Using multi-element detectors to create optimal apertures in confocal microscopy

A detection pinhole is used in confocal microscopy to reduce contributions from image planes outside of the focal plane. The size of this pinhole may be varied but the idea of a fixed circular aperture is ubiquitous. Here it is shown that an ideal detection aperture varies as a function of the spatial-frequency being imaged. A method for calculating such detection apertures is given, an example calculation is shown and a detector array is suggested as a means to approximate these varying detection apertures