## Young’s double slit experiment derivation

One of the first demonstration of the intererference of light waves was given by Young – an English physicist in 1801. We have learnt that two essential conditions to obtain an interference phenomenon are : Two sources should be coherent and Two coherent sources must be placed close to each other as the wavelength of … Read more

## Methods of Reducing Spherical Aberration

How to Reduce Spherical Aberration The following 5 methods are usually used to reduce the spherical aberration. By Stop Method. By using plano-convex lenses. By using two convergent lenses separated by a finite distance. By using crossed lens. By using the combination of suitable concave and convex lens. By Stop Method Since spherical aberration of … Read more

## Aberration in Optics and Types of Aberration

Aberration in Optics In the simple theory of image formation by lenses, it is assumed that an object is situated very close to the principal axis and each point object produces a corresponding point image. In other words, a lens produces a perfect or an ideal image of an object. But in reality, a lens … Read more

## Combination of Lenses

Suppose we have two lenses of focal lengths f1 and f2 separated by a distance x as shown in fig below. L1, L2 correspond to the position of two lenses while the transverse planes through L1 and L2 will serve as input and output planes respectively. AB is the incident ray and CD is the … Read more

## Translation Matrix

The matrix Tm is called Translation Matrix. The matrices can be used to find the position of the final image. The method of writing linear equations for the coordinates of the paraxial rays and then transforming them into the matrices for the purpose of optical analysis is called Matrix method in optics. When a ray … Read more

## Fermat’s Principle of Least Time

What is fermat’s principle? This principle states that the light always travels that path in a medium from one point to another point which takes the minimum (i.e least) time. Fermat’s Principle of Least Time Consider a medium of refractive index n. The time taken by light ray to travel a distance dS in the … Read more

## Optical Path and Geometrical Path

The branch of physics which deals with the study of optical phenomenon like reflection, refraction, dispersion, interference, diffraction, polarization etc. is known as optics. Optics is classified into two categories: the geometrical optics and physical optics. Geometrical optics is a branch of optics which deals with the study of optical phenomenon without considering the nature … Read more

## Huygens principle of secondary wavelets

Huygens principle of Wave Theory Huygens Principle helps us to find the position of a given wavefront at any instant if we know its present position. A wavefront is defined as the continuous locus of all particles of a medium vibrating in the same phase. For example, when a stone is dropped into a Pound … Read more

## Michelson Interferometer- Definition, Principle, Construction and Working, Applications.

An interferometer is an instrument that uses interference phenomenon in the measurement of the wavelength of light in terms of standard of length or the measurement of distance in terms of the known wavelength of the light.  In this article, we will explore the Definition, Principle, construction and working of the Michelson Interferometer, its components, … Read more