Benefits of adding radial phase dimples on scalar coronagraph phase masks

Abstract

Current scalar coronagraph focal plane mask designs are performance-limited by chromaticity. We investigate the effects of adding central Roddier and dual zone phase dimples to scalar vortex masks to improve broadband performance by suppressing the chromatic stellar leakage. We present hybrid designs with radial phase dimples integrated with the sawtooth vortex, wrapped vortex, and cosine phase mask. We show that using these dimples, it is possible to substantially improve the broadband contrast performance of scalar phase masks. We also show that although adding a phase dimple does not increase the sensitivity to low-order aberrations, suppressing the central leakage of scalar vortex coronagraphs does not restore the aberrations sensitivities to their notional state.

References in corpus (5)

• An Eight-Octant Phase-Mask Coronagraph
• Broadband Vector Vortex Coronagraph Testing at NASA's High Contrast Imaging Testbed Facility
• Experimental analysis of the achromatic performance of a vector vortex coronagraph
• Topological Designs for Scalar Vortex Coronagraphs
• Analysis of nulling phase functions suitable to image plane coronagraphy

Cited by in corpus (1)

• Comparative laboratory study of electric field conjugation algorithms