High-fidelity holographic beam shaping with optimal transport and phase diversity

TL;DR

This paper introduces optimal transport-based algorithms to improve phase-only holographic beam shaping with SLMs, providing accurate initializations for phase retrieval and enabling phase and intensity measurement through phase diversity imaging.

Contribution

It presents a novel application of optimal transport methods for initializing phase retrieval in holographic beam shaping and extends these techniques to measure input beam properties.

Findings

Optimal transport methods serve as effective initializations for phase retrieval.

Algorithms enable accurate measurement of input beam phase and intensity.

Techniques improve efficiency and flexibility of holographic beam shaping.

Abstract

A phase-only spatial light modulator (SLM) provides a powerful way to shape laser beams into arbitrary intensity patterns, but at the cost of a hard computational problem of determining an appropriate SLM phase. Here we show that optimal transport methods can generate approximate solutions to this problem that serve as excellent initializations for iterative phase retrieval algorithms, yielding vortex-free solutions with superior accuracy and efficiency. Additionally, we show that analogous algorithms can be used to measure the intensity and phase of the input beam incident upon the SLM via phase diversity imaging. These techniques furnish flexible and convenient solutions to the computational challenges of beam shaping with an SLM.