Characterization and correction of spherical aberration due to glass substrate in the design and fabrication of Fresnel zone lenses

TLDR: Two novel schemes for correction of spherical aberration are proposed and studied and the accuracy of the proposed aberration correction schemes is validated.

Abstract: As with a conventional lens, a Fresnel zone lens (FZL) can be used to image objects at infinity or nearby In the latter case, the FZL converts a diverging spherical wavefront into a converging spherical wavefront The glass substrate on which the FZL is fabricated introduces spherical aberration resulting in a shift of the image plane and blurring of the image Two novel schemes for correction of this spherical aberration are proposed and studied in this paper To demonstrate them, FZLs are designed with and without aberration correction They are fabricated using electron beam direct writing The devices are evaluated and the accuracy of the proposed aberration correction schemes is validated