GROUND-STATE-DEPLETION FLUORESCENCE MICROSCOPY - A CONCEPT FOR BREAKING THE DIFFRACTION RESOLUTION LIMIT

We introduce and study a novel concept in farfield fluorescence micros copy fundamentally overcoming the classical diffraction resolution lim it. This is accomlished by reducing the spatial extent of the effectiv e focus of a scanning fluorescence microscope. The reduction is achiev ed by depleting the ground-state energy of the molecules located in th e outer region of the focus. Our theoretical study shows that ground-s tate-depletion fluorescence microscopy has the potential of increasing the resolution of far-held fluorescence microscopy by an order of mag nitude which is equivalent to a lateral resolution of 15 NM.