Resolution beyond the diffraction limit using frequency-domain field confinement in scanning microscopy

A technique is described to achieve resolution beyond the diffraction limit in scanning microscopy. The approach is based on the generation of a frequency domain focal spot size by the sample itself. Theoretical graphs and experimental results are presented to show the signal generation process. Enhanced resolution is demonstrated in fluorescence imaging of a sensitizing dye. The two-point resolution, and single-point image width, attained in fluorescence imaging should improve to around 150 and 130 nm, respectively, for a proper combination of lenses.