Quadrifocal diffractive lenses based on the aperiodic silver mean sequence

Abstract

In this work, we present a new quadrifocal diffractive lens designed using the silver mean sequence. The focusing properties of these aperiodic diffractive lenses coined silver mean zone plates are analytically examined. It is demonstrated that, under monochromatic illumination, these lenses present four foci located at certain reduced axial positions given by the Pell numbers that can be correlated with the silver mean sequence. This distinctive optical characteristic is experimentally confirmed.Graphical abstract