Toward practical weak measurement wavefront sensing: spatial resolution and achromatism

TL;DR

This paper improves weak measurement wavefront sensors by using a Savart plate and achromatic retarder to achieve achromatic and high-resolution wavefront sensing, demonstrated through experimental wavefront reconstruction and Zernike coefficient analysis.

Contribution

It introduces a novel achromatic wavefront sensing method using a Savart plate and retarder, enhancing practical applicability in biomedical imaging.

Findings

Achieved achromatic wavefront sensing with improved spatial resolution.

Successfully reconstructed wavefronts and extracted Zernike coefficients across multiple wavelengths.

Demonstrated potential for real-world biomedical imaging applications.

Abstract

The weak measurement wavefront sensor detects the phase gradient of light like the Shack-Hartmann sensor does. However, the use of one thin birefringent crystal to displace light beams results in a wavelength-dependent phase difference between the two polarization components, which limits the practical application. Using a Savart plate which consists of two such crystals can compensate for the phase difference and realize achromatic wavefront sensing when combined with an achromatic retarder. We discuss the spatial resolution of the sensor and experimentally reconstruct a wavefront modulated by a pattern. Then we obtain the Zernike coefficients with three different wavelengths before and after modulation. Our work makes this new wavefront sensor more applicable to actual tasks like biomedical imaging.