{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T13:26:42Z","timestamp":1789133202182,"version":"build-2803163510"},"reference-count":42,"publisher":"Optica Publishing Group","issue":"6","license":[{"start":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T00:00:00Z","timestamp":1773705600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/doi.org\/10.1364\/OA_License_v2#VOR-OA"},{"start":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T00:00:00Z","timestamp":1773705600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/opg.optica.org\/policies\/opg-tdm-policy.json"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["62105061"],"award-info":[{"award-number":["62105061"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"},{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["12374301"],"award-info":[{"award-number":["12374301"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"},{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"name":"National Key Research and Development Program of China","award":["2024YFA1210500"],"award-info":[{"award-number":["2024YFA1210500"]}]},{"DOI":"10.13039\/501100019317","name":"Key Lab of Modern Optical Technologies of Education Ministry of China","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100019317","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Jiangsu Provincial Frontier Technology Research and Development Program","award":["BF2025065"],"award-info":[{"award-number":["BF2025065"]}]}],"content-domain":{"domain":["opg.optica.org"],"crossmark-restriction":false},"short-container-title":["Opt. Express"],"published-print":{"date-parts":[[2026,3,23]]},"abstract":"<jats:p>\n                    The scalability of integrated photonic systems for next-generation datacom and sensing applications is fundamentally limited by the strong polarization dependence of high-confinement waveguides. While silicon nitride (Si\n                    <jats:sub>3<\/jats:sub>\n                    N\n                    <jats:sub>4<\/jats:sub>\n                    ) has emerged as a premier platform for low-loss, broadband passive functionalities, mitigating polarization sensitivity typically requires complex polarization diversity schemes that increase footprint and insertion loss. We demonstrate a monolithic, polarization-insensitive Si\n                    <jats:sub>3<\/jats:sub>\n                    N\n                    <jats:sub>4<\/jats:sub>\n                    platform that eliminates the need for polarization splitters or rotators by engineering the waveguide geometry to suppress birefringence at the fundamental mode level. By utilizing a near-square cross-section (800\u2005nm\u2009\u00d7\u2009800\u2005nm), we achieve nearly identical effective and group indices for TE and TM modes across a broad spectral range. Leveraging this platform, we present two key devices: a broadband 1\u2009\u00d7\u20092 optical switch and a 1\u2009\u00d7\u20094 coarse wavelength division multiplexing (CWDM) demultiplexer. The optical switch operates across the C and L bands (1500\u20131620\u2005nm) with insertion losses below 1.52\u2005dB and polarization-dependent losses (PDL) below 1.53\u2005dB. The CWDM device exhibits superior performance with insertion losses below 1.14\u2005dB and PDL below 0.75\u2005dB. This approach offers a robust, low-complexity pathway for polarization-agnostic photonic processing in high-capacity optical networks.\n                  <\/jats:p>","DOI":"10.1364\/oe.586171","type":"journal-article","created":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T09:00:06Z","timestamp":1773133206000},"page":"10854","update-policy":"https:\/\/doi.org\/10.1364\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Monolithic low-birefringence silicon nitride platform for polarization-insensitive photonic integrated circuits"],"prefix":"10.1364","volume":"34","author":[{"given":"Zhengyu","family":"Guo","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04ct4d772","id-type":"ROR","asserted-by":"publisher"}]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liu","family":"Li","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haoran","family":"Wang","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Deng","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Fan","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sitong","family":"Liu","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8391-3208","authenticated-orcid":true,"given":"Shihua","family":"Chen","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruohu","family":"Zhang","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junpeng","family":"Lu","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6316-2256","authenticated-orcid":true,"given":"Zhenhua","family":"Ni","sequence":"additional","affiliation":[{"name":"Southeast University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7186-7045","authenticated-orcid":true,"given":"Tong","family":"Lin","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04ct4d772","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Soochow University"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"285","published-online":{"date-parts":[[2026,3,17]]},"reference":[{"key":"oe-34-6-10854-R1","doi-asserted-by":"publisher","first-page":"2301025","DOI":"10.1002\/lpor.202301025","type":"journal-article","volume":"18","author":"Zafar","year":"2024","journal-title":"Laser Photonics Rev."},{"key":"oe-34-6-10854-R2","doi-asserted-by":"publisher","first-page":"35","DOI":"10.1038\/s44310-024-00033-6","type":"journal-article","volume":"1","author":"Shahwar","year":"2024","journal-title":"npj Nanophotonics"},{"key":"oe-34-6-10854-R3","doi-asserted-by":"publisher","first-page":"469","DOI":"10.1364\/OL.36.000469","type":"journal-article","volume":"36","author":"Chen","year":"2011","journal-title":"Opt. 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