Aspheric Corrector Lens Used with High Numerical Aperature

Aspects of the disclosure relate to correction of aberration in optical systems. In one aspect, correction of aberration can rely on a corrector lens that is movably positioned between an objective lens and an optical member, and that can introduce a perturbation to a convergent beam of light that forms an image at the substantially the focal point of the objective lens. The formed image presents aberration and such a perturbation can correct at least a portion thereof. In another aspect, the corrector lens can embody or can comprise a positive power lens, that introduces the perturbation via, at least in part, a radially symmetric wavefront correction into the convergent beam, where such a correction varies as a fourth power of a radial distance from a central axis of propagation of the convergent beam of light.