Wave Optics - Reflection

Description:

• When light falls on the surface of a material it is either re-emitted without change in frequency or is absorbed in the material and turned into heat.

• When the re-emitted light is returned into the same medium from which it comes, it is called reflected light and the process is known as reflection.

• The incident ray is a plane wavefront that hits the reflecting surface after reflection the reflected ray is also a plane wavefront.

• As we know from the Ray theory of light, angle of incidence is equal to the angle of reflection, so the wave reflection should also satisfy the same criteria. To prove this, we would use the following figure -

In △ABC and △ADC

AC is common

∠B = ∠D = 90⁰

AD = BC

∴ △ABC and △ADC are Congruent triangles.

∠i = ∠r

i.e. Angle of Incidence = Angle of Reflection