The Observation of Transient Thin Film Structures During the Femto-Second Laser Ablation Process by Using the Soft X-Ray Laser Probe

We modified a soft x-ray laser (SXRL) interferometer synchronized with a Ti:sapphire laser to observe a single-shot image of the nano-scale structure dynamics of materials induced by an optical laser pulse. The lateral resolution on the sample surface was improved to 0.7 μm by using precise imaging optics. Using this system, we succeeded in observing thin film structures above the solid (or liquid) surface in the femtosecond laser ablation process of metals (Au). The thin film worked as soft x-ray beam splitter. This result shows a thin film was smooth and dense (with a roughness of a few nanometers and near sold density). Furthermore, it gave rise to the possibility of generating novel transient soft x-ray optics