Unfolded Physics

LASERs play a very vital role in many fields and industries. What makes it so special? It's characteristics. Lasers have: 1.High directionality 2.High monochromaticity 3.A high degree of coherence 4.High brightness So let's understand each one in detail. 1. High directionality: The lasers are made of active medium placed in between two reflecting resonator mirrors one which can partially reflect and the other which can fully reflect the light. Any photon travelling in a direction away from the cavity axis reflects away by the mirrors within a few reflections and is thus not allowed to propagate further, thus the beam drawn from the output mirror is highly parallel and directional. The degree of directionality is expressed as the divergence .  Minimum spot point:  The curvature of the mirror confines the light within the cavity and causes the beam to narrow down to a radius w o    and this is called a minimum spot point. The ...

LASER stands for Light Amplification through Stimulated Emission. The theoretical basis was given by Albert Einstein and the first laser was developed by T.H. Mainmann. LASERs work on 3 main processes. They are Stimulated Absorption, Spontaneous Emission and Stimulated Emission . Stimulated Absorption: When a photon with energy hf, is incident on an electron of an atom present in the ground state, the electron excites to higher energy levels by absorbing the photon. This process is directly proportional to the number of electrons in the ground state.  Spontaneous Emission: The excited electron stays for 100 nanoseconds in the excited state and then emits a photon i.e, releases energy which is equal to the difference between energies of the higher energy level and the minimum energy level, to get back to ground state. This process is directly proportional to the number of electrons in the excited state. Stimulated Emission: When the electron moves to a metastab...

           HEISENBERG'S UNCERTAINTY PRINCIPLE   It becomes a bit perplexing and puzzling to know that if you are reduced into a quantum sized body then your position and momentum are not certain. If you are not aware of anything like this before then it surely puts your mind into the blank area where this statement raises numerous questions and some don't even agree with this. But this statement is the foundation of the quantum theories which have remarkably and marvellously changed the entire world's thinking towards science. It looks nonsensical to say that you are present everywhere in a probable region and your position is uncertain till someone measures it at a certain time. But it is true no matter what we think. The statement says that we cannot know both the position and momentum of a subatomic particle simultaneously. This theory says that the change in momentum times the change in position is always greater than or...