Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing?
The unique ability of slot and sub-wavelength grating (SWG) waveguides to confine light outside of the waveguide core material has attracted significant interest in their application to chemical and biological sensing. However, high sensitivity to sidewall roughness induced scattering loss in thes...
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| Format: | Article |
| Language: | en_US |
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Optical Society of America
2018
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| Online Access: | http://hdl.handle.net/1721.1/117587 https://orcid.org/0000-0003-0740-1344 https://orcid.org/0000-0002-4942-1709 https://orcid.org/0000-0001-7327-4967 https://orcid.org/0000-0002-7233-3918 |
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| author | Kita, Derek M. Michon, Jerome Johnson, Steven G Hu, Juejun |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Kita, Derek M. Michon, Jerome Johnson, Steven G Hu, Juejun |
| author_sort | Kita, Derek M. |
| collection | MIT |
| description | The unique ability of slot and sub-wavelength grating (SWG) waveguides to confine light outside of the waveguide core material has attracted significant interest in their application to chemical and biological sensing. However, high sensitivity to sidewall roughness induced scattering loss in these structures compared to strip waveguides casts doubt on their efficacy. In this article, we seek to settle the controversy for silicon-on- insulator (SOI) photonic devices by quantitatively comparing the sensing performance of various waveguide geometries through figures of merit that we derive for each mode of sensing. These methods (which may be readily applied to other material systems) take into account both modal confinement and roughness scattering loss, the latter of which is computed using a volume-current (Green’s-function) method with a first Born approximation. For devices based on the standard 220 nm SOI platform at telecommu- nication wavelengths ( λ = 1550 nm) whose propagation loss is predominantly limited by random line-edge sidewall roughness scattering, our model predicts that properly engineered TM-polarized strip waveguides claim the best performance for refractome- try and absorption spectroscopy, while optimized slot waveguides demonstrate > 5 × performance enhancement over the other waveguide geometries for waveguide-enhanced Raman spectroscopy. |
| first_indexed | 2024-09-23T11:44:01Z |
| format | Article |
| id | mit-1721.1/117587 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:44:01Z |
| publishDate | 2018 |
| publisher | Optical Society of America |
| record_format | dspace |
| spelling | mit-1721.1/1175872022-10-01T05:38:30Z Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? Kita, Derek M. Michon, Jerome Johnson, Steven G Hu, Juejun Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Materials Systems Laboratory Massachusetts Institute of Technology. Research Laboratory of Electronics Kita, Derek, M. Kita, Derek M. Michon, Jerome Johnson, Steven G Hu, Juejun The unique ability of slot and sub-wavelength grating (SWG) waveguides to confine light outside of the waveguide core material has attracted significant interest in their application to chemical and biological sensing. However, high sensitivity to sidewall roughness induced scattering loss in these structures compared to strip waveguides casts doubt on their efficacy. In this article, we seek to settle the controversy for silicon-on- insulator (SOI) photonic devices by quantitatively comparing the sensing performance of various waveguide geometries through figures of merit that we derive for each mode of sensing. These methods (which may be readily applied to other material systems) take into account both modal confinement and roughness scattering loss, the latter of which is computed using a volume-current (Green’s-function) method with a first Born approximation. For devices based on the standard 220 nm SOI platform at telecommu- nication wavelengths ( λ = 1550 nm) whose propagation loss is predominantly limited by random line-edge sidewall roughness scattering, our model predicts that properly engineered TM-polarized strip waveguides claim the best performance for refractome- try and absorption spectroscopy, while optimized slot waveguides demonstrate > 5 × performance enhancement over the other waveguide geometries for waveguide-enhanced Raman spectroscopy. National Science Foundation (U.S.) (ward No. 1709212) United States. Army Research Office (contract number W911NF-13-D-0001) 2018-08-28T16:07:00Z 2018-08-28T16:07:00Z 2018-08 Article http://purl.org/eprint/type/JournalArticle 2334-2536 http://hdl.handle.net/1721.1/117587 Kita, Derek M., Jérôme Michon, Steven G. Johnson, and Juejun Hu. “Are Slot and Sub-Wavelength Grating Waveguides Better Than Strip Waveguides for Sensing?” Optica 5, no. 9 (August 23, 2018): 1046. https://orcid.org/0000-0003-0740-1344 https://orcid.org/0000-0002-4942-1709 https://orcid.org/0000-0001-7327-4967 https://orcid.org/0000-0002-7233-3918 en_US https://doi.org/10.1364/OPTICA.5.001046 Optica Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Optical Society of America Kita, Derek M. |
| spellingShingle | Kita, Derek M. Michon, Jerome Johnson, Steven G Hu, Juejun Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title | Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title_full | Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title_fullStr | Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title_full_unstemmed | Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title_short | Are slot and sub-wavelength grating waveguides better than strip waveguides for sensing? |
| title_sort | are slot and sub wavelength grating waveguides better than strip waveguides for sensing |
| url | http://hdl.handle.net/1721.1/117587 https://orcid.org/0000-0003-0740-1344 https://orcid.org/0000-0002-4942-1709 https://orcid.org/0000-0001-7327-4967 https://orcid.org/0000-0002-7233-3918 |
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