♥Understanding total internal reflection of light♥

Explaination of Total Internal Reflection

~If the angle of incidence in the glass is increased further,the light is not refracted any more,but it will be internally reflected.The phenomena is as known as total internal angle.
~The angle of incidence at this limit is called the critical angle,c
~The critical angle is defined as the angle of incidence in the denser medium when the angle of refraction in the less dense medium is 90°
Diagram of Total Internal Reflection and Critical Angle

θ1=θi=incidence angle

θ2=θr=refraction angle

~the green line shows the θi less than θc so the line refracted away from the normal

~the red line shows the θc is the angle of incidence in an optically denser medium when the angle of refraction is 90°

~the blue line shows the θi bigger θc so the ray passes from a denser medium to a less dense medium,this condition is known as total internal reflection

Phenomena of Total Internal Reflection

Mirage occurs due total internal reflection of light.When the sun high in the sky,the sands gets heated first and then the layers of air above it.The rays from the trees travel from an optical denser air layer to a rarer layer and hence bend away from the normal.This bending continues and a stage is reached where the angle of incidence becomes greater than tha critical angle and total internal reflection takes place.

Application of Total Internal Angle

~The cut of the diamond favors total internal reflection.Most rays entering the top of the diamond will internally reflect until they reach the top face of the diamond where they exit.This gives diamonds their bright sparkle.Notice in this animation that a ray entering the top does't exit the diamond until it reaches the top surface.

~A fiber optic is a glass "hair" which is so thin  that once light enters one end,it can never strike the inside walls at less than the critical angle.The light undergoes total internal reflection each time strikes the wall.Only when it reaches the other end is it allowed to exit the fiber.
~Fiber optic cables are used to carry telephone and computer communication.Advantages over electrical wired include:
1.Fiber optics can carry much more information in a much smaller cable.
2.No interference from electromagnet fields result in "clearer" connections.
3.No eletrical resistance.
4.No hazard of electrocution if cable breaks.