Search results
Results from the WOW.Com Content Network
An overview of absorption of electromagnetic radiation.This example shows the general principle using visible light as a specific example. A white light source—emitting light of multiple wavelengths—is focused on a sample (the pairs of complementary colors are indicated by the yellow dotted lines).
Radiative transitions involve either the absorption or emission of a photon. As mentioned above, these transitions are denoted with solid arrows with their tails at the initial energy level and their tips at the final energy level. Nonradiative transitions arise through several different mechanisms, all differently labeled in the diagram.
Jablonski diagram of FRET with typical timescales indicated. The black dashed line indicates a virtual photon.. Förster resonance energy transfer (FRET), fluorescence resonance energy transfer, resonance energy transfer (RET) or electronic energy transfer (EET) is a mechanism describing energy transfer between two light-sensitive molecules (chromophores). [1]
The matter-composition of the medium through which the light travels determines the nature of the absorption and emission spectrum. These bands correspond to the allowed energy levels in the atoms. Dark bands in the absorption spectrum are due to the atoms in an intervening medium between source and observer. The atoms absorb certain ...
The emission spectrum of iron. Emission is a process by which a substance releases energy in the form of electromagnetic radiation. Emission can occur at any frequency at which absorption can occur, and this allows the absorption lines to be determined from an emission spectrum.
A Jablonski diagram describing the mechanism of triplet-triplet annihilation. The energy of the first triplet excited state (T 1) is transferred to a second triplet excited state (T 1), resulting in (1) the first T 1 returning to the singlet ground state S0 and (2) the second T 1 promoting to the singlet excited state (S 1).
A wide variety of absorption band and line shapes exist, and the analysis of the band or line shape can be used to determine information about the system that causes it. In many cases it is convenient to assume that a narrow spectral line is a Lorentzian or Gaussian , depending respectively on the decay mechanism or temperature effects like ...
As a result, both absorption and emission produce molecules in vibrationally excited states. The potential wells are shown favoring transitions with changes in ν. The Franck-Condon principle describes the intensities of vibronic transitions, or the absorption or emission of a photon. It states that when a molecule is undergoing an electronic ...