Design and Optimization of Polymer-Based 2×4 MMI Splitters for Photonic Integrated Circuits

Design and Optimization of Polymer-Based 2×4 MMI Splitters for Photonic Integrated Circuits | 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 Design and Optimization of Polymer-Based 2×4 MMI Splitters for Photonic Integrated Circuits Nazmus Shakib Lalin, Zarin Tasnim Nijhum, Miss Nourin Nurain Amina, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8827838/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 Polymer-based photonic integrated circuits are promising for board-level optical interconnects due to their low-cost fabrication, mechanical flexibility, and compatibility with large-area processing; however, efficient multi-input power routing using passive components remains challenging. In this work, we present the design, simulation, and optimization of a step-index polymer 2×4 multimode interference (MMI) splitter operating at 1550 nm, targeting compact dual-input power distribution for board-level photonics. The device is realized on the SUNCONNECT organic–inorganic hybrid polymer platform using NP001L2 (n = 1.573) as the core and NP216 (n = 1.560) as the cladding, and analyzed using the beam propagation method (BPM) in RSoft BeamPROP. Starting from self-imaging theory, the multimode-section width and length, access-waveguide width, input separation, taper geometry, and nonuniform output-port spacing are systematically optimized through staged parameter sweeps to recover stable self-imaging under dual-input excitation. The optimized splitter achieves near-symmetric four-way power distribution with output power splitting ratios of 24.59%, 24.39%, 25.00%, and 26.02%. The corresponding excess loss is 6.13 dB (TE) and 6.18 dB (TM), with a low polarization-dependent loss of 0.04 dB, indicating robust polarization behavior despite increased modal complexity. The results reveal that input parity control, width-driven mode expansion, and asymmetric port placement are critical design levers for dual-input polymer MMIs. This study provides a practical optimization framework for polymer-based multi-source MMI splitters and highlights the key limitations that must be addressed for low-loss scalable board-level optical interconnects. Photonics/optics Computational Physics Polymer photonics multimode interference (MMI) splitter 2×4 power splitter beam propagation method (BPM) board-level optical interconnects step-index waveguide power splitting ratio (PSR) excess loss. Full Text Additional Declarations The authors declare no competing interests. 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. 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-8827838","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":588123464,"identity":"a18038fa-b0e5-4469-982d-df1a71b351be","order_by":0,"name":"Nazmus Shakib Lalin","email":"data:image/png;base64,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","orcid":"https://orcid.org/0009-0002-5460-0506","institution":"Physics Discipline, Khulna University, Khulna-9208, Bangladesh","correspondingAuthor":true,"prefix":"","firstName":"Nazmus","middleName":"Shakib","lastName":"Lalin","suffix":""},{"id":588123467,"identity":"85af4e3b-cc1d-4014-95c6-da338b093843","order_by":1,"name":"Zarin Tasnim Nijhum","email":"","orcid":"","institution":"Physics Discipline, Khulna University, Khulna-9208, Bangladesh","correspondingAuthor":false,"prefix":"","firstName":"Zarin","middleName":"Tasnim","lastName":"Nijhum","suffix":""},{"id":588123468,"identity":"323b6aeb-596d-4b16-a481-913f97a9263e","order_by":2,"name":"Miss Nourin Nurain Amina","email":"","orcid":"","institution":"Physics Discipline, Khulna University, Khulna-9208, Bangladesh","correspondingAuthor":false,"prefix":"","firstName":"Miss","middleName":"Nourin Nurain","lastName":"Amina","suffix":""},{"id":588123470,"identity":"af0dfbe7-4a5c-4569-8b0d-5bba582e8918","order_by":3,"name":"Shirazum Monira","email":"","orcid":"","institution":"Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh","correspondingAuthor":false,"prefix":"","firstName":"Shirazum","middleName":"","lastName":"Monira","suffix":""},{"id":588123469,"identity":"05b338f3-7de8-4237-915f-a9196a91e85f","order_by":4,"name":"Tonmoy Malakar","email":"","orcid":"","institution":"Department of Electrical and Computer Engineering, The University of Oklahoma, Norman, OK, USA","correspondingAuthor":false,"prefix":"","firstName":"Tonmoy","middleName":"","lastName":"Malakar","suffix":""},{"id":588123465,"identity":"9b062bd1-c7fe-4f2a-b768-08124813ad17","order_by":5,"name":"Md Omar Faruk Rasel","email":"","orcid":"https://orcid.org/0000-0002-5729-6426","institution":"Physics Discipline, Khulna University, Khulna-9208, Bangladesh","correspondingAuthor":false,"prefix":"","firstName":"Md","middleName":"Omar Faruk","lastName":"Rasel","suffix":""},{"id":588123466,"identity":"5bbac7e8-1813-4f1a-a2cd-8250f612e9d4","order_by":6,"name":"Md. 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In this work, we present the design, simulation, and optimization of a step-index polymer 2×4 multimode interference (MMI) splitter operating at 1550 nm, targeting compact dual-input power distribution for board-level photonics. The device is realized on the SUNCONNECT organic–inorganic hybrid polymer platform using NP001L2 (n = 1.573) as the core and NP216 (n = 1.560) as the cladding, and analyzed using the beam propagation method (BPM) in RSoft BeamPROP. Starting from self-imaging theory, the multimode-section width and length, access-waveguide width, input separation, taper geometry, and nonuniform output-port spacing are systematically optimized through staged parameter sweeps to recover stable self-imaging under dual-input excitation. The optimized splitter achieves near-symmetric four-way power distribution with output power splitting ratios of 24.59%, 24.39%, 25.00%, and 26.02%. 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