Fluorescence

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Fluorescence \Flu`o*res"cence\, n. [From {Fluor}.] (Chemistry,
     Optics)
     A luminescence emitted by certain substances due to the
     absorption of radiation at one wavelength, and the almost
     instantaneous re-emission of radiation at another, usually
     longer wavelength. The re-radiation stops almost as soon as


     the incident radiation is halted, thus distinguishing this
     phenomenon from {phosphorescence}, in which re-radiation of
     light may continue for some time after the incident radiation
     is halted.
  
     Note: The color of the radiated light typically differs from
           the apparent color of the material, as when green
           crystals of fluor spar afford blue reflections. It is
           due not to the difference in the color of a distinct
           surface layer, but to the power which the substance has
           of modifying the light incident upon it, by first
           absorbing the light to achieve an excited state, and
           then radiating light to resume the ground energy level.
           The light emitted by fluorescent substances is in
           general of longer wavelength than the incident light.
           The radiation can also be induced by ionizing radiation
           which is not electromagnetic, such as alpha or beta
           rays, and cathode rays. This property is possessed by
           fluorspar, uranium glass, sulphide of calcium, and many
           other substances. It finds use in analytical
           instruments to detect or measure radiation, and in some
           commercial applications.
           [1913 Webster +PJC]

From WordNet (r) 2.0 [wn]:

  fluorescence
       n : light emitted during absorption of radiation of some other
           (invisible) wavelength

From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:

  28 Moby Thesaurus words for "fluorescence":
     autoluminescence, bioluminescence, cathode luminescence,
     chemicoluminescence, chemiluminescence, corposant,
     crystalloluminescence, double corposant, electroluminescence,
     fata morgana, fox fire, ignis fatuus, luciferase, luciferin,
     luminescence, luminophor, marshfire, noctiluscence, phosphor,
     phosphorescence, photoluminescence, radioluminescence,
     thermoluminescence, tribofluorescence, triboluminescence,
     tribophosphorescence, wisp, witch fire