- Geometrical loss:-
Due to bending of optical fibres there are 2 types of losses from macroscopic bending and microscopic bending. If the fibre be rounded as big circle of known radius of curvature, the loss may be less called macroscopic bending loss. For small bending of fibre the loss of energy in microscopic bending is larger. Some time the irregularities in the dimensions cause geometrical losses.
- Dispersion loss:-
In the transmission of light through optical fibres the pulse width varies due to dispersion of light through the core. The loss of intensity caused as result of dispersion of light is due to a)Material dispersion b)Waveguide dispersion c)Inter modal dispersion
a)Material dispersion:-
The refractive index of core causes the changes in the wavelength/frequency called material dispersion. If narrow pulse passes trough fibre, causes broadening of pulse width due to material property. It can be overcome by highly monochromatic source of light. The single mode fibre could reduce the material dispersion to maximum extent.
b)Waveguide dispersion:-
The optical fibre can be considered as circular wave guide where refractive index varies with modes of propagation with wavelength causes wave guide dispersion.
c)Intermodal dispersion:-
The optical power in the pulsed wave distribution over the mode of light through the fibre decreases during the propagation, these changes are known as intermodal dispersion.
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