Term: laser
https://doi.org/10.1351/goldbook.L03459

Definition:
A source of ultraviolet, visible, or infrared radiation which produces light amplification by stimulated emission of radiation from which the acronym is derived. The light emitted is coherent except for superradiance emission. The essential elements of a laser are: 1, an active medium; 2, a pumping process to make a population inversion; and 3, suitable geometry of optical feedback elements. The active medium consists of a host material (gas, liquid or solid) containing an active species.

Related Terms:
1) lasing (http://doi.org/10.1351/goldbook.L03479).
2) ultraviolet (http://doi.org/10.1351/goldbook.UT07492).
3) visible (http://doi.org/10.1351/goldbook.VT07496).
4) infrared (http://doi.org/10.1351/goldbook.IT07399).
5) stimulated emission (http://doi.org/10.1351/goldbook.S06015).
6) superradiance (http://doi.org/10.1351/goldbook.S06145).
7) active medium (http://doi.org/10.1351/goldbook.A00106).
8) population inversion (http://doi.org/10.1351/goldbook.P04759).
9) active species (http://doi.org/10.1351/goldbook.A00110).
10) argon ion laser (http://doi.org/10.1351/goldbook.A00439).
11) atomic laser (http://doi.org/10.1351/goldbook.A00495).
12) co<sub>2</sub> laser (http://doi.org/10.1351/goldbook.C00828).
13) chemical laser (http://doi.org/10.1351/goldbook.C01028).
14) copper vapour laser (http://doi.org/10.1351/goldbook.C01338).
15) crystal laser (http://doi.org/10.1351/goldbook.C01430).
16) diode laser (http://doi.org/10.1351/goldbook.D01747).
17) dye laser (http://doi.org/10.1351/goldbook.D01870).
18) excimer laser (http://doi.org/10.1351/goldbook.E02243).
19) free electron laser (http://doi.org/10.1351/goldbook.F02514).
20) free-running laser (http://doi.org/10.1351/goldbook.F02521).
21) gas laser (http://doi.org/10.1351/goldbook.G02585).
22) glass laser (http://doi.org/10.1351/goldbook.G02638).
23) helium–cadmium laser (http://doi.org/10.1351/goldbook.H02765).
24) helium–neon laser (http://doi.org/10.1351/goldbook.H02768).
25) ion laser (http://doi.org/10.1351/goldbook.I03219).
26) krypton ion laser (http://doi.org/10.1351/goldbook.K03417).
27) mode-locked laser (http://doi.org/10.1351/goldbook.M03959).
28) molecular laser (http://doi.org/10.1351/goldbook.M03991).
29) neodymium laser (http://doi.org/10.1351/goldbook.N04103).
30) nitrogen laser (http://doi.org/10.1351/goldbook.N04160).
31) organic dye laser (http://doi.org/10.1351/goldbook.O04325).
32) q-switched laser (http://doi.org/10.1351/goldbook.Q04967).
33) ruby laser (http://doi.org/10.1351/goldbook.R05427).
34) solid state lasers (http://doi.org/10.1351/goldbook.S05736).

Source: PAC, 1995, 67, 1913. 'Nomenclature, symbols, units, and their usage in spectrochemical analysis-XV. Laser-based molecular spectroscopy for chemical analysis - laser fundamentals (IUPAC Recommendations 1995)' on page 1915 (https://doi.org/10.1351/pac199567111913)

Citation: 'laser' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.L03459

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