Fluorescence excitation

What is called the he excitation energy of 2 photons, or more?

We are talking about biphoton, triphoton or more generally multiphoton energy. In this particular case Fluorescence excitation is further down the spectrum (infrared) resignation.

Electrons are not all the same.
over the same layer or electronic sub-layer once excited. Likewise they will not be on the same electronic undercoat after their relaxation. So it was not a value but a range of energy values ​​/ length of water that will be absorbed or emitted by a fluorochrome.

But each fluorochrome one can establish a front-end spectrum capable of ending and a Fluorescence wavelength spectrum.

What are the spectra defined characteristics?

1 absorption length (excitation) and emission length (fluorescence)
maximum, specific for each fluorochrome.
2 the excitation length is smaller than the fluorescence length (in
fluorescence monophoton)
3 a symmetry of excitation and emission spectra.
4 The gap of Stockes = difference between the maximum values ​​of excitation and emission.

The difference of Stokes is great, the simplest is the discrimination of fluorescence.
When illuminating (excites) the fluorochrome in length corresponding to its maximum absorption, the fluorochrome emits under all its emission spectrum, the total length for the one of the publicity emits its maximum Max.

If on the other hand one declared a maximum length different from its absorption,the fluorochrome also emits under all its emission spectrum, the emission maximum does not change, on the other hand, the fluorescence intensity is lower. It is therefore important to optimize the choice of excitation and emission filters to recover as much fluorescence as possible.

Olympus fluorescent Image galleries