20-06-2012, 02:06 PM
OPTICAL FIBRE COMMUNICATION SYSTEM
[attachment=24906]
Electronic spectrum:
The total electro magnetic spectrum that is starting from the subsonic frequency to cosmic rays. (10 paw 22 Hz) can be divided into 3 general bands.
1. Infrared:
Band of light wave length that art two Lang to be seen by the human eye.
2. Visible:
Band of light wavelength that the human eye will respond.
3. Ultraviolet:
Band of light wavelength that are too short to see by the human eye.
High frequency electromagnetic waves such as light can be measured in terms of ‘wave length’. Wavelength is the length of the wave that one cycle of an electromagnetic wave occupies in space. It is depends on the frequency of the wave and the velocity of light. Mathematically
Analog or digital interface:
At the receiver output is also an electrical Interface. If analog Modulation is used; the interface matches Impedances and signal level to the output circuitry. If digital Modulation is used; the interface must include a digital-to- Analog
Converter.
Single-mode-step-index fiber:
a single mode step index fiber has a central core that is sufficiently small. So that there is essentially only one path that light may take as it propagates down the cable.
Multi-mode-graded-index fiber:
A multi mode graded index fiber is characterized by a central care that has a refractive index that is non-uniform.
It is maximum at the center and decreases gradually towards the
Center edge. Light is propagated down this type of fiber through refraction. Light enters into the fiber at many different angles.
[attachment=24906]
Electronic spectrum:
The total electro magnetic spectrum that is starting from the subsonic frequency to cosmic rays. (10 paw 22 Hz) can be divided into 3 general bands.
1. Infrared:
Band of light wave length that art two Lang to be seen by the human eye.
2. Visible:
Band of light wavelength that the human eye will respond.
3. Ultraviolet:
Band of light wavelength that are too short to see by the human eye.
High frequency electromagnetic waves such as light can be measured in terms of ‘wave length’. Wavelength is the length of the wave that one cycle of an electromagnetic wave occupies in space. It is depends on the frequency of the wave and the velocity of light. Mathematically
Analog or digital interface:
At the receiver output is also an electrical Interface. If analog Modulation is used; the interface matches Impedances and signal level to the output circuitry. If digital Modulation is used; the interface must include a digital-to- Analog
Converter.
Single-mode-step-index fiber:
a single mode step index fiber has a central core that is sufficiently small. So that there is essentially only one path that light may take as it propagates down the cable.
Multi-mode-graded-index fiber:
A multi mode graded index fiber is characterized by a central care that has a refractive index that is non-uniform.
It is maximum at the center and decreases gradually towards the
Center edge. Light is propagated down this type of fiber through refraction. Light enters into the fiber at many different angles.