21-06-2013, 02:33 PM
OPTICAL FIBERS
OPTICAL FIBERS[.ppt (Size: 534.5 KB / Downloads: 37)
Introduction:
Optical fibers are glass or plastic which looks like a thin as a human hair designed to guide light waves along their length.
it works on the principle of total internal reflection
Parts of Optical Fiber
Core – thin glass center of the fiber where light travels.
Cladding – outer optical material surrounding the core.
Buffer Coating – plastic
coating that protects
the fiber.
Total Internal Reflection
The angle of the light is always greater than the critical angle.
Cladding does not absorb any light from the core.
The extent that the signal degrades depends upon the purity of the glass and the wavelength of the transmitted light.
Single-mode fibers
Single-mode fibers are used to transmit one signal per fiber (used in telephone and cable TV). They have small core (9 microns in diameter) and transmit infra-red light from laser.
Applications
Carry plain old telephone service (POTS)
For transmission of data
Transmitting broadband signals
In the biomedical industry
Non-Communication Applications (sensors etc…)