Optical Communication



OPTICAL COMMUNICATION
is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. Let we learn the optical communication one by one chapter.

Introduction :
1. Optical sources :

Characteristics of light sources for communication :

It must be possible to operate the device continuously at a variety of temperatures for many years.

Properties of light :

Light is electromagnetic radiation that has wave properties. Light waves can travel in a straight line. Read more

2. Optical fibers : Types, Materials and Fabrications :

Step index fiber :
The step index fiber is fiber is a cylindrical wave guide core with inner core has a uniform refractive index of n1 and the core is surrounded by outer cladding with uniform refractive index of n2.

Graded index fiber :
The graded index fiber has a core made from many layer of glass. In the graded index fiber the refractive index is not uniform within the core. Read more 

3. Photo detector and photo diode :

Photo detector :
The photo detector is also called optical receiver. It is convert the variation in optical power into a corresponding variation in the electric current. 

Photo diode :
Photo diode in order to convert the modulated electrical light back into an electrical signal, It is one type of light detector. Read more

4. Optical amplifier :

Optical amplifier is nothing but a laser without feedback. Optical amplification depends on frequency of incident signal and local beam intensity. 

Semiconductor optical amplifier :

Optical amplifier is nothing but a laser diode without feedback. Which introduce in 1990. It is mainly used inline optical amplifier. Semiconductor optical amplifier is a laser diode without end mirror. Read more

5. Advanced optical fiber system

What is WDM ?
The scheme of combining a number of wavelength over a single fiber called wavelength division multiplexing.

What is SONET ?
It is synchronous system  which provide simple network infrastructure and more flexible network. SONET is very similar to SDH. SONET is the standard used in the US where SDH is the standard used. Read more