Explanation : The word “laser” is actually an acronym for light amplification by stimulated emission of radiation. Atoms or molecules of the active medium that have been excited to a higher energy level are stimulated by a passing photon to relax to a lower energy level and emit a photon that is indistinguishable from the passing photon, thereby increasing the number of photons like the incident one.
555555555523. Once the active medium is excited, the first photons of light are produced by which physical process? (a) Blackbody radiation (b) Spontaneous emission (c) Synchrotron radiation (d) Planck’s oscillation