Jablonski diagram
![A Jablonski diagram showing the excitation of molecule A to its singlet excited state (1A*) followed by intersystem crossing to the triplet state (3A) that relaxes to the ground state by phosphorescence.](/Images/godic/202501/21/JablonskiSimple3027.png")
![A Jablonski diagram representing Förster resonance energy transfer (FRET)](/Images/godic/202501/21/FRET-Jablonski-diagram3027.jpg")
![Jabłoński-Diagramm](/Images/godic/202501/21/Jablonski_Diagramm_Deutsch3027.png")
A Jablonski diagram is a diagram that illustrates the electronic states of a molecule and the transitions between them. The states are arranged vertically by energy and grouped horizontally by spin multiplicity. Nonradiative transitions are indicated by squiggly arrows and radiative transitions by straight arrows. The vibrational ground states of each electronic state are indicated with thick lines, the higher vibrational states with thinner lines. The diagram is named after the Polish physicist Aleksander Jabłoński.