A three-zone phase-only pupil filter for improving lateral resolution

In order to achieve the lateral superresolution imaging of an optical imaging system, a three-zone and multi-values phase-only pupil filter is designed to achieve the superresolution of full width at half maximum G(L)=0.65, Strehl ratio S=0.118 and ratio of maximal side lobe intensity with pupil and main lobe intensity without pupil M=0.912, which is based on pupil filter techniques and uses genetic optimizing algorithm. A three-zone phase-only pupil supperresolution confocal microscopy imaging method is established by integrating the three-zone and multi-values phase-only pupil filter designed with confocal microscopy system (CMS). Simulation results indicate that, when CMS lateral superresolution of G(L)=0.56, S=0.118 is achieved, the approach proposed can suppress the increasing of side lobe M caused by three-zone phase-only superresolution pupil from 0.912 to 0.02, and obviously improve CMS lateral resolution and imaging quality. A three-zone and two-value phase-only pupil filter is also designed, and its central intensity is slightly smaller than that of the multi-values pupil designed for the same G, however, its process technology is superior, it is better for practical application. It is therefore concluded that the design method proposed provides an effective technical approach for the design of superresolution pupil filters.