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 frequency, phase, polarization, and direction of propagation as the incident photons. The photons involved are thus mutually coherent. When a population inversion (formula_6) is present, therefore, optical amplification of incident radiation will take place. Although energy generated by stimulated emission is always at the exact frequency of the field which has stimulated it, the above rate equation refers only to excitation at the particular optical frequency formula_9 corresponding to the energy of the transition. At frequencies offset from formula_9 the strength of stimulated (or spontaneous) emission will be decreased according to the so-called line shape. Considering only homogeneous broadening affecting