SUPERRESOLUTION IN CONFOCAL SCANNING MICROSCOPY .5. AXIAL SUPERRESOLUTION IN THE INCOHERENT CASE

One of the basic properties of confocal scanning laser microscopy (CSLM) is the possibility of high axial resolution in the case of fluorescent objects. As a consequence 3D images of 3D objects can be obtained. In the previous papers of this series it has been demonstrated that an improvement of lateral resolution in CSLM (lateral super-resolution) can be obtained if, at each step of the scanning procedure, the full image is detected in the image plane and these data are inverted to estimate the object at the confocal point. In this paper we prove that the same data contain sufficient information for improving also the axial resolution of CSLM (axial superresolution). The analysis is performed in the case of a simplified model, i.e. two-dimensional objects (one lateral plus one axial dimension) and lenses with a small numerical aperture.