Demonstration of a dual-beam zone plate for phase-contrast coherent soft x-ray imaging

Coherent x-ray imaging faces fundamental speed limitations due to computational reconstruction requirements of current phase retrieval methods. We demonstrate dual-beam zone plates that enable direct phase-contrast measurements by structuring coherent x-rays into two focused 110nm spots separated by 11μm, bypassing iterative algorithms entirely. Experimental validation at the COSMIC beamline confirms precise dual-beam formation with clear interference patterns analogous to Young’s double-slit experiment. Comparative measurements reveal enhanced sensitivity: phase detection achieves 45° phase shifts at sample boundaries where intensity contrast shows poor signal clarity due to noise. Spectroscopic demonstrations across the oxygen K-edge show energy-selective capabilities, with phase features providing improved signal-to-noise ratio compared to conventional absorption measurements. The high photon efficiency of this direct measurement approach enables fast imaging capabilities, making the technique well-suited for studying dynamic processes in quantum materials with next-generation synchrotron sources.