Quantitative Dynamic Phase Mapping via Single-Arm Field-Correlation Ghost Imaging

TL;DR

This paper introduces a single-arm optical system that uses ghost imaging and field correlation to perform real-time, quantitative 2D phase mapping of transparent media, overcoming traditional sensor limitations.

Contribution

It presents a novel single-arm, high-speed optical platform that directly maps 2D phase dynamics into the temporal domain for real-time analysis without frame-rate constraints.

Findings

Successfully reconstructs 2D acoustic pressure distributions.

Experimental validation matches theoretical dispersion models.

Demonstrates real-time phase mapping of dynamic phenomena.

Abstract

We demonstrate a single-arm optical platform for phase-retrieval-free, quantitative dynamic phase mapping of continuous transparent media via field-correlation ghost imaging. By modeling the medium as a dynamic pure-phase object, we spatially encode and compress its two-dimensional (2D) complex transmittance into a single bucket detector. Balanced heterodyne detection downconverts the optical frequencies for direct digitization. Crucially, by mapping spatial information into the temporal domain, this single-pixel architecture exploits high-speed digitization to continuously resolve 2D phase dynamics, effectively bypassing the frame-rate bottlenecks of traditional array sensors. Coupled with intermediate-frequency spectral analysis, this establishes a direct linear mapping from the recorded signal to the physical phase. The complex amplitude is thus deterministically extracted via field-correlation, enabling the spatial reconstruction of 2D acoustic pressure distributions using a pseudo-inverse algorithm. Experimental validations in an acoustic levitator confirm that the optically extracted acoustic wavelengths strictly match theoretical dispersion models, exhibiting a robust linear correlation between the retrieved phase shift and local sound pressure levels. This deterministic methodology provides a real-time-capable metrological tool for characterizing rapidly evolving phenomena, including transient aeroacoustic flows, shockwaves, and microfluidic biological dynamics.