An optical fiber works on the principle of ......

$A$ light ray falls on a square glass slab as shown in the diagram. The index of refraction of the glass,if total internal reflection is to occur at the vertical face,is equal to

What is the maximum acceptance angle at the entrance surface of an optical fiber,if $n_1$ and $n_2$ are the refractive indices of the core and cladding,respectively?

The critical angle for a denser-rarer interface is $45^{\circ}$. The speed of light in the rarer medium is $3 \times 10^8 \, m/s$. The speed of light in the denser medium is:

$A$ beam of light consisting of red,green and blue colours is incident on a right-angled prism. The refractive index of the material of the prism for the above red,green and blue wavelengths are $1.39, 1.44$ and $1.47$ respectively.
The prism will

Show that for a material with refractive index $\mu \geqslant \sqrt{2}$,light incident at any angle shall be guided along a length perpendicular to the incident face.