{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2024:IZRIH4RWCMQTCIELBFBLM4D24X","short_pith_number":"pith:IZRIH4RW","canonical_record":{"source":{"id":"2404.06117","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2024-04-09T08:40:08Z","cross_cats_sorted":[],"title_canon_sha256":"36c589a86f2755680ba939f5222147b024b9255b415c2c4f2da43024f5cd37bd","abstract_canon_sha256":"f4f04fc6a38126549332d807c4e6b606d314cfa76cf67fdf5488b2fa8b2095d7"},"schema_version":"1.0"},"canonical_sha256":"466283f236132131208b0942b6707ae5fb3f5c66f9536d4a52038ac1db1988a2","source":{"kind":"arxiv","id":"2404.06117","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2404.06117","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"arxiv_version","alias_value":"2404.06117v1","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2404.06117","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_12","alias_value":"IZRIH4RWCMQT","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_16","alias_value":"IZRIH4RWCMQTCIEL","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_8","alias_value":"IZRIH4RW","created_at":"2026-07-05T08:06:04Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2024:IZRIH4RWCMQTCIELBFBLM4D24X","target":"record","payload":{"canonical_record":{"source":{"id":"2404.06117","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2024-04-09T08:40:08Z","cross_cats_sorted":[],"title_canon_sha256":"36c589a86f2755680ba939f5222147b024b9255b415c2c4f2da43024f5cd37bd","abstract_canon_sha256":"f4f04fc6a38126549332d807c4e6b606d314cfa76cf67fdf5488b2fa8b2095d7"},"schema_version":"1.0"},"canonical_sha256":"466283f236132131208b0942b6707ae5fb3f5c66f9536d4a52038ac1db1988a2","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T08:06:04.432150Z","signature_b64":"zsI434/oD/7rDPVZybVFAHMgvZTgEPWVxsr2V1SvYeghoiBfF0mek8mej6vQsaBTwsMvH5a0NYv0SWZL1FSVBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"466283f236132131208b0942b6707ae5fb3f5c66f9536d4a52038ac1db1988a2","last_reissued_at":"2026-07-05T08:06:04.431672Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T08:06:04.431672Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2404.06117","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T08:06:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/VKXfSV4C5Vub1q4rv8b5ib85pmoI7Gz4AraQAHNDHSdd0ZkJOpgzPbtOK1cYYe9r564++wurYcrvFjWs7XeAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T03:57:03.460303Z"},"content_sha256":"5f4fea5421665e0a350d4ebcc8ffec5b434e3fe5b65e55d1bc9a5b3a598c88bd","schema_version":"1.0","event_id":"sha256:5f4fea5421665e0a350d4ebcc8ffec5b434e3fe5b65e55d1bc9a5b3a598c88bd"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2024:IZRIH4RWCMQTCIELBFBLM4D24X","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Low-Loss Silicon Directional Coupler with Arbitrary Coupling Ratios for Broadband Wavelength Operation Based on Bent Waveguides","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":[],"primary_cat":"physics.optics","authors_text":"Ahmed H. El-Saeed, Alaa Elshazly, Chiara Marchese, Dieter Bode, Dimitrios Velenis, Filippo Ferraro, Guy Lepage, Hakim Kobbi, Javad Rahimi Vaskasi, Joris Van Campenhout, Marko Ersek Filipcic, Maumita Chakrabarti, Peter De Heyn, Peter Verheyen, Philippe Absil, Qingzhong Deng, Rafal Magdziak, Swetanshu Bipul, Wim Bogaerts, Yoojin Ban","submitted_at":"2024-04-09T08:40:08Z","abstract_excerpt":"We demonstrate a design for a high-performance $2 \\times 2$ splitter meeting the essential requirements of broadband coupling, support for arbitrary coupling ratio, ultra low-loss, high fabrication tolerance, and a compact footprint.\n  This is achieved based on a rigorous coupled mode theory analysis of the broadband response of the bent directional coupler (DC) and by demonstrating a full coupling model, with measured broadband values of 0.4, 0.5, 0.6, and 0.7.\n  As a benchmark, we demonstrate a 0.5:0.5 splitter that significantly reduces coupling variation from 0.391 in the traditional DC to"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2404.06117","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2404.06117/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T08:06:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"50LO2G8BFi6bvswypgkZVQuC3ky1mW4lgrjlMNxUWcicZ0uffJKQVXyiXhIVZxlmjJgAA3uOiDmqwVMnductDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-04T03:57:03.460812Z"},"content_sha256":"f93135ff9a26954f43d22017ba67f5dc876307173b9296a0b872a7c1340f3eaa","schema_version":"1.0","event_id":"sha256:f93135ff9a26954f43d22017ba67f5dc876307173b9296a0b872a7c1340f3eaa"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/IZRIH4RWCMQTCIELBFBLM4D24X/bundle.json","state_url":"https://pith.science/pith/IZRIH4RWCMQTCIELBFBLM4D24X/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/IZRIH4RWCMQTCIELBFBLM4D24X/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-08-04T03:57:03Z","links":{"resolver":"https://pith.science/pith/IZRIH4RWCMQTCIELBFBLM4D24X","bundle":"https://pith.science/pith/IZRIH4RWCMQTCIELBFBLM4D24X/bundle.json","state":"https://pith.science/pith/IZRIH4RWCMQTCIELBFBLM4D24X/state.json","well_known_bundle":"https://pith.science/.well-known/pith/IZRIH4RWCMQTCIELBFBLM4D24X/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2024:IZRIH4RWCMQTCIELBFBLM4D24X","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"f4f04fc6a38126549332d807c4e6b606d314cfa76cf67fdf5488b2fa8b2095d7","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2024-04-09T08:40:08Z","title_canon_sha256":"36c589a86f2755680ba939f5222147b024b9255b415c2c4f2da43024f5cd37bd"},"schema_version":"1.0","source":{"id":"2404.06117","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2404.06117","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"arxiv_version","alias_value":"2404.06117v1","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2404.06117","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_12","alias_value":"IZRIH4RWCMQT","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_16","alias_value":"IZRIH4RWCMQTCIEL","created_at":"2026-07-05T08:06:04Z"},{"alias_kind":"pith_short_8","alias_value":"IZRIH4RW","created_at":"2026-07-05T08:06:04Z"}],"graph_snapshots":[{"event_id":"sha256:f93135ff9a26954f43d22017ba67f5dc876307173b9296a0b872a7c1340f3eaa","target":"graph","created_at":"2026-07-05T08:06:04Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2404.06117/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We demonstrate a design for a high-performance $2 \\times 2$ splitter meeting the essential requirements of broadband coupling, support for arbitrary coupling ratio, ultra low-loss, high fabrication tolerance, and a compact footprint.\n  This is achieved based on a rigorous coupled mode theory analysis of the broadband response of the bent directional coupler (DC) and by demonstrating a full coupling model, with measured broadband values of 0.4, 0.5, 0.6, and 0.7.\n  As a benchmark, we demonstrate a 0.5:0.5 splitter that significantly reduces coupling variation from 0.391 in the traditional DC to","authors_text":"Ahmed H. El-Saeed, Alaa Elshazly, Chiara Marchese, Dieter Bode, Dimitrios Velenis, Filippo Ferraro, Guy Lepage, Hakim Kobbi, Javad Rahimi Vaskasi, Joris Van Campenhout, Marko Ersek Filipcic, Maumita Chakrabarti, Peter De Heyn, Peter Verheyen, Philippe Absil, Qingzhong Deng, Rafal Magdziak, Swetanshu Bipul, Wim Bogaerts, Yoojin Ban","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2024-04-09T08:40:08Z","title":"Low-Loss Silicon Directional Coupler with Arbitrary Coupling Ratios for Broadband Wavelength Operation Based on Bent Waveguides"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2404.06117","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:5f4fea5421665e0a350d4ebcc8ffec5b434e3fe5b65e55d1bc9a5b3a598c88bd","target":"record","created_at":"2026-07-05T08:06:04Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"f4f04fc6a38126549332d807c4e6b606d314cfa76cf67fdf5488b2fa8b2095d7","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2024-04-09T08:40:08Z","title_canon_sha256":"36c589a86f2755680ba939f5222147b024b9255b415c2c4f2da43024f5cd37bd"},"schema_version":"1.0","source":{"id":"2404.06117","kind":"arxiv","version":1}},"canonical_sha256":"466283f236132131208b0942b6707ae5fb3f5c66f9536d4a52038ac1db1988a2","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"466283f236132131208b0942b6707ae5fb3f5c66f9536d4a52038ac1db1988a2","first_computed_at":"2026-07-05T08:06:04.431672Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T08:06:04.431672Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"zsI434/oD/7rDPVZybVFAHMgvZTgEPWVxsr2V1SvYeghoiBfF0mek8mej6vQsaBTwsMvH5a0NYv0SWZL1FSVBA==","signature_status":"signed_v1","signed_at":"2026-07-05T08:06:04.432150Z","signed_message":"canonical_sha256_bytes"},"source_id":"2404.06117","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5f4fea5421665e0a350d4ebcc8ffec5b434e3fe5b65e55d1bc9a5b3a598c88bd","sha256:f93135ff9a26954f43d22017ba67f5dc876307173b9296a0b872a7c1340f3eaa"],"state_sha256":"811965ec30be50ad7cb21d2285e29b8a99d0d5d34191645a72145d3a05a72922"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rMIbOaF3DjvnZWYexqDWtugp3pHwYrNW39hhP8WwnsAIpx6rnt0DOsyuv+G2yrFPfYzAXGZEtcsUWy5EfJQqBA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-04T03:57:03.465838Z","bundle_sha256":"b6a74ddb66d08c56239f9f7afaabad2a546456c91a88a06ec2f019c715bc0a1f"}}