Quantitative dynamic phase mapping via single-arm field-correlation ghost imaging

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. By mapping spatial information into the temporal domain, this single-pixel architecture utilizes high-speed digitization to continuously resolve 2D phase dynamics, overcoming 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 closely match theoretical dispersion models, exhibiting a strong linear correlation between the retrieved phase shift and local sound pressure levels. This deterministic methodology provides a real-time metrological tool for characterizing rapidly evolving phenomena, including transient aeroacoustic flows, shockwaves, and microfluidic biological dynamics.