Refraction of Light

Refraction of Light
Refraction is the phenomenon of change in direction of light when it travels from a rarer medium to a dnser medium and vice versa.

Snell's Law
μ = sin i / cos r

Ratio of width = cos i / cos r

Total Internal Reflection
Optical Fibre

Dispersion of Light
The separation of white light into it's constituent colours is called as Dispersion.

δ is the angle of deviation.

δv > δy > δr

Prism Formula
μ = sin[A + δm /  2]  / sin[a/2]

δ = A(μ - 1)

Angular Dispersion
Angular DIspersion = δv - δr= A(μv- μr)

Dispersive Power
Dispersive Power =  ω = (δv - δr) / δy

ω = (μv- μr) / (μy - 1)

Scattering of Light
The phenomenon of deflection of light in all possible directions by small particles is called as Scattering.

Rayleigh Scattering
The Intensity of scattered light is inversely proportional to the fourth power of wavelength.

I α 1/λ4