Optimised optical waveforms drive efficient water window attosecond pulse generation

Optimised optical waveforms drive efficient water window attosecond pulse generation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Optimised optical waveforms drive efficient water window attosecond pulse generation Giulio Rossi, Miguel Silva Toledo, Fabian Scheiba, Maximilian Kubullek, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8722587/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract The ability to precisely tailor optical waveforms provides a powerful means of controlling strong-field interactions, including high-harmonic generation (HHG) for attosecond pulse production. Although numerous tailored waveforms have been proposed to extend the harmonic cut-off or enhance conversion efficiency, achieving such improvements in the soft X-ray region remains challenging because plasma formed in the medium can strongly distort the driving field during propagation. Moreover, isolated attosecond pulse (IAP) generation demands sub-cycle waveform shaping to enhance a single attosecond burst while suppressing contributions from neighbouring optical cycles. Here, we demonstrate order-of-magnitude enhancements in IAP generation efficiency up to∼450 eV, by driving HHG in helium with tailored fields spanning the 0.7 - 2.2 μm range, surpassing a 1.5-cycle driver centred at 1.8 μm. Direct waveform measurement and simulations allow us to track the propagation of optimised optical transients through the nonlinear medium and to disentangle the intertwined microscopic and macroscopic contributions that govern soft X-ray HHG. These results establish sub-cycle waveform engineering as a robust strategy for optimising soft X-ray IAP generation and provide an experimentally validated framework for next-generation attosecond sources. Physical sciences/Optics and photonics/Optical physics/High-harmonic generation Physical sciences/Optics and photonics/Optical physics/X-rays Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryInformationOptimisedopticalwaveformsWWIAPs.pdf Supplementary Information Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8722587","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":585116588,"identity":"d9e665a9-4a42-410f-a2fc-8b73f5497b71","order_by":0,"name":"Giulio Rossi","email":"data:image/png;base64,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","orcid":"","institution":"DESY","correspondingAuthor":true,"prefix":"","firstName":"Giulio","middleName":"","lastName":"Rossi","suffix":""},{"id":585116589,"identity":"97806e01-39fc-495d-a19b-0bf3847f9880","order_by":1,"name":"Miguel Silva Toledo","email":"","orcid":"https://orcid.org/0000-0003-0672-5865","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Miguel","middleName":"Silva","lastName":"Toledo","suffix":""},{"id":585116590,"identity":"dde2ed54-461c-498d-9cf5-60dbf3e32c71","order_by":2,"name":"Fabian Scheiba","email":"","orcid":"","institution":"Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY","correspondingAuthor":false,"prefix":"","firstName":"Fabian","middleName":"","lastName":"Scheiba","suffix":""},{"id":585116591,"identity":"939b4334-cb2c-42a8-b31e-a73a88a7f754","order_by":3,"name":"Maximilian Kubullek","email":"","orcid":"","institution":"Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY","correspondingAuthor":false,"prefix":"","firstName":"Maximilian","middleName":"","lastName":"Kubullek","suffix":""},{"id":585116592,"identity":"cffbecf5-1cdc-4a3e-b206-7f1d56c07196","order_by":4,"name":"Rafael de Q. 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