Ever wondered what is laser?
L aser is a contrivance (device) which produces a very intense, monochromatic, coherent and highly unidirectional beam of light. Laser is an acronym (short form) for Light Amplification by Stimlated Emission of Radiation. This is a concise description of what a laser does. The key to the 'light amplification' is in a process that is very rare in nature, the stimulated emission of a photon (radiation) by an atom in an excited state. Before the invention of laser, MASER was invented which abbreviated form of Microwave Amplification by Stimulated Emission of. Radiation and it produces such a beam of microwave. The principle of MASER is identical to that of laser. Due to this reason, laser is also called optical MASER. Now a days, IRASER (Infrared Amplification by Stimulated Emission of Radiation) and BASER (Boson Amplification by Stimulated Emission of Radiation) have been developed. Fermions (to be discussed later) cannot be amplified using the principle involved in t