Wavefront sensing with a Gradient Phase Filter

TL;DR

This paper introduces the Crossed-sine phase sensor (CSPS), a wavefront sensor that achieves high spatial resolution and measurement accuracy using a transparent gradient phase filter, suitable for various optical applications.

Contribution

The paper proposes a novel wavefront sensor design, the CSPS, combining high resolution and accuracy with quasi-achromatic performance, advancing current wavefront sensing technology.

Findings

Achieves measurement accuracy of Lambda/100 RMS

Operates effectively on extended and natural light sources

Offers high spatial resolution at the pupil plane

Abstract

Wavefront sensors have now become core components in the fields of metrology of optical systems, biomedical optics, and adaptive optics systems for astronomy. However, none of the designs used or proposed so far achieve simultaneously a high spatial resolution at the pupil of the tested optics and absolute measurement accuracy comparable to those of modern laser-interferometers. This paper presents an improved wavefront sensor concept that reaches both previous goals. This device named Crossed-sine phase sensor (CSPS) is based on a fully transparent gradient phase filter (GPF) placed at an intermediate location between the virtual pupil and image planes of the tested optics. The theoretical principle of the sensor is described in Fourier optics formalism. Numerical simulations confirm that a measurement accuracy of Lambda/100 RMS is achievable. The CSPS also offers the advantages of being quasi-achromatic and working on spatially or spectrally extended, natural or artificial light sources