Total Internal Reflection (TIR ) from STAO’s ScienceWorks Gr. 10 Optics Survival CD Lesson 13

Total Internal Reflection (TIR) is also used in Fibre Optics. When the incident ray enters the more optically dense material, it……

When the incident ray enters the more optically dense material, it bends toward the normal as usual. Total Internal Reflection (TIR) and Fibre Optics

When the ray moves from the more optically dense material to air, the angle of incidence is greater than the Critical Angle (  c ) and the light is totally reflected. Total Internal Reflection (TIR) and Fibre Optics

This continues as the light ray travels through the fibre. The angle of incidence is greater than the Critical Angle (  c ) and the light is totally reflected. Total Internal Reflection (TIR) and Fibre Optics

This continues as the light ray travels through the fibre. The angle of incidence is greater than the Critical Angle (  c ) and the light is totally reflected.

Total Internal Reflection (TIR) and Fibre Optics This continues as the light ray travels through the fibre. The angle of incidence is greater than the Critical Angle (  c ) and the light is totally reflected.

Notice that when the fibre is bent sharply, the angle of incidence is close to the Critical Angle (  c ) and may partly refract out of the fibre. Total Internal Reflection (TIR) and Fibre Optics

Notice that when the fibre is bent sharply, the angle of incidence is close to the Critical Angle (  c ) and may partly refract out of the fibre.

and the ray refracts out of the fibre bending away from the normal. As the ray approaches the last surface, the angle of incidence is less than the Critical Angle (  c )

Fibre Optics (light) can carry much more information (band width) than traditional copper wire.

16)Why do cut diamonds sparkle so much?

Recall that diamond has a high index of refraction. As light enters diamond……

Recall that diamond has a high index of refraction. As light enters diamond, it bends more than when going into other materials.

It also results in diamond having a small critical angle. This increases the likelihood of Total Internal Reflection (TIR) occurring in the diamond.

The carefully calculated shape of cut diamonds also increases the likelihood of any light entering to be reflected back out the top.

The carefully calculated shape of cut diamonds also increases the likelihood of any light entering to be reflected out the top.

Also recall that the high index of refraction of diamond causes large dispersion or separation of colours. The colours are even more widely separated due to multiple internal reflections.