Generalized Zernike Phase-Contrast Imaging

TL;DR

This paper demonstrates that Zernike phase-contrast imaging can nearly reach the quantum limit even with practical limitations like finite beam width and phase plate cutoff, and extends its applicability to various incident beams.

Contribution

It shows the robustness of Zernike phase-contrast imaging in realistic conditions and proposes its use with different incident beams such as speckle beams.

Findings

Achieves over 95% of the quantum Fisher information limit with finite beam and phase plate.

Applicable to any incident beam, including speckle beams.

Potential for practical implementation in quantum-limited imaging.

Abstract

Zernike phase-contrast imaging is unique among imaging techniques in that it enables the upper limit of Fisher information allowed by quantum mechanics. Here we show that, in a departure from an ideal setting, using an incident beam of finite width, and a $\pi/2$ phase plate having a finite cutoff, the technique can still deliver $>95\%$ of the quantum limit. We point out that the Zernike method is, in principle, applicable to any incident beam. As an example, we sketch an approximate implementation of the method for an incident speckle beam, and show that it too can deliver $>95\%$ of the quantum limit.