Use of objective lenses with slit pupil functions in the imaging of line structures

We consider the imaging of line structures in confocal imaging systems and show that some advantages result if we employ a slit pupil function in one of the lenses. As an example it is found that the gradient of the image of a straightedge is 17.8% sharper than in a traditional confocal microscope. Another attraction is that theoretical imaging calculations are often possible in terms of simple analytic functions. Experimental results and images are presented which are compared with traditional confocal systems as well as those employing incoherent slit detectors.