{"paper":{"title":"Abruptly Focusing and Defocusing Needles of Light and Closed-Form Electromagnetic Wavepackets","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.optics","authors_text":"Ido Kaminer, Liang Jie Wong","submitted_at":"2019-03-03T04:19:15Z","abstract_excerpt":"Fourier optics enforces a tradeoff between length and narrowness in electromagnetic wavepackets, so that a narrow spatial focus diffracts at a large divergence angle, and only infinitely wide beams can remain non-diffracting. We show that it is possible to bypass this tradeoff between the length and narrowness of intensity hotspots, and find a family of electromagnetic wavepackets that abruptly focus to and defocus from high-intensity regions of any aspect ratio. Such features are potentially useful in scenarios where one would like to avoid damaging the surrounding environment, for instance, "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1903.00826","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"}