Experimental Validation of Double-Blind Fourier Holography in an HWO-Like Segmented Aperture

Double-Blind Fourier Holography (DBFH) is a phase-retrieval method that has been shown numerically to address wavefront-sensing challenges for future segmented-aperture space telescopes, including the Habitable Worlds Observatory (HWO). DBFH uses a set of carefully selected pupil-plane amplitude masks and their corresponding focal-plane intensity measurements to construct an algebraically linear inverse problem, enabling computationally efficient and stable reconstruction of the complex pupil field. Here, we present the first experimental demonstration of DBFH using a spatial light modulator and an HWO EAC5-like segmented-aperture geometry. We reconstruct challenging pseudo-random wavefronts and compare DBFH with the established Focus-Diverse Phase Retrieval (FDPR) method. The two methods achieve comparable reconstruction precision, while exhibiting distinct strengths and limitations. We further demonstrate DBFH wavefront sensing in the presence of a binary source, a scenario that is not naturally accommodated by conventional FDPR. These results provide experimental proof of concept and establish technology readiness level 3 for DBFH as a wavefront-sensing method for space telescopes with segmented primary mirrors.