Quantum Ptychography: Single-Shot High-Resolution Imaging of 1-100 nm using Coherent EUV - X-ray Light with Quantum Properties

The extreme nonlinear upconversion process of high harmonic generation produces bright, fully coherent EUV and X-ray beams at 1-100 nm wavelengths. Numerous theoretical and experimental breakthroughs have led to exquisite attosecond control of various classical and quantum properties of the light - excelling what is possible for visible and infrared lasers. However, a full understanding of the limits of the quantum nonlinear interactions in high harmonic generation is still lacking. In academia and industry, tabletop EUV technology based on high harmonic generation is already addressing grand challenges in nanomaterials science and metrology. Specifically, EUV ptychography - a lensless imaging technique - has demonstrated high-fidelity phase characterization of the high harmonic light, as well as achieved near-diffraction-limited imaging of complex systems, reaching record near-wavelength 10-20 nm spatial resolution. However, ptychography’s scanning modality and use of long-wavelength EUV light limit the tabletop high-resolution real-time applications. In this project, we address fundamental physics questions and technological challenges by performing ptychography in novel quantum regimes of X-ray generation. First, ptychography can enable reconstruction of the quantum phase of harmonics which will allow to quantify strong correlations of electrons and attosecond dynamics in multiply-charged plasmas. Experimental access to the phase space paves a way to attosecond electron correlation spectroscopy and may result in brighter X-ray generation, possibly extending the emission into the multi-keV regime. Second, using state-of-the-art EUV – X-ray sources driven by UV lasers, we aim to overcome the 10 nm resolution barrier in 2D - 3D imaging and enhance the phase contrast using structured quantum light. Finally, non-scanning ptychography will be developed with drastic speed improvement for nanoimaging, biomedical microscopy, and advanced semiconductor metrology.