Matthew Johns with Rolfe Petschek

Nanometer Optical Imaging of Fluorescent Dyes

If a single fluorescent dye molecule is near the image plane of a far-field microscope, it is possible, by carefully analyzing the image of the particle in an ordinary light microscope, to find the position of the particle in the directions perpendicular to the axis of the microscope to accuracy significantly better than the wavelength of light that is the “Rayleigh limit.”  We will examine theoretically how these limits can be improved by interfering light on different paths or with different polarizations, and then examining simultaneously the images that these interferences form.  Various schemes for making these interferences will be examined to find which will result in the best signal to noise for various combinations of the 3-dimensional position of the particle and its orientation.