Snapshot Broadband Coherent Diffraction Ultrafast Imaging

Abstract Recent studies have demonstrated that coherent diffraction imaging (CDI) can obtain the ultrafast intensity and phase information of an object with a snapshot, but it typically employs quasi‐monochromatic light for illumination. In this work, it presents a novel broadband coherent diffraction ultrafast imaging method, termed BCDUI, which enables simultaneous ultrafast intensity and phase imaging by decomposing and reconstructing broadband diffraction patterns with highly mixed wavelengths. In BCDUI, the spatiotemporal information of a dynamic scene is loaded onto a broadband illumination light with a temporally chirped laser pulse, then the broadband illumination light is recorded by a single‐shot hyperspectral imaging after encoding with spatial phase modulation, and the recorded diffraction image is finally decomposed into dozens of time‐resolved intensity and phase images with a temporal resolution of up to hundreds of femtoseconds. In the experiments, BCDUI is utilized to successfully observe the spatiotemporal evolution of the ultrafast intensity and phase information for the laser‐induced ablation on the glass surface and the optical Kerr effect in carbon disulfide, respectively. Given its powerful ability to detect the ultrafast intensity and phase information of an object, BCDUI will offer a well‐established tool for investigating the ultrafast dynamics of light‐matter interactions.