All-optical magnetic superresolution with binary pupil filters

Abstract

A method to produce magnetic superresolution in all-optical magnetic storage is proposed. Two-zone amplitude-only and phase-only filters are designed to improve the quality of the superresolved magnetization pattern, to increase the magnetic spot intensity, to reduce the magnetic spot size, and to control the sidelobe effect. A procedure for designing a rotationally symmetric pupil-plane mask to control the magnetization intensity distribution near focus is presented. As a practical implementation, we have applied our method to obtain superresolving two-zone phase filters that can improve the all-optical magnetic recording density.