{
  "abstract": "We demonstrate a multifunctional engineered χ ⁽²⁾ photonic crystal that integrates second-harmonic generation, wavelength selectivity, beam splitting, and focusing within a single χ ⁽²⁾ -modulated ferroelectric photonic structure. Rather than encoding a single nonlinear wavefront, the engineered spatial χ ⁽²⁾ modulation multiplexes wavelength-dependent phase-mismatch compensation and wavefront-encoding conditions, allowing different pump wavelengths to access distinct second-harmonic focusing responses. As a proof of concept, a 1050 nm pump is converted to 525 nm second-harmonic light and focused into two spatially separated spots, whereas a 1100 nm pump is converted to 550 nm second-harmonic light and focused into three spots. The measured multi-spot patterns and deflection angles agree well with the numerical design, while wavelength-resolved measurements confirm selective excitation of the encoded double-focus and triple-focus channels. These results establish a compact strategy for multiplexing independently prescribed nonlinear output functions within a single engineered χ ⁽²⁾ structure.",
  "abstract_shown": true,
  "affiliations": [
    "Australian National University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "name": "Zongheng Cui"
    },
    {
      "name": "Tianxiang Xu",
      "orcid": "0000-0002-5492-0959"
    },
    {
      "affs": [
        0
      ],
      "name": "Shan Liu"
    },
    {
      "name": "Ruwei Zhao"
    },
    {
      "name": "Yan Sheng"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7xdwwv8w0m6ws.bib",
  "cited_by": 0,
  "doi": "10.1364/oe.612943",
  "fulltext_url": null,
  "id": "7xdwwv8w0m6ws",
  "issns": [
    "1094-4087"
  ],
  "landing_url": "https://opg.optica.org/abstract.cfm?URI=oe-34-21-39108",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Photorefractive and Nonlinear Optics"
    ]
  ],
  "openalex": "W7220848259",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": "Optica Publishing Group",
  "ris": "https://research.draconitic.com/paper/7xdwwv8w0m6ws.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:09Z",
      "native_id": "10.1364/oe.612943",
      "source": "crossref",
      "url": "https://opg.optica.org/abstract.cfm?URI=oe-34-21-39108"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Photorefractive and Nonlinear Optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "Wavelength-selective second-harmonic splitting and focusing in engineered χ ⁽²⁾ photonic crystals",
  "title_text": "Wavelength-selective second-harmonic splitting and focusing in engineered χ ⁽²⁾ photonic crystals",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:09Z",
  "url": "https://research.draconitic.com/paper/7xdwwv8w0m6ws",
  "venue": "Optics Express",
  "versions": []
}