Optics Answers

Describe the structure and characteristics of a graded index multimode fibre suitable for optical fibre communication.

Draw the basic configuration of typical optical fibre communication.

What is a step - index fibre ? Obtain an expression for the angle of incidence beyond which light will get refracted into the cladding material. What will happen if the refractive index of the cladding is higher than that of the core ?

An ordinary source emits light at 103k. Show that in this case, spontaneous emission will dominate over stimulated emission.

For interference in thin films, obtain the condition of constructive and destructive
interference between reflected light waves.

The diffraction bands are of variable thickness,
whereas interference bands are equidistant'.
Discuss the validity of this statement with
reference to the diffraction pattern of a straight
edge.

Discuss how Michelson interferometer is used to determine the difference in the wavelengths of the doublet emitted by sodium.

In young's double slit arrangement, a thin
transparent sheet of thickness t and
refractive index u is introduced in the path of
one of the beams. Obtain the expression for
the distance through which each of the
maxima gets shifted.

e.m.waves are incident normally on an
interface separating two media of refractive
indices n1 and n2. Obtain expressions for
reflection and transmission coefficients.

Discuss the terms accommodation and
convergence in the context of image formed by
human eye.