Align-Free Multi-Plane Phase Retrieval

TL;DR

This paper introduces an adaptive, alignment-free multi-plane phase retrieval method that digitally corrects misalignments, simplifying setup and reducing costs, validated through simulations and experiments.

Contribution

The novel ACC strategy enables alignment-free phase retrieval by on-the-fly feature detection and transformation calculation, eliminating hardware complexity.

Findings

Successfully corrects misalignments digitally

Reduces hardware complexity and cost

Validated through simulations and experiments

Abstract

The multi-plane phase retrieval method provides a budget-friendly and effective way to perform phase imaging, yet it often encounters alignment challenges due to shifts along the optical axis in experiments. Traditional methods, such as employing beamsplitters instead of mechanical stage movements or adjusting focus using tunable light sources, add complexity to the setup required for multi-plane phase retrieval. Attempts to address these issues computationally face difficulties due to the variable impact of diffraction, which renders conventional homography techniques inadequate. In our research, we introduce a novel Adaptive Cascade Calibrated (ACC) strategy for multi-plane phase retrieval that overcomes misalignment issues. This technique detects feature points within the refocused sample space and calculates the transformation matrix for neighboring planes on-the-fly to digitally adjust measurements, facilitating alignment-free multi-plane phase retrieval. This approach not only avoids the need for complex and expensive optical hardware but also simplifies the imaging setup, reducing overall costs. The effectiveness of our method is validated through simulations and real-world optical experiments.