EUV Microscopy with a Tabletop High Harmonic Generation Source: Generalizing Coherent Di ractive Imaging to Extended Samples in Transmission, Reflection, and Hyperspectral Modalities

<p>Imaging at the nanoscale is of great interest for applications in materials science, nanoscience\&nbsp;<span style="line-height: 1.6em;">and biology. The microscopy method developed in this thesis combines a tabletop coherent EUV/Xray\&nbsp;</span><span style="line-height: 1.6em;">source based on high harmonic generation, and an image-forming method based on coherent\&nbsp;</span><span style="line-height: 1.6em;">diffractive imaging. This microscopy method offers truly diffraction-limited resolution; however,\&nbsp;</span><span style="line-height: 1.6em;">previous work has been limited to thin, isolated samples in transmission mode. This thesis work\&nbsp;</span><span style="line-height: 1.6em;">extends this tool for imaging non-isolated samples, and for working in refl</span><span style="line-height: 1.6em;">ection mode to image\&nbsp;</span><span style="line-height: 1.6em;">surface features of thick samples. The quantitative phase information of the refl</span><span style="line-height: 1.6em;">ection image enables\&nbsp;</span><span style="line-height: 1.6em;">surface prolometry capability with sub-nanometer precision. The microscope developed in this\&nbsp;</span><span style="line-height: 1.6em;">work is also demonstrated to have hyperspectral capability with simultaneous multi-wavelength\&nbsp;</span><span style="line-height: 1.6em;">illumination, without the need for wavelength scanning or energy-resolved detectors. In the future,\&nbsp;</span><span style="line-height: 1.6em;">by taking advantage of the short-pulse nature of the high harmonic illumination, this microscope will\&nbsp;</span><span style="line-height: 1.6em;">be able to image nanoscale ultrafast dynamics with 10 femtosecond temporal resolution, opening</span><span style="line-height: 1.6em;">the door for imaging at the space-time limits.</span></p>