enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Jablonski diagram - Wikipedia

    en.wikipedia.org/wiki/Jablonski_diagram

    The changes between these levels are called "transitions" and are plotted on the Jablonski diagram. 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.

  3. Energy level - Wikipedia

    en.wikipedia.org/wiki/Energy_level

    An increase in energy level from E 1 to E 2 resulting from absorption of a photon represented by the red squiggly arrow, and whose energy is h ν. A decrease in energy level from E 2 to E 1 resulting in emission of a photon represented by the red squiggly arrow, and whose energy is h ν.

  4. Absorption (electromagnetic radiation) - Wikipedia

    en.wikipedia.org/wiki/Absorption_(electromagnetic...

    By recording the attenuation of light for various wavelengths, an absorption spectrum can be obtained. In physics, absorption of electromagnetic radiation is how matter (typically electrons bound in atoms) takes up a photon's energy—and so transforms electromagnetic energy into internal energy of the absorber (for example, thermal energy). [1]

  5. Stokes shift - Wikipedia

    en.wikipedia.org/wiki/Stokes_shift

    Stokes fluorescence is the emission of a longer-wavelength photon (lower frequency or energy) by a molecule that has absorbed a photon of shorter wavelength (higher frequency or energy). [6] [7] [8] Both absorption and radiation (emission) of energy are distinctive for a particular molecular structure. If a material has a direct bandgap in the ...

  6. Electron excitation - Wikipedia

    en.wikipedia.org/wiki/Electron_excitation

    Within a semiconductor crystal lattice, thermal excitation is a process where lattice vibrations provide enough energy to transfer electrons to a higher energy band such as a more energetic sublevel or energy level. [3] When an excited electron falls back to a state of lower energy, it undergoes electron relaxation (deexcitation [4]).

  7. Franck–Condon principle - Wikipedia

    en.wikipedia.org/wiki/Franck–Condon_principle

    Franck–Condon principle energy diagram. Since electronic transitions are very fast compared with nuclear motions, the vibrational states to and from which absorption and emission occur are those that correspond to a minimal change in the nuclear coordinates.

  8. Zero-phonon line and phonon sideband - Wikipedia

    en.wikipedia.org/wiki/Zero-phonon_line_and...

    The zero-phonon line is an optical analogy to the Mössbauer lines, which originate in the recoil-free emission or absorption of gamma rays from the nuclei of atoms bound in a solid matrix. In the case of the optical zero-phonon line, the position of the chromophore is the physical parameter that may be perturbed, whereas in the gamma ...

  9. Two-photon absorption - Wikipedia

    en.wikipedia.org/wiki/Two-photon_absorption

    Schematic of energy levels involved in two photons absorption. In atomic physics, two-photon absorption (TPA or 2PA), also called two-photon excitation or non-linear absorption, is the simultaneous absorption of two photons of identical or different frequencies in order to excite an atom or a molecule from one state (usually the ground state), via a virtual energy level, to a higher energy ...