Neologism include "laser" (1960) from Light Amplification by Stimulated Emission of Radiation, "robotics" (1941), "agitprop" (1930). The term "neologism" is first attested in English in 1772, borrowed from French "néologisme" (1734). A proponent of a new word or doctrine may be called a neologist. Neologists might study cultural and ethnic vernacular. The term "neologism" has a broader meaning that includes not only "an entirely new lexical item" but also an existing word whose meaning has been altered. Sometimes, the latter process is called "semantic shifting", or "semantic extension". Neologisms are distinct from a person's "idiolect", one's unique patterns of vocabulary, grammar,
Stimulated emission given by where the proportionality constant "B" is known as the "Einstein B coefficient" for that particular transition, and "ρ"("ν") is the radiation density of the incident field at frequency "ν". The rate of emission is thus proportional to the number of atoms in the excited state "N", and to the density of incident photons. At the same time, there will be a process of atomic absorption which "removes" energy from the field while raising electrons from the lower state to the upper state. Its rate is given by an essentially identical equation, The rate of absorption is thus proportional