Modelling the first- and third-order properties of conceptual thick lenses by using three air-spaced thin lenses

Abstract

A virtual thick-lens module comprising three air-spaced thin lenses is proposed, which is able to have the identical first-order quantities and third-order Seidel aberrations for just real thick lenses, or groups or components within any thick lens, hence it is capable of studying the aberration behaviours of conceptual lenses without detailed structures. The three thin-lens powers are first evaluated to match the required first-order quantities. Then the aberrations of each thin lens are solved to satisfy the given total aberrations. When the incident rays are changed, each thin lens will induce new aberrations according to the thin-lens formulae. The new system aberrations of the thick module are obtained by adding individual thin-lens aberrations. The module can be directly applied to finite and infinite conjugates, focal and afocal lenses, as well as telecentric and non-telecentric lenses. Examples are given to simulate two real lenses and to optimise the balanced aberrations of a conceptual zoom lens.