When light of suitable frequency incident on the substance, the atom of the substance go to the excited states by absorbing this light. The atom in the excited state come to the ground state or lower energy state by the emission of light or electromagnetic radiation. Einstein predicted that the emission of light or electromagnetic … Read more
Coherence is the term used to describe the phase correlation phenomenon between two waves with respect to time or space. Temporal Coherence Temporal coherence is the correlation between the electric field at a point in the space at time tâ [i.e. E (x, y, z, 1â)]and the electric field at the same point at time … Read more
The term Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. There are main 3 components of Laser device: The active Medium or laser gain medium. A pumping device. A resonant cavity. COMPONENTS OF LASER The basic laser components are active or gain medium, pumping device or source and resonant cavity is … Read more
Before study the properties of photon we must have to know some basic introduction of photon. In 1905, Einstein explained photoelectric effect by considering light consisted of quantum of energy E = hv, Where v is the frequency of the radiation and h=6.63*10-34 Js is Planck’s constant. Gilbert Lewis (an American chemist) in 1926 coined … Read more
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 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
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
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
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
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