Fractal conical lenses

A conical lens is an optical element that produces a continuous focal segment along the optical axis. In this paper we introduce a more general optical device: the fractal conical lens (FCL). As the profile of a FCL is generated using the Cantor function, we show that a classical conical lens is a particular case of these fractal lenses. FCLs are distinguished by the fractal focal segments they produce along the optical axis. The influence of the Fresnel number on the axial irradiance generated by these lenses is investigated.