{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T05:12:11Z","timestamp":1784956331906,"version":"3.55.0"},"reference-count":33,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T00:00:00Z","timestamp":1777075200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T00:00:00Z","timestamp":1777075200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Nanophotonics"],"published-print":{"date-parts":[[2026,5,13]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Compact, high\u2010efficiency chiral light sources are essential for on\u2010chip integrated photonics, yet simultaneously achieving giant circular dichroism (CD), ultrahigh quality factor (Q), and angular robustness remains unresolved. Here, we report a chiral flat\u2010band metasurface that unifies giant CD, ultrahigh Q, and full angular resilience by merging symmetry\u2010broken bound states in the continuum (BICs) with a dispersion\u2010engineered photonic band. Platform\u2010tilted double rectangular nanopillars break both in\u2010plane and out\u2010of\u2010plane mirror symmetries, generating an intrinsical chirality and an ultraflat photonic band. The resulting quasi\u2010BIC resonance features a high Q\u2010value \u2248 1969 and near\u2010unity transmission CD (&gt;\u00a00.99). Crucially, the dispersionless ultraflat band ensures stable resonance and maintains high CD across a moderate angular range of\u00a0\u00b1\u00a04\u00b0. Furthermore, strong slow light field confinement effectively quenches lateral leakage, enabling high ellipticity (\n                    <jats:italic>\u03c1<\/jats:italic>\n                    \u00a0&gt;\u00a00.99) and\n                    <jats:italic>Q<\/jats:italic>\n                    \u2248 1108 even in finite\u2010sized structures of merely eight periods. By synergistic integrating giant chiral response with flat\u2010band photonics, this strategy establishes a scalable route to ultralow threshold\u2013integrated chiral photonic\u2010crystal surface\u2010emitting lasers (PCSELs) and angle robust chiral sensors. Compared with existing chiral flat\u2010band structures, our design achieves substantial, concurrent enhancement of circular dichroism and a quality factor, establishing a compelling platform for integrated chiral photonic devices.\n                  <\/jats:p>","DOI":"10.1002\/nap2.70106","type":"journal-article","created":{"date-parts":[[2026,4,25]],"date-time":"2026-04-25T09:45:36Z","timestamp":1777110336000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Giant Circular Dichroism in Chiral Broad Flat\u2010Band Quasi\u2010BIC Metasurface"],"prefix":"10.1002","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-8656-4803","authenticated-orcid":false,"given":"Chunhao","family":"Xu","sequence":"first","affiliation":[{"name":"Institute of Semiconductors Chinese Academy of Sciences  Beijing China"},{"name":"College of Materials Science and Opto\u2010Electronic Technology University of Chinese Academy of Sciences  Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jietao","family":"Liu","sequence":"additional","affiliation":[{"name":"Institute of Intelligent Photonics Nankai University  Tianjin China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guofeng","family":"Song","sequence":"additional","affiliation":[{"name":"Institute of Semiconductors Chinese Academy of Sciences  Beijing China"},{"name":"College of Materials Science and Opto\u2010Electronic Technology University of Chinese Academy of Sciences  Beijing China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,4,25]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.abq7870"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1364\/oe.26.017841"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1088\/0034\u20104885\/79\/7\/076401"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1021\/acs.nanolett.0c03575"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1515\/nanoph\u20102024\u20100626"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1515\/nanoph\u20102025\u20100357"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1515\/nanoph\u20102025\u20100019"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.104.163901"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1038\/natrevmats.2016.48"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.3788\/pi.2024.R01"},{"key":"e_1_2_8_12_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.125.053902"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1515\/nanoph\u20102024\u20100666"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/adom.202101162"},{"key":"e_1_2_8_15_1","doi-asserted-by":"publisher","DOI":"10.1364\/ol.462021"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/andp.202200263"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.126.073001"},{"key":"e_1_2_8_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/andp.202100255"},{"key":"e_1_2_8_19_1","doi-asserted-by":"publisher","DOI":"10.1364\/oe.25.006104"},{"key":"e_1_2_8_20_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41586\u2010022\u201005467\u20106"},{"key":"e_1_2_8_21_1","doi-asserted-by":"publisher","DOI":"10.3390\/nano14171405"},{"key":"e_1_2_8_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.optlastec.2023.110531"},{"key":"e_1_2_8_23_1","doi-asserted-by":"publisher","DOI":"10.1364\/ol.559650"},{"key":"e_1_2_8_24_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.newton.2025.100057"},{"key":"e_1_2_8_25_1","doi-asserted-by":"publisher","DOI":"10.1021\/acsnano.5c01972"},{"key":"e_1_2_8_26_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41566\u2010025\u201001665\u20106"},{"key":"e_1_2_8_27_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467\u2010025\u201065860\u20103"},{"key":"e_1_2_8_28_1","doi-asserted-by":"publisher","DOI":"10.1021\/acsphotonics.4c02332"},{"key":"e_1_2_8_29_1","doi-asserted-by":"publisher","DOI":"10.1364\/OPTICA.498089"},{"key":"e_1_2_8_30_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.134.103801"},{"key":"e_1_2_8_31_1","doi-asserted-by":"publisher","DOI":"10.1007\/s13538\u2010025\u201001804\u2010y"},{"key":"e_1_2_8_32_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.132.173802"},{"key":"e_1_2_8_33_1","doi-asserted-by":"publisher","DOI":"10.1002\/apxr.202500214"},{"key":"e_1_2_8_34_1","doi-asserted-by":"publisher","DOI":"10.1002\/lpor.202501247"}],"container-title":["Nanophotonics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/nap2.70106","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/nap2.70106","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/nap2.70106","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T13:05:40Z","timestamp":1778850340000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/nap2.70106"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,25]]},"references-count":33,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2026,5,13]]}},"alternative-id":["10.1002\/nap2.70106"],"URL":"https:\/\/doi.org\/10.1002\/nap2.70106","archive":["Portico"],"relation":{},"ISSN":["2192-8614","2192-8614"],"issn-type":[{"value":"2192-8614","type":"print"},{"value":"2192-8614","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,25]]},"assertion":[{"value":"2026-01-29","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-04-07","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-04-25","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70106"}}