Single-axis scanning coherent diffractive imaging for spectroscopic and wavefront retrieval.

We present single-axis scanning coherent diffractive imaging (AS-CDI), in which the detector remains fixed while the sample is translated along the optical axis through a spatially evolving probe. The axial evolution of the illumination provides additional redundancy for wavelength-resolved joint reconstruction of the object and the probe from a single scan. We validate the concept by simultaneous spectroscopic imaging and quantitative characterization of the illumination wavefront, from which the chromatic aberration of a broadband field is accurately measured. This capability establishes AS-CDI as a versatile tool for multi-modal imaging and reference-free wavefront and dispersion metrology, with immediate potential in ultrafast science, material characterization, and live-cell bio-imaging.