{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:JZUJJR3EYDCRRLEGKFXHJOXJNJ","short_pith_number":"pith:JZUJJR3E","canonical_record":{"source":{"id":"1902.05674","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2019-02-15T03:46:37Z","cross_cats_sorted":[],"title_canon_sha256":"10072f78ae68554f4e352607c7821356559b3f1522c829fb2d18da3c32f51810","abstract_canon_sha256":"99f10be470ca2cd9f75a046fdd1b8235896e85606b21557aea7d15af68e38436"},"schema_version":"1.0"},"canonical_sha256":"4e6894c764c0c518ac86516e74bae96a4277f15eb3166869e0e2250df9b4bff7","source":{"kind":"arxiv","id":"1902.05674","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1902.05674","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"arxiv_version","alias_value":"1902.05674v1","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1902.05674","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"pith_short_12","alias_value":"JZUJJR3EYDCR","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_16","alias_value":"JZUJJR3EYDCRRLEG","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_8","alias_value":"JZUJJR3E","created_at":"2026-05-18T12:33:21Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:JZUJJR3EYDCRRLEGKFXHJOXJNJ","target":"record","payload":{"canonical_record":{"source":{"id":"1902.05674","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2019-02-15T03:46:37Z","cross_cats_sorted":[],"title_canon_sha256":"10072f78ae68554f4e352607c7821356559b3f1522c829fb2d18da3c32f51810","abstract_canon_sha256":"99f10be470ca2cd9f75a046fdd1b8235896e85606b21557aea7d15af68e38436"},"schema_version":"1.0"},"canonical_sha256":"4e6894c764c0c518ac86516e74bae96a4277f15eb3166869e0e2250df9b4bff7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:53:56.547943Z","signature_b64":"Ey5SkNwKq9cUk69Jsqo8E2Zdl9GEugvYAWdtvPPf2L42q3aTlO1NFUqxSFTQq8ImuwoXWWtZW5nD2pKItGYIBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"4e6894c764c0c518ac86516e74bae96a4277f15eb3166869e0e2250df9b4bff7","last_reissued_at":"2026-05-17T23:53:56.547346Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:53:56.547346Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1902.05674","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":"2026-05-17T23:53:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"L2HMA4BW2KJSWbXIdEzdmFujJXB3qbx4+XeN0Y/oDWSsailhBJn7dDP0SScNz1B28NsRQiKZGfDCQBhfcpyRBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T21:01:03.064327Z"},"content_sha256":"184b9dcb525269000b8131bb6ae0077571c15ea12bc3e445ff78d7f0859b71b5","schema_version":"1.0","event_id":"sha256:184b9dcb525269000b8131bb6ae0077571c15ea12bc3e445ff78d7f0859b71b5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:JZUJJR3EYDCRRLEGKFXHJOXJNJ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Near-perfect absorber as a subwavelength thickness spatial frequency filter for optical image processing","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.optics","authors_text":"Ann Roberts, Daniel E. Gomez, Enrico Della Gaspera, Evgeniy Panchenko, Kalpana Singh, Lukas Wesemann, Timothy J. Davis","submitted_at":"2019-02-15T03:46:37Z","abstract_excerpt":"Spatial frequency filtering is a fundamental enabler of information processing methods in biological and technical imaging. Most filtering methods, however, require either bulky and expensive optical equipment or some degree of computational processing. Here we experimentally demonstrate on-chip, all-optical spatial frequency filtering using a thin-film perfect absorber structure. We give examples of edge enhancement in an amplitude image as well as conversion of a phase gradient in a wave field into an intensity modulation."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1902.05674","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":""},"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":"2026-05-17T23:53:56Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"deascryygb4cGuY6Kh4oDFh2uV4ZeINcaI/vI190Bk9bvNp8VB+Nb3oWJGdUw1dgtuMwocRDBxFp2peGwmcmDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-02T21:01:03.064681Z"},"content_sha256":"1ba74e04a1c282aab6f59e2818df2d0655b11d913fc43e45b651188efd7f225e","schema_version":"1.0","event_id":"sha256:1ba74e04a1c282aab6f59e2818df2d0655b11d913fc43e45b651188efd7f225e"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/bundle.json","state_url":"https://pith.science/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/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":"2026-06-02T21:01:03Z","links":{"resolver":"https://pith.science/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ","bundle":"https://pith.science/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/bundle.json","state":"https://pith.science/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/JZUJJR3EYDCRRLEGKFXHJOXJNJ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:JZUJJR3EYDCRRLEGKFXHJOXJNJ","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":"99f10be470ca2cd9f75a046fdd1b8235896e85606b21557aea7d15af68e38436","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2019-02-15T03:46:37Z","title_canon_sha256":"10072f78ae68554f4e352607c7821356559b3f1522c829fb2d18da3c32f51810"},"schema_version":"1.0","source":{"id":"1902.05674","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1902.05674","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"arxiv_version","alias_value":"1902.05674v1","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1902.05674","created_at":"2026-05-17T23:53:56Z"},{"alias_kind":"pith_short_12","alias_value":"JZUJJR3EYDCR","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_16","alias_value":"JZUJJR3EYDCRRLEG","created_at":"2026-05-18T12:33:21Z"},{"alias_kind":"pith_short_8","alias_value":"JZUJJR3E","created_at":"2026-05-18T12:33:21Z"}],"graph_snapshots":[{"event_id":"sha256:1ba74e04a1c282aab6f59e2818df2d0655b11d913fc43e45b651188efd7f225e","target":"graph","created_at":"2026-05-17T23:53:56Z","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":"Spatial frequency filtering is a fundamental enabler of information processing methods in biological and technical imaging. Most filtering methods, however, require either bulky and expensive optical equipment or some degree of computational processing. Here we experimentally demonstrate on-chip, all-optical spatial frequency filtering using a thin-film perfect absorber structure. We give examples of edge enhancement in an amplitude image as well as conversion of a phase gradient in a wave field into an intensity modulation.","authors_text":"Ann Roberts, Daniel E. Gomez, Enrico Della Gaspera, Evgeniy Panchenko, Kalpana Singh, Lukas Wesemann, Timothy J. Davis","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2019-02-15T03:46:37Z","title":"Near-perfect absorber as a subwavelength thickness spatial frequency filter for optical image processing"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1902.05674","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":"sha256:184b9dcb525269000b8131bb6ae0077571c15ea12bc3e445ff78d7f0859b71b5","target":"record","created_at":"2026-05-17T23:53:56Z","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":"99f10be470ca2cd9f75a046fdd1b8235896e85606b21557aea7d15af68e38436","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.optics","submitted_at":"2019-02-15T03:46:37Z","title_canon_sha256":"10072f78ae68554f4e352607c7821356559b3f1522c829fb2d18da3c32f51810"},"schema_version":"1.0","source":{"id":"1902.05674","kind":"arxiv","version":1}},"canonical_sha256":"4e6894c764c0c518ac86516e74bae96a4277f15eb3166869e0e2250df9b4bff7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4e6894c764c0c518ac86516e74bae96a4277f15eb3166869e0e2250df9b4bff7","first_computed_at":"2026-05-17T23:53:56.547346Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:53:56.547346Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Ey5SkNwKq9cUk69Jsqo8E2Zdl9GEugvYAWdtvPPf2L42q3aTlO1NFUqxSFTQq8ImuwoXWWtZW5nD2pKItGYIBw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:53:56.547943Z","signed_message":"canonical_sha256_bytes"},"source_id":"1902.05674","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:184b9dcb525269000b8131bb6ae0077571c15ea12bc3e445ff78d7f0859b71b5","sha256:1ba74e04a1c282aab6f59e2818df2d0655b11d913fc43e45b651188efd7f225e"],"state_sha256":"2e6d812ca896e3b29014362b3769026818d0d51f2927a38f0390260edf6ae2b7"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2MuNtHl+kpYjywXOsKZ8fHEsHNaCQ96SnPdXe3NtOv9VdGMTSN6gcxyvUypCfdwvKGZIRg89D+pYjvmHTtjjAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-02T21:01:03.066603Z","bundle_sha256":"127f0e89f2045cd1ba240d2e5f382b1f2eb67295db411a0a263f7a99250a7a53"}}