{"paper":{"title":"Amplitude Noise Suppression in Frequency-Doubled Lasers: A Lyapunov Mechanism for Intensity Stabilization in Coupled Oscillator Systems","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"Chi-squared coupled-wave dynamics in frequency-doubled lasers admit a Lyapunov functional that suppresses amplitude noise by driving modes to constant intensity.","cross_cats":[],"primary_cat":"physics.optics","authors_text":"Thomas M. Baer","submitted_at":"2026-05-13T16:22:53Z","abstract_excerpt":"Multimode intracavity frequency-doubled lasers can reach states of amplitude noise suppression orders of magnitude beyond the predictions of independent-mode partition statistics. We show that the chi2 coupled-wave dynamics in the doubling crystal admit a Lyapunov functional whose monotone decrease under each crystal pass establishes a constant-intensity manifold as the per-pass descent target of the mode dynamics. We confirm the mechanism in an intracavity frequency-doubled Nd:YVO4-LBO laser, observing a 100 fold contrast between full and Fabry-Perot-filtered output noise at fixed detector ba"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We show that the chi2 coupled-wave dynamics in the doubling crystal admit a Lyapunov functional whose monotone decrease under each crystal pass establishes a constant-intensity manifold as the per-pass descent target of the mode dynamics.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the chi2 coupled-wave equations dominate the intracavity dynamics and that no other loss channels or cavity effects prevent the Lyapunov functional from monotonically decreasing to the constant-intensity manifold.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Chi2 coupling in intracavity frequency doubling admits a Lyapunov functional that monotonically decreases to a constant-intensity manifold, yielding 100-fold noise suppression beyond partition statistics in an Nd:YVO4-LBO laser.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Chi-squared coupled-wave dynamics in frequency-doubled lasers admit a Lyapunov functional that suppresses amplitude noise by driving modes to constant intensity.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"61b01b3694e4d5d004453d788e47d6481a14ad6721ad4df4105dc0544f368437"},"source":{"id":"2605.13745","kind":"arxiv","version":1},"verdict":{"id":"23166ac4-66da-4652-8e3b-1e3cfd3f6c6c","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T17:35:27.974561Z","strongest_claim":"We show that the chi2 coupled-wave dynamics in the doubling crystal admit a Lyapunov functional whose monotone decrease under each crystal pass establishes a constant-intensity manifold as the per-pass descent target of the mode dynamics.","one_line_summary":"Chi2 coupling in intracavity frequency doubling admits a Lyapunov functional that monotonically decreases to a constant-intensity manifold, yielding 100-fold noise suppression beyond partition statistics in an Nd:YVO4-LBO laser.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the chi2 coupled-wave equations dominate the intracavity dynamics and that no other loss channels or cavity effects prevent the Lyapunov functional from monotonically decreasing to the constant-intensity manifold.","pith_extraction_headline":"Chi-squared coupled-wave dynamics in frequency-doubled lasers admit a Lyapunov functional that suppresses amplitude noise by driving modes to constant intensity."},"references":{"count":31,"sample":[{"doi":"","year":1986,"title":"T. Baer, Large-amplitude fluctuations due to longitudi- nal mode coupling in diode-pumped intracavity-doubled Nd:YAG lasers, J. Opt. Soc. Am. B3, 1175 (1986)","work_id":"20a265ae-520f-496e-9125-dac015a38df8","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1964,"title":"S. E. Harris and R. Targ, FM oscillation of the He-Ne laser, Appl. Phys. Lett.5, 202 (1964)","work_id":"16c359dc-3cd7-4db8-93eb-ef4334f95ba7","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1987,"title":"C. R. Wu and L. Mandel, Deterministic chaos in a laser with a saturable absorber, J. Opt. Soc. Am. B4, 1870 (1987)","work_id":"939d7f33-6a1c-4c23-bbc7-f95702a4c68d","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1990,"title":"K. Wiesenfeld, C. Bracikowski, G. James, and R. Roy, Observation of antiphase states in a multimode laser, Phys. Rev. Lett.65, 1749 (1990)","work_id":"0dd5b0b6-1f47-40c8-88a1-3aa0c3154917","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":1993,"title":"Chaos in a multimode solid-state laser system,","work_id":"1b164447-030b-411e-8031-0bfc864c35fe","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":31,"snapshot_sha256":"62edd329a239c63fec63dad1f55a67e70ab982fb3dc3bd53be454f0ae65f55cf","internal_anchors":0},"formal_canon":{"evidence_count":2,"snapshot_sha256":"6147211ac8c818c7c81c75f869d6f6d9c810e451bd421486a36580b517217ffa"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}