Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform
Abstract Inverse design via topology optimization has led to innovations in integrated photonics and offers a promising way for designing high-efficiency on-chip couplers with a minimal footprint. In this work, we exploit topology optimization to design a compact vertical coupler incorporating a bot...
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Nature Portfolio
2025-01-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-025-86161-1 |
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| author | Shiang-Yu Huang Stefanie Barz |
| author_facet | Shiang-Yu Huang Stefanie Barz |
| author_sort | Shiang-Yu Huang |
| collection | DOAJ |
| description | Abstract Inverse design via topology optimization has led to innovations in integrated photonics and offers a promising way for designing high-efficiency on-chip couplers with a minimal footprint. In this work, we exploit topology optimization to design a compact vertical coupler incorporating a bottom reflector, which achieves sub-decibel coupling efficiency on the 220-nm silicon-on-insulator platform. The final design of the vertical coupler yields a predicted coupling efficiency of −0.35 dB at the wavelength of 1550 nm with a footprint of 14 µm $$\times$$ × 14 µm, which is considerably smaller than conventional grating couplers. Its topology-optimized geometry can be realized by applying one full-etch and one 70-nm shallow-etch process and the fabricability is also guaranteed by a minimum feature size around 150 nm. Analysis of the potential fabrication imperfections indicates that the topology-optimized coupler is more resilient to in-plane variations, as the deviation of approximately ±100 nm in the misalignment of the topology-optimized features, ±20 nm in the size of the topology-optimized features, and ±10 nm in shallow etch depth yields an additional 1-dB loss as a penalty at the wavelength of 1550 nm. The proposed vertical coupler can further miniaturize photonic integrated circuits and enable highly-efficient networks between optical fibers and other photonic devices. |
| format | Article |
| id | doaj-art-fc8c1e35901a49bf8896d02ebbed9089 |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
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| series | Scientific Reports |
| spelling | doaj-art-fc8c1e35901a49bf8896d02ebbed90892025-01-26T12:26:24ZengNature PortfolioScientific Reports2045-23222025-01-011511910.1038/s41598-025-86161-1Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platformShiang-Yu Huang0Stefanie Barz1Institute for Functional Matter and Quantum Technologies, University of StuttgartInstitute for Functional Matter and Quantum Technologies, University of StuttgartAbstract Inverse design via topology optimization has led to innovations in integrated photonics and offers a promising way for designing high-efficiency on-chip couplers with a minimal footprint. In this work, we exploit topology optimization to design a compact vertical coupler incorporating a bottom reflector, which achieves sub-decibel coupling efficiency on the 220-nm silicon-on-insulator platform. The final design of the vertical coupler yields a predicted coupling efficiency of −0.35 dB at the wavelength of 1550 nm with a footprint of 14 µm $$\times$$ × 14 µm, which is considerably smaller than conventional grating couplers. Its topology-optimized geometry can be realized by applying one full-etch and one 70-nm shallow-etch process and the fabricability is also guaranteed by a minimum feature size around 150 nm. Analysis of the potential fabrication imperfections indicates that the topology-optimized coupler is more resilient to in-plane variations, as the deviation of approximately ±100 nm in the misalignment of the topology-optimized features, ±20 nm in the size of the topology-optimized features, and ±10 nm in shallow etch depth yields an additional 1-dB loss as a penalty at the wavelength of 1550 nm. The proposed vertical coupler can further miniaturize photonic integrated circuits and enable highly-efficient networks between optical fibers and other photonic devices.https://doi.org/10.1038/s41598-025-86161-1 |
| spellingShingle | Shiang-Yu Huang Stefanie Barz Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform Scientific Reports |
| title | Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform |
| title_full | Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform |
| title_fullStr | Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform |
| title_full_unstemmed | Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform |
| title_short | Compact inverse designed vertical coupler with bottom reflector for sub-decibel fiber-to-chip coupling on silicon on insulator platform |
| title_sort | compact inverse designed vertical coupler with bottom reflector for sub decibel fiber to chip coupling on silicon on insulator platform |
| url | https://doi.org/10.1038/s41598-025-86161-1 |
| work_keys_str_mv | AT shiangyuhuang compactinversedesignedverticalcouplerwithbottomreflectorforsubdecibelfibertochipcouplingonsilicononinsulatorplatform AT stefaniebarz compactinversedesignedverticalcouplerwithbottomreflectorforsubdecibelfibertochipcouplingonsilicononinsulatorplatform |