Optics

Optics

Reflection and refraction of light waves - total internal reflection interference Michelson interferometer - Theory of air wedge and experiment

Introduction

Light is a form of energy to which our eye is sensitive. While light itself is 'invisible’ to our eye, it makes objects visible, mainly by the process of scattering.

Light energy exhibits dual nature, that of a particle and a wave. The wave nature of light can be understood on the basis of Young's double slit experiment. The wave character of light manifests itself in phenomena such as interference, diffraction, polarization etc.

On an atomic scale when light energy interacts with matter it exhibits particle nature. The particle aspect of light can be understood on the basis of Quantum theory of radiation proposed in 1900 by the German physicist Max Planck. According to this theory, light energy is emitted and absorbed by matter in packets called Quantum of radiation.

"Optics is the branch of physics which deals with the source of light, nature of light, its properties and effects”.

Optics is broadly classified into two branches:

(a) Geometrical optics (b) Physical optics.

Geometrical optics deals with the ray concept of light. It deals with the optical phenomena such as reflection, refraction and their applications to optical instruments.

Physical optics deals with the wave nature of light. It deals with the phenomena such as interference, diffraction and polarization etc.