Measurement of degenerate orbital angular momentum qubits by stimulated emission tomography

Measurement of degenerate orbital angular momentum qubits by stimulated emission tomography | 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 Measurement of degenerate orbital angular momentum qubits by stimulated emission tomography Seonghu Jung, Do-Kyeong Ko This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7994325/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Orbital angular momentum (OAM) of light has acquired interest of scientists due to its novel properties. Feasible high dimensional Hilbert space and high dimensional entanglement that OAM offers made it a valuable DOF for many quantum optical protocols. However, conventional measurement of OAM state which exploits coincidence count based quantum state tomography (QST) requires accumulation of data which makes the process time-consuming which is a serious obstacle especially for high dimensional OAM qudits. In this work, we suggest stimulated emission tomography (SET) as a solution for prompt measurement of OAM entangled photons. We show that SET can successfully extract information of SPDC photons by measuring spiral bandwidth and reconstructing the density matrix of SPDC photons. The fidelity and linear entropy of the reconstructed density matrix is \(\:0.91\pm\:0.01\) and \(\:0.12\pm\:0.01\), respectively, while the time required for each projective measurement is 1s. Our results show the potential of SET to streamline the repetitive but necessary tomographic process. Physical sciences/Optics and photonics Physical sciences/Physics Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 23 Mar, 2026 Reviews received at journal 13 Mar, 2026 Reviewers agreed at journal 09 Mar, 2026 Editor invited by journal 06 Feb, 2026 Reviews received at journal 10 Dec, 2025 Reviewers agreed at journal 19 Nov, 2025 Reviewers invited by journal 18 Nov, 2025 Editor assigned by journal 03 Nov, 2025 Submission checks completed at journal 03 Nov, 2025 First submitted to journal 31 Oct, 2025 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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