Scientific terminology laser is commonly written in small letters. It has even produced secondary acronyms such as LASIK (Laser-ASsisted in Situ Keratomileusis). A related acronym and neologism maser (Microwave Amplification by Stimulated Emission of Radiation) is much less known. Nevertheless, it is commonly written in small letters. On the contrary, acronym SPASER (Surface Plasmon Amplification by Stimulated Emission of Radiation) is capitalized. Many scientific acronyms or abbreviations reflect the artistic sense of their creators, e.g., etc. (see also List of astronomy acronyms). Scientific terminology Scientific terminology is the part of the language that is used by scientists in the context of their
Stimulated emission difference in energies between the two states as a photon. The photon will have frequency "ν" and energy "hν", given by: where "h" is Planck's constant. Alternatively, if the excited-state atom is perturbed by an electric field of frequency "ν", it may emit an additional photon of the same frequency and in phase, thus augmenting the external field, leaving the atom in the lower energy state. This process is known as stimulated emission. In a group of such atoms, if the number of atoms in the excited state is given by "N", the rate at which stimulated emission occurs is