Full-Text Access and Download Requests ====================================== **Checked: 19 October 2026.** Full-text downloads were attempted for all 13 papers originally listed in :doc:`literature`. Five readable PDFs were obtained from publisher or author-repository hosts, and seven more were supplied locally. Two additional review papers have since been supplied and added, bringing the bibliography to **15 papers**. All nine supplied PDFs match the cited papers by title, authors, venue, year, and page range, and their text was successfully extracted. Relevant sections of all **14 available papers** were consulted. Only the Hibino et al. (1994) PLC conference paper is still missing. The survey distinguishes results verified from complete manuscripts from details supported only by publisher abstracts. Downloaded papers were used for research; this site links their original hosts rather than redistributing the PDFs. The :download:`BibTeX bibliography ` supplies titles and authors for library searches. PDFs obtained and consulted --------------------------- .. list-table:: Available full texts and sections used :header-rows: 1 :widths: 28 32 40 * - Paper - Download source - Reading performed for this survey * - R1: Fan (2005) - Supplied local publisher PDF; 11 pages - Sections I–III and V on combining classes, field-control requirements, coherent architectures, and spectral/coherent trade-offs. * - R2: Stachowiak (2018) - `Publisher PDF `_ - Sections 1–2 on component construction and section 4.2 on multimode acceptance/brightness ratio. * - R3: Birks et al. (2015) - `arXiv author manuscript `_ - Section 3.1 on thermodynamics, independent modes, coherent exceptions, and mode-number matching. * - R4: Smit and van Dam (1996) - `University-hosted published PDF `_ - Introduction and basic-operation discussion, including dispersion and transmission metrics. * - R5: Singh (1999) - Supplied local publisher PDF; 10 pages including a publisher cover - Silica waveguide platform, directional couplers, 1-by-N splitter construction, and wavelength multiplexers. * - R6: Lei et al. (2020) - Supplied local publisher PDF; 14 pages - Taper geometry, pump-input NA, backward coupling, and fabrication-induced signal-beam degradation in sections 3–4. * - R7: Agarwal (1987) - Supplied local publisher PDF; 28 pages including a publisher cover - Construction taxonomy and configurations on pages 27–44, mode-dependent characterization on pages 45–47, and SM coupler technology on pages 47–49. * - R8: Marchetti et al. (2019) - Supplied local publisher PDF; 39 pages - Interface taxonomy, fiber and edge-coupling principles in sections 1–3, grating principles in section 4.A, packaging in section 6, and conclusions and comparison-table notes in section 7. * - O1: Kawasaki and Hill (1977) - Supplied local publisher PDF; 2 pages - Fabrication, excess-loss definition, experimental launch, mode conversion, and output mode mixing. * - O2: Kawasaki et al. (1981) - Supplied local publisher PDF; 2 pages - Device fabrication, 30-device evaluation, fundamental-mode launch conditions, wavelength dependence, and packaging. * - O4: Smit (1988) - `University-hosted published PDF `_ - Original component principle, experimental realization, and conclusion on pages 385–386. * - O5: Kozlov et al. (1999) - Supplied local publisher PDF; 3 pages - Shared-cavity half-coupler architecture, Bragg-grating tuning, injection locking, analyzer resolution, and cleave-dependent output fields. * - O6: Leon-Saval et al. (2005) - Supplied local publisher PDF; 3 pages - The 19-port grating-filter experiment, measured 3.4% transmission, mode-number mismatch, and proposed fabrication improvements. * - O7: Morizur et al. (2010) - `arXiv author preprint `_ - Theory, experimental implementation, and the distinction between mode overlap and total transmission efficiency. The seven supplied copies resolve the earlier access failures for Fan, Singh, Lei, Kawasaki/Hill, Kawasaki et al., Kozlov, and Leon-Saval. Their full-text results now inform the survey and annotated bibliography. The two later additions are *Review of optical fiber couplers* and *Coupling strategies for silicon photonics integrated chips [Invited]*. They are additional reviews, not substitutes for the missing Hibino paper. Full texts still needed ----------------------- The only remaining request is **O3: Hibino et al. (1994)**. A later review or related paper does not replace inspection of this particular conference publication and its complete reliability data. .. list-table:: Paper whose full text is still needed :header-rows: 1 :widths: 24 40 36 * - Paper and identifier - Title - Access result and evidence actually available * - O3: Hibino et al. (1994), `10.1364/OFC.1994.PD7 `_ - Silica-based PLC splitters which satisfy reliability requirements for more than 5000 hours - Publisher route returned HTML rather than a PDF; abstract and bibliographic record were read. Patent access -------------- The seven :doc:`patent disclosures ` were available as online specifications, with descriptions and figures accessible through their linked records. Their technical descriptions were consulted for this survey. Original PDF links are supplied where resolved; the remaining record includes a PDF download link. No patent-access request remains.