Search results
Results From The WOW.Com Content Network
Photoluminescence (abbreviated as PL) is light emission from any form of matter after the absorption of photons (electromagnetic radiation). [1] It is one of many forms of luminescence (light emission) and is initiated by photoexcitation (i.e. photons that excite electrons to a higher energy level in an atom), hence the prefix photo- . [ 2 ]
Fluorescent minerals emit visible light when exposed to ultraviolet. Fluorescent marine organisms Fluorescent clothes used in black light theater production, Prague. Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation.
In fluorescence spectra, it is always seen at a constant wavenumber difference relative to the excitation wavenumber e.g. the peak appears at a wavenumber 3600 cm −1 lower than the excitation light in water. Other aspects to consider are the inner filter effects. [8] [9] These include reabsorption. Reabsorption happens because another ...
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs.
Piezospectroscopy can be used on any material that exhibits fluorescence, but is almost exclusively used on samples containing alumina because of the presence of chromium ions, either as part of the composition or as an impurity, that greatly increase the fluorescent response.
Chlorophyll fluorescence is a widely-used proxy for the quantity (biomass) of microscopic algae in the water. In the lab after water sampling, researchers extract the pigments out of a filter that has phytoplankton cells on it, then measure the fluorescence of the extract in a benchtop fluorometer in a dark room. [7]
The chloride ion is a well known quencher for quinine fluorescence. [2] [3] [4] Quenching poses a problem for non-instant spectroscopic methods, such as laser-induced fluorescence. Quenching is made use of in optode sensors; for instance the quenching effect of oxygen on certain ruthenium complexes allows the measurement of oxygen saturation in ...
Photoluminescence, a result of the absorption of photons Fluorescence, traditionally defined as the emission of light that ends immediately after the source of excitation is removed. As the definition does not fully describe the phenomenon, quantum mechanics is employed where it is defined as there is no change in spin multiplicity from the ...