Binary THz modulator based on silicon Schottky-metasurface
Abstract We propose a metasurface THz modulator based on split-ring resonators (SRRs) formed by four interconnected horizontal Si–Au Schottky diodes. The equivalent junction capacitance of each SRR in the proposed modulator is much smaller than that of the previously reported metasurface counterpart...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-11-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-23534-w |
| _version_ | 1828098532619321344 |
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| author | Saeedeh Ahadi Mohammad Neshat Mohammad Kazem Moravvej-Farshi |
| author_facet | Saeedeh Ahadi Mohammad Neshat Mohammad Kazem Moravvej-Farshi |
| author_sort | Saeedeh Ahadi |
| collection | DOAJ |
| description | Abstract We propose a metasurface THz modulator based on split-ring resonators (SRRs) formed by four interconnected horizontal Si–Au Schottky diodes. The equivalent junction capacitance of each SRR in the proposed modulator is much smaller than that of the previously reported metasurface counterparts with vertical Schottky junctions, leading to a higher modulation speed. To modulate a THz incident signal by the proposed metasurface, we vary the bias voltage externally applied to the Schottky junctions. Applying a reverse bias of V A = − 5 V to the Au gate, two LC resonances at 0.48 THz, and 0.95 THz are excited in the metasurface. Switching the applied voltage to V A = + 0.49 V, we diminish the oscillator strengths of the LC resonances, creating one dipole resonance at 0.73 THz in the transmission spectrum of the metasurface modulator. The modulation depths at these resonances are more than 45%, reaching 87% at 0.95 THz. The phase modulation for this THz modulator is about 1.12 rad at 0.86 THz. Furthermore, due to the particular design of the meta-atoms, the modulation speed of this device is estimated up to approximately several hundred GHz, which makes this device an appropriate candidate for high-speed applications in wireless communications systems based on external modulators. |
| first_indexed | 2024-04-11T08:04:07Z |
| format | Article |
| id | doaj.art-cbe3a3be7a414f9b81883b045c752d9e |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-11T08:04:07Z |
| publishDate | 2022-11-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-cbe3a3be7a414f9b81883b045c752d9e2022-12-22T04:35:37ZengNature PortfolioScientific Reports2045-23222022-11-0112111010.1038/s41598-022-23534-wBinary THz modulator based on silicon Schottky-metasurfaceSaeedeh Ahadi0Mohammad Neshat1Mohammad Kazem Moravvej-Farshi2Nano Plasmo-Photonic Research Group, Faculty of Electrical and Computer Engineering, Tarbiat Modares UniversitySchool of Electrical and Computer Engineering, College of Engineering, University of TehranNano Plasmo-Photonic Research Group, Faculty of Electrical and Computer Engineering, Tarbiat Modares UniversityAbstract We propose a metasurface THz modulator based on split-ring resonators (SRRs) formed by four interconnected horizontal Si–Au Schottky diodes. The equivalent junction capacitance of each SRR in the proposed modulator is much smaller than that of the previously reported metasurface counterparts with vertical Schottky junctions, leading to a higher modulation speed. To modulate a THz incident signal by the proposed metasurface, we vary the bias voltage externally applied to the Schottky junctions. Applying a reverse bias of V A = − 5 V to the Au gate, two LC resonances at 0.48 THz, and 0.95 THz are excited in the metasurface. Switching the applied voltage to V A = + 0.49 V, we diminish the oscillator strengths of the LC resonances, creating one dipole resonance at 0.73 THz in the transmission spectrum of the metasurface modulator. The modulation depths at these resonances are more than 45%, reaching 87% at 0.95 THz. The phase modulation for this THz modulator is about 1.12 rad at 0.86 THz. Furthermore, due to the particular design of the meta-atoms, the modulation speed of this device is estimated up to approximately several hundred GHz, which makes this device an appropriate candidate for high-speed applications in wireless communications systems based on external modulators.https://doi.org/10.1038/s41598-022-23534-w |
| spellingShingle | Saeedeh Ahadi Mohammad Neshat Mohammad Kazem Moravvej-Farshi Binary THz modulator based on silicon Schottky-metasurface Scientific Reports |
| title | Binary THz modulator based on silicon Schottky-metasurface |
| title_full | Binary THz modulator based on silicon Schottky-metasurface |
| title_fullStr | Binary THz modulator based on silicon Schottky-metasurface |
| title_full_unstemmed | Binary THz modulator based on silicon Schottky-metasurface |
| title_short | Binary THz modulator based on silicon Schottky-metasurface |
| title_sort | binary thz modulator based on silicon schottky metasurface |
| url | https://doi.org/10.1038/s41598-022-23534-w |
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