SPIE BiOS, 2015
We present a method for Z-super-localization in fluorescence microscopy, based on conical diffraction. By using a thin biaxial crystal, the Point Spread Function (PSF) shape of an objective is made to depend strongly on the z coordinate. This z dependence is then exploited to localize fluorescent emitters axially with a great precision. We study how this method can be used for single molecule imaging with a global assessment by Fisher information analysis. Preliminary experiments demonstrate that this technique can obtain resolutions of tens of nm with the use of high NA objectives.