Reduction of Threshold Current in Deep-ultraviolet Laser Diodes With a Lattice-matched Waveguide Layer

Reduction of Threshold Current in Deep-ultraviolet Laser Diodes With a Lattice-matched Waveguide Layer | 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 Research Article Reduction of Threshold Current in Deep-ultraviolet Laser Diodes With a Lattice-matched Waveguide Layer Yongjie Zhou, Zhongqiu Xing, Fang Wang, Yuhuai Liu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8171835/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract The waveguide layer of deep-ultraviolet laser diodes (DUV LDs) can utilize the refractive index difference between itself and the active region material to confine light within the LD's resonant cavity and sustain laser oscillation. However, the injection current can diffuse laterally within the waveguide layer instead of being effectively confined to the active region. This lateral current spreading reduces the carrier density in the active region. Furthermore, defects or impurities in the waveguide layer can introduce non-radiative recombination centers, leading to additional carrier loss and a decrease in LD efficiency. Therefore, this study proposes a p -type waveguide layer ( p -WG) with a tapered AlN composition. This design introduces bulk polarization charges to mitigate the polarization electric field and achieves better lattice matching with the adjacent layers. It reduces carrier accumulation in the waveguide region, improves carrier transport, and promotes more efficient carrier injection into the quantum wells. Additionally, the tapered p -WG increases the refractive index near the active region. This enhances the optical confinement, reduces photon leakage, improves the optical confinement factor, and consequently lowers the threshold current of the LD. This study also compares the inverse tapered p -WG with the traditional p -WG structure. The threshold current of the structure is reduced to 203.4 mA, and the optical confinement factor is increased to 6.03%. Deep ultraviolet laser diode p-type waveguide threshold current carrier regulation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 10 Mar, 2026 Reviews received at journal 09 Mar, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers invited by journal 01 Dec, 2025 Editor assigned by journal 26 Nov, 2025 Submission checks completed at journal 26 Nov, 2025 First submitted to journal 21 Nov, 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8171835","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":553375886,"identity":"5b0308e2-ec98-4f82-b751-39d6c9aedd6a","order_by":0,"name":"Yongjie Zhou","email":"","orcid":"","institution":"Zhengzhou University of Industrial Technology","correspondingAuthor":false,"prefix":"","firstName":"Yongjie","middleName":"","lastName":"Zhou","suffix":""},{"id":553375887,"identity":"534d038d-4eca-4561-9ee2-4653a7adb258","order_by":1,"name":"Zhongqiu Xing","email":"","orcid":"","institution":"Zhengzhou Police 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Layer\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":false,"email":"","identity":"journal-of-russian-laser-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Journal of Russian Laser Research","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"VoR Journals","inReviewEnabled":false,"inReviewRevisionsEnabled":false},"keywords":"Deep ultraviolet laser diode, p-type waveguide, threshold current, carrier regulation","lastPublishedDoi":"10.21203/rs.3.rs-8171835/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8171835/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe waveguide layer of deep-ultraviolet laser diodes (DUV LDs) can utilize the refractive index difference between itself and the active region material to confine light within the LD's resonant cavity and sustain laser oscillation. However, the injection current can diffuse laterally within the waveguide layer instead of being effectively confined to the active region. This lateral current spreading reduces the carrier density in the active region. Furthermore, defects or impurities in the waveguide layer can introduce non-radiative recombination centers, leading to additional carrier loss and a decrease in LD efficiency. Therefore, this study proposes a \u003cem\u003ep\u003c/em\u003e-type waveguide layer (\u003cem\u003ep\u003c/em\u003e-WG) with a tapered AlN composition. This design introduces bulk polarization charges to mitigate the polarization electric field and achieves better lattice matching with the adjacent layers. It reduces carrier accumulation in the waveguide region, improves carrier transport, and promotes more efficient carrier injection into the quantum wells. Additionally, the tapered \u003cem\u003ep\u003c/em\u003e-WG increases the refractive index near the active region. This enhances the optical confinement, reduces photon leakage, improves the optical confinement factor, and consequently lowers the threshold current of the LD. This study also compares the inverse tapered \u003cem\u003ep\u003c/em\u003e-WG with the traditional \u003cem\u003ep\u003c/em\u003e-WG structure. The threshold current of the structure is reduced to 203.4 mA, and the optical confinement factor is increased to 6.03%.\u003c/p\u003e","manuscriptTitle":"Reduction of Threshold Current in Deep-ultraviolet Laser Diodes With a Lattice-matched Waveguide Layer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-04 11:16:36","doi":"10.21203/rs.3.rs-8171835/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-10T12:35:30+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-09T14:34:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"43680529649514319178703665126082527095","date":"2026-02-23T12:47:07+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-01T11:32:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-27T01:50:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-27T01:48:30+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Russian Laser Research","date":"2025-11-21T09:07:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":false,"email":"","identity":"journal-of-russian-laser-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Journal of Russian Laser Research","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"VoR Journals","inReviewEnabled":false,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"49a3213f-8ba1-46a4-ae21-22333161619c","owner":[],"postedDate":"December 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-03-30T18:39:54+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-04 11:16:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8171835","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8171835","identity":"rs-8171835","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}