Highly efficient dual-level grating couplers for silicon nitride photonics
Abstract We propose and numerically demonstrate a versatile strategy that allows designing highly efficient dual-level grating couplers in different silicon nitride-based photonic platforms. The proposed technique, which can generally be applied to an arbitrary silicon nitride film thickness, is bas...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-09-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-19352-9 |
| _version_ | 1798036312617385984 |
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| author | Valerio Vitali Cosimo Lacava Thalía Domínguez Bucio Frederic Y. Gardes Periklis Petropoulos |
| author_facet | Valerio Vitali Cosimo Lacava Thalía Domínguez Bucio Frederic Y. Gardes Periklis Petropoulos |
| author_sort | Valerio Vitali |
| collection | DOAJ |
| description | Abstract We propose and numerically demonstrate a versatile strategy that allows designing highly efficient dual-level grating couplers in different silicon nitride-based photonic platforms. The proposed technique, which can generally be applied to an arbitrary silicon nitride film thickness, is based on the simultaneous optimization of two grating coupler levels to obtain high directionality and grating-fibre mode matching at the same time. This is achieved thanks to the use of two different linear apodizations, with opposite signs, applied to the two grating levels, whose design parameters are determined by using a particle swarm optimization method. Numerical simulations were carried out considering different silicon nitride platforms with 150, 300, 400 and 500 nm thicknesses and initially employing silicon as the material for the top level grating coupler. The use of Si-rich silicon nitride with a refractive index in the range 2.7–3.3 for the top layer material enabled to obtain similar performance (coupling efficiency exceeding − 0.45 dB for the 400 nm thick silicon nitride platform) with relaxed fabrication tolerances. To the best of our knowledge, these numerical results represent the best performance ever reported in the literature for silicon nitride grating couplers without the use of any back-reflector. |
| first_indexed | 2024-04-11T21:09:42Z |
| format | Article |
| id | doaj.art-5ea5ba14f2ae450687b81ecbe9ce053f |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-11T21:09:42Z |
| publishDate | 2022-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-5ea5ba14f2ae450687b81ecbe9ce053f2022-12-22T04:03:03ZengNature PortfolioScientific Reports2045-23222022-09-0112111210.1038/s41598-022-19352-9Highly efficient dual-level grating couplers for silicon nitride photonicsValerio Vitali0Cosimo Lacava1Thalía Domínguez Bucio2Frederic Y. Gardes3Periklis Petropoulos4Optoelectronics Research Centre, Highfield Campus, University of SouthamptonElectrical, Computer and Biomedical Engineering Department, University of PaviaOptoelectronics Research Centre, Highfield Campus, University of SouthamptonOptoelectronics Research Centre, Highfield Campus, University of SouthamptonOptoelectronics Research Centre, Highfield Campus, University of SouthamptonAbstract We propose and numerically demonstrate a versatile strategy that allows designing highly efficient dual-level grating couplers in different silicon nitride-based photonic platforms. The proposed technique, which can generally be applied to an arbitrary silicon nitride film thickness, is based on the simultaneous optimization of two grating coupler levels to obtain high directionality and grating-fibre mode matching at the same time. This is achieved thanks to the use of two different linear apodizations, with opposite signs, applied to the two grating levels, whose design parameters are determined by using a particle swarm optimization method. Numerical simulations were carried out considering different silicon nitride platforms with 150, 300, 400 and 500 nm thicknesses and initially employing silicon as the material for the top level grating coupler. The use of Si-rich silicon nitride with a refractive index in the range 2.7–3.3 for the top layer material enabled to obtain similar performance (coupling efficiency exceeding − 0.45 dB for the 400 nm thick silicon nitride platform) with relaxed fabrication tolerances. To the best of our knowledge, these numerical results represent the best performance ever reported in the literature for silicon nitride grating couplers without the use of any back-reflector.https://doi.org/10.1038/s41598-022-19352-9 |
| spellingShingle | Valerio Vitali Cosimo Lacava Thalía Domínguez Bucio Frederic Y. Gardes Periklis Petropoulos Highly efficient dual-level grating couplers for silicon nitride photonics Scientific Reports |
| title | Highly efficient dual-level grating couplers for silicon nitride photonics |
| title_full | Highly efficient dual-level grating couplers for silicon nitride photonics |
| title_fullStr | Highly efficient dual-level grating couplers for silicon nitride photonics |
| title_full_unstemmed | Highly efficient dual-level grating couplers for silicon nitride photonics |
| title_short | Highly efficient dual-level grating couplers for silicon nitride photonics |
| title_sort | highly efficient dual level grating couplers for silicon nitride photonics |
| url | https://doi.org/10.1038/s41598-022-19352-9 |
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