RESOLFT

RESOLFT is an acronym for REversible Saturable OpticaL Fluorescence Transitions.

In a RESOLFT concept the resolution can be approximated by $Delta\; d\; =\; frac\{lambda\}\{pi\; cdot\; ncdotsqrt\{frac\{I\}\{Isat\}$, whereby Isat is the characteristic intensity required for saturating the transition, and I denotes the intensity applied. If the minima are produced by focusing optics with a numerical aperture nsin α, the minimal distance at which two identical objects can be discerned is $Delta\; d\; =\; frac\{lambda\}\{2ncdotsinalphacdotsqrt\{1+frac\{I\}\{Isat\}$ which can be regarded as an extension of Abbe’s equation. The diffraction-unlimited nature of the RESOLFT family of concepts is reflected by the fact that the minimal resolvable distance can be continuously decreased by increasing $varsigma\; =\; frac\{I\}\{Isat\}$. Hence the quest for nanoscale resolution comes down to maximizing $varsigma\; =\; frac\{I\}\{Isat\}$. This is possible by increasing I or by lowering Isat. [ [http://www.wissenschaft-online.de/gbm/fall05/homepage/abstract_detail.php?artikel_id=1142 Brief summary] of the RESOLFT equations developed by the Max Planck Institute for Biophysical Chemistry.]

References

ee also

*microscope
*STED microscope