This document discusses total internal reflection and some of its applications. Total internal reflection occurs when light travels from an optically denser medium to a less dense medium at an angle greater than the critical angle, causing the entire light ray to be reflected back into the denser medium. This phenomenon is used to create mirages by light rays curving downward in air of varying densities near the ground. Optical fibers are also able to transmit light along their length due to total internal reflection of light off the fiber walls. Cut diamonds are designed to take advantage of total internal reflection to reflect light internally and appear brilliant.

1. TOTAL INTERNAL REFLECTION
&
ITS APPLICATIONS
Presented by
Chithra V M
Physical Science
GCTE Thycaud

2. Optical density
 Ability of a medium to refract light
 Two types of medium-rarer medium and denser medium
 Rarer medium has lower refractive index
 Denser medium has higher refractive index
 Speed of light is higher in rarer medium than in denser
medium

3. Bending of light takes place when light passes obliquely from one
transparent medium to another.

4. • When light ray enters from a denser medium to a rarer medium it
bends away from the normal

5.  As angle of incidence (i) increases so does the angle of refraction
 At a particular angle of incidence the angle of reflection becomes 900
 Refracted ray grazes the surface at the interface between the two media
The angle of incidence for which angle of refraction becomes 900
CRITICAL ANGLE

6. • When angle of incidence becomes greater than critical angle the
incident ray is totally reflected

7. Total internal reflection
When a ray of light travels from denser medium to rarer medium ,if
the angle of incidence is greater than the critical angle the entire ray
is reflected into the same medium by obeying the laws of reflection .
Conditions for total internal
reflection
 Light must travel from denser medium to rarer medium
 The angle of incidence must be greater than the critical angle

9. Mirage
 The optical illusion due to total
internal reflection
 On sunny days the air near the
ground is cooler than that
higher up
 The light rays curve
downward, producing a
superior image

10. Optical fiber
 Thin hair like structure
 Light enters one end of the wall of the fiber
strikes at less than critical angle
 Light undergoes repeated total internal reflection
 Light emerges through the other end of fiber

11. Diamond
 The critical angle of diamond is very small
 The cut of diamond favors total internal
reflection
 Rays entering the top of diamond reflects
internally

12. THANK YOU