Quantum Contact H3 — Structured Signal Detection in a Double-Slit Optical Channel (Zenodo Working Paper, 2026-03-07)

This working paper synthesizes the H3 line of the Quantum Contact project. H3 asks whether the decoded output of a laser-based double-slit optical system can contain recurrent, structured patterns — preambles, beacons, or organized signals — rather than uncorrelated noise. The paper describes the physical channel (laser, tube, double slit, sensors S1-S3, state marker S4), the decoding pipeline, the search logic, and the competing hypotheses H3 is designed to separate (random coincidence, instrumental artifact, informational contamination, observer self-imprint, trans-temporal self-beacon, non-conventional external influence). Reconstructed findings include repeated preamble detections, old beacon recurrence (8 detections in one report), and structured blocks repeated up to 30 times in a consolidated summary. This edition is an exploratory anomaly report and methodological consolidation, not a closed proof of a non-conventional source. Raw datasets will be deposited in a future Zenodo v2 release.