Fibre Optics: Principal of Fiber

Define optical fibre. Describe its constructions?

Ans :Principal of Fiber Optics.
When a ray of light passes form a denser to rare
medium it bends away from the normal to the
interface. Now if we go on increasing the angle of
incidence then at a particular angle of incidence
then angle of refraction will become 90". when the
angle of incidence is made greater than x, the ray
does not refract but reflect into the same medium, It
is reflects into the same medium. It is called the
"'total internal reflection."
Light through optical fibre also passes due to the .
total internal refractive optical fibres are fine
stands of glass. The fibres have a core of pure
glass, which is surrounded by a different kind of
Light Signal 1
glass.
Light Signal 2
These days telecommunication optical fibre are
replacing metal cables for transmitting telephone calls in a better way. In this each
caller's voice is changed into a light signal


Use of fiber


Optical fibre enables doctors to look inside the human body.
As optical fibres are very thin so it can be easily passed into the body to get a required
picture.
Ineye surgery lightis obtained from fibre optic light guide.
Optical fibre can transmit thousand oftelephone calls,
L.V programmes can be transmitted by one or two flexible and thin hair like optical