Stimulated emission (also known as induced emission) is the process by which an electron is induced to jump from a higher energy level to a lower one by the presence of electromagnetic radiation at (or near) the frequency of the transition.
In contrast, most "conventional" lasers (such as the ruby laser) rely on stimulated electronic transitions to amplify light.
European emission standards | Positron emission tomography | spontaneous emission | positron emission tomography | Emission Impossible | Stimulated emission | Spontaneous emission | Optically stimulated luminescence | Low-ionization nuclear emission-line region | Bharat Stage emission standards | Thermal Emission Spectrometer (TES) | Thermal Emission Spectrometer | stimulated emission | Spurious emission | Soft X-ray emission spectroscopy | Self-amplified stimulated emission | nocturnal emission | Emission spectrum | Advanced Spaceborne Thermal Emission and Reflection Radiometer |
Albert Einstein created the foundations for the laser and maser in 1917, via a paper in which he re-derived Max Planck’s law of radiation using a formalism based on probability coefficients (Einstein coefficients) for the absorption, spontaneous emission, and stimulated emission of electromagnetic radiation.
However, this was ultimately changed to laser for "Light Amplification by Stimulated Emission of Radiation." Gordon Gould is credited with creating this acronym in 1957.