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 the ground state to transition into the excited state, then what is called a population inversion is created. When light of the appropriate frequency passes through the inverted medium, the photons are either absorbed by the atoms that remain in the ground state or the photons stimulate the excited atoms to emit additional photons of the same frequency, phase, and direction. Since more atoms are in the excited state than in the ground state then an amplification of the input intensity results. The population inversion, in units of atoms per cubic meter, is where "g" and "g" are the degeneracies