Optical Fiber Communications Case Study 2022

Electronics
Title - Optical fibre communications

Abstract: - Optical fibre cables are used for imaging and lighting as well as sensors
to monitor a huge array of variables. Optical fibre cables are also used for
development and research and testing across all the industries. In this study, we
will research on the types of cables used in the application of broadcast. Multi-
channel audio and H.D. video in the broadcasting market, higher demands are
being put on data transmission systems.
1.Introduction:-
Today Cable television network system plays a vital role in the entertainment
service industry which provides the broadcast television and on-demand video
service at high speeds. Coaxial cable is used to transmit the analogue signal. Now a
day’s cable television companies found that for transmitting the signal at different
location fibre is the right choice. With the help of the optical fibre, each location of
the customer is connected to an isolated terminal and tuner is connected to each
customers T.V. set. The remote terminal is used for the channel selection through
the fibre at the customer’s location. These applications built the better relationship
of cables companies with the customer’s. This leads to an increase the company
revenue by providing them to return path from which customers can use for the
internet, cable T.V. signals and telephone connection [3].
Fibre optic technology has ability to deliver high-bandwidth, and low signal
loss data streams and is ideally suited to manage these needs. Fibre Savvy offers a
range of fibre optic broadcast products that are specifically designed to withstand
the challenges for real-time transmission of high definition broadcast signals.
Optical fibre cables have the potential to transmit the High Definition (H.D.)
Television signals with higher speed and bandwidth. Cost of the optical fibre is less
as compared to copper wires. Many Broadcasting companies use the optical fibre
wiring for the CATV, HDTV, video on demand and other applications.
2. Theory of Operation
To transmit the data in gigabits and more than gigabits fibre optics are used. This
communication is used to send the video, voice data and telemetry over the long-
distance via the computer network. It used the light wave technology to transfer the
signal over fibre and converts the electronic signal into the light. This

communication system has many characteristics such as smaller diameter, large
bandwidth, low attenuation, long-distance transmission signals and transmission
security.
2.1Operation of the system or component:-
Transmission of signals entirely depends upon the processing of the electrical signal
in the cable. Optical fibre transmits the signals in the form of light from one terminal
to another terminal. The circuitry of the optical fibre is consists of the transmitter,
receiver, light source and detector devices.
Figure 1:- Block Diagram of O.F.C. (Optical Fiber Communication) [7]
2.2Operation:-
In the form of electrical signals input data is given to the transmitter of the circuit
then it converts it into the light signals with the help of the light source (L.E.D. or
LASER). Amplitude, phase and the frequency of the source must be stable and free
from the fluctuation for the efficient transmission. From the source, the light beam
is passing through the optical fibre to the endpoint or destination circuitry, and
information is transmitted back with the help of the receiver circuit. The Receiver
circuit contains a photo-detector with the appropriate channel. The photo-detector
is accomplished of measuring frequency, phase and magnitude of the optical field.
For this type of broadcast, communication uses the wavelength near to the infrared
region, and it is just above the visible region.
3.System Solution:-

Issues arise in the fibres are Optical loss measurement, optical power
measurement, choose the fibre according to distance (Single-mode or multimode
fibre).
3.1Optical Power Design based on the consideration:-
The design of Optical fibre is based on the multiplexing and modulation technique
used for the specific application. One design consideration is 'Power budget'. It
relates to the availability of power at the receiver. It also depends upon the
bandwidth, rise time BER (Bit Error Rate), data rate and effect of noise on system
Bandwidth and cost.
The essential elements of the optical fibre communication systems are low loss
optical fibre, compact light source and photo-detector. Low loss optical fibre also is
called as cylindrical dielectric waveguide it is consists of the low loss material. The
cable of the fibre optics is consists of high-quality plastic or glass (si). The diameter
of the optical fibre cable lies in the range of the 0.25 to 0.5mm. It is slightly thicker
than a human hair.
Figure 2:- Shows the Fiber Optical Cable [3]
A cable of optical fibre mainly consists of four component name as cladding, core,
buffer and jackets. Due to Total Internal Reflection core reflects the light to the
cladding boundary. Cladding is the outer layer of the fibre and protects the core of
the fibre. Its primary function is that it redirects the light back to the core when light
enters the core to cladding. Buffer protects the optic fibre from the damage and
thousands of optical fibres arranged in the bundle of hundreds of optical cables.