Three-dimensional coherent transfer functions in fiber-optical confocal scanning microscopes

Abstract

After analyzing the three-dimensional image formation in fiber-optical confocal scanning microscopes, a three-dimensional effective point-spread function is introduced. For both reflection-mode and transmission-mode microscopes of small circular aperture, analytical expressions for the three-dimensional coherent transfer functions are derived. The relation between the three-dimensional and the two-dimensional (for thin objects) coherent transfer functions in these microscopic systems is further investigated. Three-dimensional numerical plots of the coherent transfer functions reveal their dependence on the fiber spot size.