Zernike Mode Sorting with Vortex Phase Filters: Perfect Coronagraphs and Ideal Wavefront Sensors

TL;DR

This paper introduces a novel optical mode sorting method using vortex phase filters to efficiently separate Zernike polynomials, enhancing wavefront sensing and coronagraphy for high-contrast imaging.

Contribution

It presents an architecture for lossless, crosstalk-free Zernike mode sorting using conventional optics and vortex phase plates, advancing optical sensing capabilities.

Findings

Achieves lossless, crosstalk-free Zernike mode separation

Proposes an optical system saturating quantum sensitivity limits

Improves high-contrast imaging for exoplanet detection

Abstract

Spatial mode sorting has come to prominence as an optical processing modality capable of saturating fundamental limits to numerous sensing tasks including wavefront sensing, coronagraphy, and superresolution imaging. But despite their promising theoretical advantages, contemporary mode sorters often feature large crosstalk, high loss, or sort modes that are poorly adapted to conventional imaging systems (e.g., Hermite- and Laguerre-Gauss). Here, we introduce an alternative architecture that sorts spatial modes natural to circularly symmetric apertures: Zernike polynomials. Using conventional optics hardware and even-order vortex phase plates, we show how to assemble a series of vortex phase filters that can in principle separate the various Zernike polynomials losslessly and without crosstalk. This idea is demonstrated via application to wavefront sensing and coronagraphy, where we propose an optical system that saturates the quantum sensitivity limits to both tasks. We expect our work to prove useful for high-contrast imaging of extrasolar planets, improving both wavefront control and coronagraph performance.