cross-relaxation
diffraction
electron transfer
electromagnetic field
energy level
energy level diagram
energy transfer and energy transfer with upconversion
excited state absorption
fluorescence
green fluorescent protein
Kerr effect
multi-photon absorption
nondegenerate two-photon absorption
nonlinear index of refraction
nonparaxial approximation
optically thick sample
paraxial approximation
phosphorescence
plane wave
photo-activated material
photodynamic therapy
pump probe experiment
quantum dots
relaxation
reversible saturable absorption
saturable absorption
self-quenching
single-photon absorption
slowly varying envelope approximation
split-step numerical method
STED microscopy
stimulated emission
three-photon absorption
two-photon absorption
upconversion
Z-scan

Excited state absorption (ESA) is the absorption of a photon from a lower excited state to a higher excited state of an atom, molecule or ion. Excited-state absorption can occur only after an electron has already been excited to the lower excited state. The lower excited state has a higher energy than the ground state level and the higher excited state is higher in energy than the lower excited state. Excited-state absorption from the first excited state is illustrated in the diagram below.

This corresponds to the following Jablonski energy level diagram

See also: Single-photon absorption, Relaxation.

SimphoSOFT® supports modeling excited state absorption. SimphoSOFT® case study of excited-state single-photon absorption in a chromophore AF455. Video describing how to build energy level diagram for optical limiter, containing single- and two-photon absorption transitions, and how to optimize its performance in SimphoSOFT®.

App Notes

	SimphoSOFT® can be purchased as a single program and can be also configured with Energy Transfer add-on , Multi-Beam add-on , Optimization add-on , Z-scan add-on , and MPA Info+ add-on for an additional charge. Please, contact our sales staff for more information e-mail phone: +1 (973) 621-2340
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