Moment analysis of focus-diverse point spread functions for modal wavefront sensing of uniformly illuminated circular-pupil systems

TL;DR

This paper introduces a novel focus-diverse PSF method for modal wavefront sensing using image moments, which simplifies the wavefront estimation process especially for highly aberrated, high SNR systems.

Contribution

It presents a new wavefront sensing approach based on focus-diverse PSFs and image moment analysis, offering a linear solution for modal coefficients.

Findings

Potential for accurate wavefront estimation in high aberration scenarios

Decoupling of wavefront coefficients via focus-diversity

Proof-of-concept simulations demonstrate feasibility

Abstract

A new concept of using focus-diverse point spread functions (PSFs) for modal wavefront sensing (WFS) is explored. This is based on relatively straightforward image moment analysis of measured PSFs, which differentiates it from other focal-plane wavefront sensing techniques (FPWFS). The presented geometric analysis shows that the image moments are non-linear functions of wave aberration coefficients, but notes that focus-diversity (FD) essentially decouples the coefficients of interest from others, resulting in a set of linear equations whose solution corresponds to modal coefficient estimates. The presented proof-of-concept simulations suggest the potential of the concept in WFS with strongly aberrated high SNR objects in particular.