sometimes made of plastic but is mostly made of glass. The diameter of a typical glass optical fiber is 125 micrometer. This 125mirometer is the diameter of the cladding or outer reflecting layer. The diameter of the core or inner transmitting cylinder is about 8 micrometer. The degree of attenuation (signal loss) depends on the wavelength of the light and the composition of the fiber in a fixed distance.

Before 1966 optical fiber was not used for the communication sector since glass fiber for core / cladding was introduced in the 1950s, fiber was not being used for short length due to impurities being present. 

Then in 1966, two electrical engineers of England Charles Kao and George Hock ham, suggested the use of this fiber in telecommunication. After improvement in purity within two decade, silica glass fibers started to produce and the infrared light signals wire of travel capacity for 100 km had arrived. Signals could travel for even more distance with the help of repeater. In 2009, Kao received a Nobel prize for his work in physics. 

Plastic fibers that are usually made of polymethyl methacrylate, polystyrene or polycarbonate. Its production is low in price and they are more flexible than glass fibers but it impedes attenuation for light for use in very small links.

Cladding is component of Optical Fiber

To understand well about cladding, it has to understand the component used in it. Fiber optic has three basic components - in which cladding is also a component of optical fiber. 

1. Core (Inner Area) 8-10 micrometer - This is the area from which light is transmitted, the more the core, the more light can pass but also more dispersion of light occur. Core is generally made of glass.

2. Cladding (Middle part) 125 micrometer - Its function is to provide a minimum refractive index at the core so that the light wave can easily pass into the fiber. Generally Cladding is made of glass or plastic.

3. Coating or buffer (Outer Layer) 250 micrometer - This is a plastic layer that is used to strengthen the fiber. Generally cladding in optical fibers is coated with a layer of acrylate polymer or polyimide. This coating protects the fiber from any kind of damage.

Purpose of Cladding

Outer coating of core fiber is cladding, in fact light pulses or signals are launched into the core region. The surrounding the core fiber that is called cladding keeps the light traveling to the core and prevents it from leaking outside, and an outer coating, usually made of a polymer, this cladding is applied during the drawing process. 

The layer of glass around the core of an optical fiber. The lower index of refraction of the cladding as compared to the core reflects light completely internally within the core and remains in the core.

Last word

Friends, I hope that all of you have understood about cladding. You have received all the information about what is cladding, what is the purpose of using cladding and what does cladding work in an optical fiber? How did you like this article " Why needed cladding in optical fiber? ", please tell me by commenting, if the information is good then forward it to friends.