Design of a Cascaded Black – Linear Distribution (CBLD) in Circular Aperture and Its Application on Confocal Laser Scanning Microscope (CSLM)

Abstract

A new model of Cascaded Black – Linear Distribution (CBLD) in circular aperture is suggested. Four different models of CBLD are studied. In the 1st model, ten strips are considered where half of them are black and the other half has linear distribution, starting with black strip from the center of the circular aperture. In the 2nd model, twenty strips are considered of equal black and linear zones. In the 3 rd model, a ratio of 2:1 is given for the twenty strips of the CBLD. In the 4th model, annular aperture of linear distribution is considered. We have computed the Point Spread Function (PSF) corresponding to all arrangements and compared with the corresponding PSF for different apertures of circular, annular, and black and white (B/W) transparent circular apertures. The cut-off spatial frequency which is the indication of resolution is investigated in all the described apertures. The Coherent Transfer Function (CTF) using the CBLD apertures is computed. Application of the CBLD arrangement corresponding to the objective and collector lenses in the CLSM using microscopic input images is shown. The reconstructed images using the described models in the CLSM are investigated. A Mat-Lab code is used for the computation of all images.