Single-shot TIE using polarization multiplexing (STIEP) for quantitative phase imaging

Transport of intensity equation (TIE) is a promising technique for quantitative phase imaging (QPI). Usually, in TIE, two axially defocused intensity distributions are used to recover the phase, which requires the mechanical shift of either the image sensor or tested sample along the optical axis. This paper presents a new method for QPI based on single-shot TIE using polarization multiplexing. The two defocused intensity distributions are recorded simultaneously on a single camera plane. For that, a diffractive optical element is positioned at the Fourier plane of the sample to split the incoming wavefront into two orthogonally polarized wavefronts. These multiplexed wavefronts will result in two axially and symmetrically defocused intensities on the camera plane. Furthermore, the technique is well-suited for both static and dynamic phase measurements, including that of biological samples (e.g., red blood cells). The feasibility of the proposed method is demonstrated with experimental results.