Transformation optics based ultra-compact high-Q micro-ring-resonator with high-precision locking

Transformation optics based ultra-compact high-Q micro-ring-resonator with high-precision locking | 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 Transformation optics based ultra-compact high-Q micro-ring-resonator with high-precision locking Yuan Yu, shuai cui, Zhao Pan, Jiayao Su, Lifeng Cai, Dingshan Gao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6876000/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Achieving ultra-low propagation loss in optical waveguides is essential for enhancing micro-resonator quality factors and enabling large-scale photonic integration. Despite efforts to minimize scattering loss with multimode waveguides, bending radii remain large due to waveguide dimensions. We present an innovative method that combines multimode waveguides with a transformation optics (TO)-based mode converter to achieve ultra-low loss and exceptional bending characteristics in silicon-based multimode micro-ring resonators (MRRs). Our results demonstrate an unprecedented bending radius of just 10 µm for 2-µm-wide waveguides, alongside an intrinsic quality factor (Qᵢ) of (1.13 ± 0.15) × 10⁷ and ultra-low propagation loss of 5.8 ± 0.33 dB/m, a 26-fold reduction compared to conventional waveguides. Additionally, we propose a novel high-precision MRR wavelength locking method based on an optoelectronic oscillator (OEO), achieving a two-order-of-magnitude improvement in resonant wavelength stabilization. These advancements redefine the performance-density trade-off for MRRs, enabling scalable, ultra-dense photonic integration. Our work opens new possibilities for applications in microwave photonics, nonlinear photonics, large-scale integration, and quantum technologies, offering a versatile design framework for ultrahigh-Q multimode MRRs. Physical sciences/Optics and photonics/Applied optics/Integrated optics Physical sciences/Optics and photonics/Applied optics/Microwave photonics Full Text Additional Declarations There is no conflict of interest Supplementary Files SupplementaryInformation.pdf Transformation optics based ultra-compact high-Q micro-ring-resonator with high-precision locking Cite Share Download PDF Status: Posted 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-6876000","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":475943273,"identity":"492b4e2e-c7da-405f-86ad-0d62b80fcf1e","order_by":0,"name":"Yuan 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