{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:VUAG6T7KZ7HYVUDHGZXBCVGQJS","short_pith_number":"pith:VUAG6T7K","canonical_record":{"source":{"id":"2504.20512","kind":"arxiv","version":3},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2025-04-29T07:52:16Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"832fe1342a5c1ded3da50d3a186c77c61fd48dd2f948fceb741c89d8a37ada78","abstract_canon_sha256":"f0461964ac1bf82b139a49c460ebdd5dda81ec25b9137bcbc6d08bfe3d017a9b"},"schema_version":"1.0"},"canonical_sha256":"ad006f4feacfcf8ad067366e1154d04ca533a2cff5d52300862474712e1868b8","source":{"kind":"arxiv","id":"2504.20512","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.20512","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"arxiv_version","alias_value":"2504.20512v3","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.20512","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_12","alias_value":"VUAG6T7KZ7HY","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_16","alias_value":"VUAG6T7KZ7HYVUDH","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_8","alias_value":"VUAG6T7K","created_at":"2026-07-05T10:58:26Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:VUAG6T7KZ7HYVUDHGZXBCVGQJS","target":"record","payload":{"canonical_record":{"source":{"id":"2504.20512","kind":"arxiv","version":3},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2025-04-29T07:52:16Z","cross_cats_sorted":["physics.app-ph"],"title_canon_sha256":"832fe1342a5c1ded3da50d3a186c77c61fd48dd2f948fceb741c89d8a37ada78","abstract_canon_sha256":"f0461964ac1bf82b139a49c460ebdd5dda81ec25b9137bcbc6d08bfe3d017a9b"},"schema_version":"1.0"},"canonical_sha256":"ad006f4feacfcf8ad067366e1154d04ca533a2cff5d52300862474712e1868b8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T10:58:26.863421Z","signature_b64":"aMDy5duHprsQkjfMlvz+95qAVy/EISLeg4RHwmBjNJ+aA50LHL8aSX9OFUJS3od//WibliQ7RpBsuMzuD/5mCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ad006f4feacfcf8ad067366e1154d04ca533a2cff5d52300862474712e1868b8","last_reissued_at":"2026-07-05T10:58:26.862903Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T10:58:26.862903Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2504.20512","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T10:58:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UhSkAI/0c/Hz2VqzvR7K/5pOMadc1GZrQZt9CUvtCbm1ZWfSbyEVMfTyMpAxbxzrTjzs0hrLJcvrkFGr530iBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T16:22:47.227503Z"},"content_sha256":"af4d03a74254417178aa8bc1faf1ba97061fcfc20c860dd3140d1e6ff9ad51e6","schema_version":"1.0","event_id":"sha256:af4d03a74254417178aa8bc1faf1ba97061fcfc20c860dd3140d1e6ff9ad51e6"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:VUAG6T7KZ7HYVUDHGZXBCVGQJS","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Broadband and Ultra-Compact Adiabatic Coupler Based on Linearly Tapered Silicon Waveguides","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":["physics.app-ph"],"primary_cat":"physics.optics","authors_text":"Ahmed Bayoumi, Ahmed Khalil, Dimitrios Velenis, Filippo Ferraro, Joris Van Campenhout, Maumita Chakrabarti, Philippe Absil, Pol Van Dorpe, Qingzhong Deng, Wim Bogaerts, Yoojin Ban","submitted_at":"2025-04-29T07:52:16Z","abstract_excerpt":"2x2 couplers are crucial in many photonics applications but are often wavelength-sensitive. Alternative designs could be large, complex, or lossy. We present a broadband ultra-compact adiabatic coupler with minimal coupling variation and the least silicon taper length of 1.44 um, to our best knowledge."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.20512","kind":"arxiv","version":3},"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/2504.20512/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":"2026-07-05T10:58:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hhyiGYFIP0hMYRzOjFzwkSYfSllbU3ieUOfeerI9aEAgilmrkpKcH5AKe5ZcQZ8QhX/FjW/kVsc1Dl2mkzslAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-06T16:22:47.227874Z"},"content_sha256":"834ccf632620d22c56abc81fb6337083746809e6868f6f61e5e6d1019c2c4cc1","schema_version":"1.0","event_id":"sha256:834ccf632620d22c56abc81fb6337083746809e6868f6f61e5e6d1019c2c4cc1"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/bundle.json","state_url":"https://pith.science/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/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":"2026-07-06T16:22:47Z","links":{"resolver":"https://pith.science/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS","bundle":"https://pith.science/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/bundle.json","state":"https://pith.science/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VUAG6T7KZ7HYVUDHGZXBCVGQJS/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:VUAG6T7KZ7HYVUDHGZXBCVGQJS","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":"f0461964ac1bf82b139a49c460ebdd5dda81ec25b9137bcbc6d08bfe3d017a9b","cross_cats_sorted":["physics.app-ph"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2025-04-29T07:52:16Z","title_canon_sha256":"832fe1342a5c1ded3da50d3a186c77c61fd48dd2f948fceb741c89d8a37ada78"},"schema_version":"1.0","source":{"id":"2504.20512","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2504.20512","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"arxiv_version","alias_value":"2504.20512v3","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2504.20512","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_12","alias_value":"VUAG6T7KZ7HY","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_16","alias_value":"VUAG6T7KZ7HYVUDH","created_at":"2026-07-05T10:58:26Z"},{"alias_kind":"pith_short_8","alias_value":"VUAG6T7K","created_at":"2026-07-05T10:58:26Z"}],"graph_snapshots":[{"event_id":"sha256:834ccf632620d22c56abc81fb6337083746809e6868f6f61e5e6d1019c2c4cc1","target":"graph","created_at":"2026-07-05T10:58:26Z","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/2504.20512/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"2x2 couplers are crucial in many photonics applications but are often wavelength-sensitive. Alternative designs could be large, complex, or lossy. We present a broadband ultra-compact adiabatic coupler with minimal coupling variation and the least silicon taper length of 1.44 um, to our best knowledge.","authors_text":"Ahmed Bayoumi, Ahmed Khalil, Dimitrios Velenis, Filippo Ferraro, Joris Van Campenhout, Maumita Chakrabarti, Philippe Absil, Pol Van Dorpe, Qingzhong Deng, Wim Bogaerts, Yoojin Ban","cross_cats":["physics.app-ph"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2025-04-29T07:52:16Z","title":"Broadband and Ultra-Compact Adiabatic Coupler Based on Linearly Tapered Silicon Waveguides"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2504.20512","kind":"arxiv","version":3},"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:af4d03a74254417178aa8bc1faf1ba97061fcfc20c860dd3140d1e6ff9ad51e6","target":"record","created_at":"2026-07-05T10:58:26Z","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":"f0461964ac1bf82b139a49c460ebdd5dda81ec25b9137bcbc6d08bfe3d017a9b","cross_cats_sorted":["physics.app-ph"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"physics.optics","submitted_at":"2025-04-29T07:52:16Z","title_canon_sha256":"832fe1342a5c1ded3da50d3a186c77c61fd48dd2f948fceb741c89d8a37ada78"},"schema_version":"1.0","source":{"id":"2504.20512","kind":"arxiv","version":3}},"canonical_sha256":"ad006f4feacfcf8ad067366e1154d04ca533a2cff5d52300862474712e1868b8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ad006f4feacfcf8ad067366e1154d04ca533a2cff5d52300862474712e1868b8","first_computed_at":"2026-07-05T10:58:26.862903Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T10:58:26.862903Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"aMDy5duHprsQkjfMlvz+95qAVy/EISLeg4RHwmBjNJ+aA50LHL8aSX9OFUJS3od//WibliQ7RpBsuMzuD/5mCA==","signature_status":"signed_v1","signed_at":"2026-07-05T10:58:26.863421Z","signed_message":"canonical_sha256_bytes"},"source_id":"2504.20512","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:af4d03a74254417178aa8bc1faf1ba97061fcfc20c860dd3140d1e6ff9ad51e6","sha256:834ccf632620d22c56abc81fb6337083746809e6868f6f61e5e6d1019c2c4cc1"],"state_sha256":"809f837a7a64a35bd74c5d9e75233b72861f25f924785b6a3ad34abbc2e15c29"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"S9k6pQ7iECqC5dYQqleYo6wVD6at6benDyfEVVmlNS5sT1l1p9esqOf5SfOE28T0gszxqet+eFJnlvpE5Zl8CQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-06T16:22:47.229860Z","bundle_sha256":"905c4c093c11531657695e985e7a8fcb17ec99a41aa2bcaf4a305f01bf0da597"}}