{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:BJIMHGCOFRDANX2SFMM4SRW5PO","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":"3aa8ecfb9c4cac7d94a782a13f6501a64526a71bbe783c06808e116891e887ce","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2013-05-30T04:30:30Z","title_canon_sha256":"894fad1752cfc41262b49c9e6469dfd4141e586b0830443b253815e2fc095680"},"schema_version":"1.0","source":{"id":"1305.7000","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1305.7000","created_at":"2026-05-18T03:22:16Z"},{"alias_kind":"arxiv_version","alias_value":"1305.7000v1","created_at":"2026-05-18T03:22:16Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1305.7000","created_at":"2026-05-18T03:22:16Z"},{"alias_kind":"pith_short_12","alias_value":"BJIMHGCOFRDA","created_at":"2026-05-18T12:27:38Z"},{"alias_kind":"pith_short_16","alias_value":"BJIMHGCOFRDANX2S","created_at":"2026-05-18T12:27:38Z"},{"alias_kind":"pith_short_8","alias_value":"BJIMHGCO","created_at":"2026-05-18T12:27:38Z"}],"graph_snapshots":[{"event_id":"sha256:601fb7fedd4357dd2d446e00eb177b56b6b0034ab99305f87e132b40ace0f4ed","target":"graph","created_at":"2026-05-18T03:22:16Z","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"},"paper":{"abstract_excerpt":"We demonstrate optical time domain reflectometry over 200 km of optical fiber using low-noise NbTiN superconducting single-photon detectors integrated with Si3N4 waveguides. Our small detector footprint enables high timing resolution of 50ps and a dark count rate of 3 Hz with unshielded fibers, allowing for identification of defects along the fiber over a dynamic range of 37.4 dB. Photons scattered and reflected back from the fiber under test can be detected in free-running mode without showing dead zones or other impairments often encountered in semiconductor photon-counting optical time doma","authors_text":"Carsten Schuck, Hong X. Tang, Wolfram H. P. Pernice, Xiaosong Ma","cross_cats":["quant-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2013-05-30T04:30:30Z","title":"Optical time domain reflectometry with low noise waveguide-coupled superconducting nanowire single-photon detectors"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1305.7000","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:f82c3369d0bd981e4b6f86511e6c401b8ce5f42890e29d6d937065a3f66a150a","target":"record","created_at":"2026-05-18T03:22:16Z","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":"3aa8ecfb9c4cac7d94a782a13f6501a64526a71bbe783c06808e116891e887ce","cross_cats_sorted":["quant-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2013-05-30T04:30:30Z","title_canon_sha256":"894fad1752cfc41262b49c9e6469dfd4141e586b0830443b253815e2fc095680"},"schema_version":"1.0","source":{"id":"1305.7000","kind":"arxiv","version":1}},"canonical_sha256":"0a50c3984e2c4606df522b19c946dd7bb80c2da274f4c030b45ac8db8c2581c9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0a50c3984e2c4606df522b19c946dd7bb80c2da274f4c030b45ac8db8c2581c9","first_computed_at":"2026-05-18T03:22:16.662341Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:22:16.662341Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"DEQP18yj+FQB2NhU/x5HNv0o65WfjN8cD+ZKCKZCbz5xsK6uvP2gBWHRe0/IErrFt8zIwW5J7aI1zvC4siYlAg==","signature_status":"signed_v1","signed_at":"2026-05-18T03:22:16.662972Z","signed_message":"canonical_sha256_bytes"},"source_id":"1305.7000","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f82c3369d0bd981e4b6f86511e6c401b8ce5f42890e29d6d937065a3f66a150a","sha256:601fb7fedd4357dd2d446e00eb177b56b6b0034ab99305f87e132b40ace0f4ed"],"state_sha256":"2231fd4708c84fdb2ad591c6ae7f2cf07adb5137912f888c2b71bb90436f934d"}