Full-field Jones matrix measurement using in-line polarization terahertz digital holography

Jones matrices provide a complete description of the polarization response of anisotropic media. However, existing methods in the terahertz (THz) band struggle to balance the amplitude and phase information of the Jones matrix with imaging speed: time-domain spectroscopy enables reconstruction but relies on point-by-point scanning, while continuous-wave intensity imaging is fast but loses phase information. This Letter proposes an in-line polarization THz digital holography method for full-field Jones matrix measurement, which adopts a lensless Gabor geometry, four-state polarization encoding, and the total variation extrapolation phase retrieval algorithm. The accuracy of the proposed method is validated through experiments on isotropic, naturally anisotropic, and standard anisotropic samples. This work provides what we believe to be a novel approach for THz polarimetric characterization of anisotropic materials, featuring a compact optical layout, low propagation loss, and efficient bandwidth utilization.