Presentation of lateral shift

The presentaion is about lateral shift and its variance with angle of incidence

1. Lateral shift and its variance with angle of incidence

2. Refraction of light The phenomenon of bending of light as it moves from one medium to another is called refraction of light. The laws of refraction are: The incident ray, refracted ray and normal at the point of incidence all lie at the same point. The ratio of sine of angle of incidence to the sine of angle of refraction is always constant. This constant is known as refractive index. i.e. µ = This is often known as Snell's law  

3. Lateral shift The perpendicular distance between the original direction of incident ray and emergent ray and emergent ray is lateral shift. Lets consider a ray of light AO is incident on air-glass interface making angle of incidence AON’= i which refracted in glass medium making angle of refraction N’OB and finally emerges out of the glass along BE making angle of emergence M’BE=e If incident angle AO is produced, then it will be parallel to the emergent Ray BE. A perpendicular drawn from the point of emergent to the original direction of incident ray measures the lateral shift i.e. BP=d is the lateral shift.  

4. From figure, BOP= i – r In triangle BOP, -------(1) Again, in triangle N’OB, or, OB= ------------(2) From equation 1 and 2, we get or, BP = If ON’=t be the thickness of glass slab, then d= This is the required expression for lateral shift.  

5. Cases: If i =0 then, r=0 So, d=0 2) If i =90 then , d=t Thus, when the angle of incidence is 90 , lateral shift is maximum and is equal to the thickness of slab. If a graph is plotted between angle of incidence with lateral shift it is obtained as shown below. The graph shows that, lateral shift increases in angle of incidence and becomes maximum when the angle of incidence is 90