Förster resonance energy transfer is named after the German scientist Theodor Förster.[7] When both chromophores are fluorescent, the term "fluorescence resonance energy transfer" is often used instead, although the energy is not actually transferred by fluorescence.[8][9] In order to avoid an erroneous interpretation of the phenomenon that is always a nonradiative transfer of energy (even when occurring between two fluorescent chromophores), the name "Förster resonance energy transfer" is preferred to "fluorescence resonance energy transfer;" however, the latter enjoys common usage in scientific literature.[10] It should also be noted that FRET is not restricted to fluorescence. It can occur in connection with phosphorescence as well