Signal level in a confocal scanning microscope using step-index optical fibres

Abstract

The signal level in a fibre-optical confocal scanning microscope using step-index profile fibres is investigated. The dependence of the signal level on the fibre parameter V is studied. Two different systems are investigated. For the first case of a system employing a point source and a fibre for collection, the maximum value of signal level for a given V is given. The signal level for a second arrangement, when the system uses a fibre for both illumination and collection, is also studied. It is found that, in both cases, optimum overall performance is achieved for large values of V.