{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T02:35:26Z","timestamp":1769740526244,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,4,13]],"date-time":"2020-04-13T00:00:00Z","timestamp":1586736000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61771138"],"award-info":[{"award-number":["61771138"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61974094"],"award-info":[{"award-number":["61974094"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61831012"],"award-info":[{"award-number":["61831012"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51572042"],"award-info":[{"award-number":["51572042"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100013287","name":"Science Challenge Project","doi-asserted-by":"publisher","award":["TZ2018003"],"award-info":[{"award-number":["TZ2018003"]}],"id":[{"id":"10.13039\/501100013287","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Science &amp; Technology Innovation Institute of Dongguan University of Technology","award":["KCYCXPT2017004"],"award-info":[{"award-number":["KCYCXPT2017004"]}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["2018M643651"],"award-info":[{"award-number":["2018M643651"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Nanostructures can induce light multireflection, enabling strong light absorption and efficient photocarrier generation. In this work, silicon nanostructures, including nanocylinders, nanotips, and nanoholes, were proposed as all-optical broadband THz modulators. The modulation properties of these modulators were simulated and compared with finite element method calculations. It is interesting to note that the light reflectance values from all nanostructure were greatly suppressed, showing values of 26.22%, 21.04%, and 0.63% for nanocylinder, nanohole, and nanotip structures, respectively, at 2 THz. The calculated results show that under 808 nm illumination light, the best modulation performance is achieved in the nanotip modulator, which displays a modulation depth of 91.63% with a pumping power of 60 mW\/mm2 at 2 THz. However, under shorter illumination wavelengths, such as 532 nm, the modulation performance for all modulators deteriorates and the best performance is found with the nanohole-based modulator rather than the nanotip-based one. To further clarify the effects of the nanostructure and wavelength on the THz modulation, a graded index layer model was established and the simulation results were explained. This work may provide a further theoretical guide for the design of optically tunable broadband THz modulators.<\/jats:p>","DOI":"10.3390\/s20082198","type":"journal-article","created":{"date-parts":[[2020,4,13]],"date-time":"2020-04-13T10:41:52Z","timestamp":1586774512000},"page":"2198","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["An Optically Tunable THz Modulator Based on Nanostructures of Silicon Substrates"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4247-1252","authenticated-orcid":false,"given":"Chen","family":"Mo","sequence":"first","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"},{"name":"College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518061, China"}]},{"given":"Jingbo","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"}]},{"given":"Dongshan","family":"Wei","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8852-3951","authenticated-orcid":false,"given":"Honglei","family":"Wu","sequence":"additional","affiliation":[{"name":"College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518061, China"}]},{"given":"Qiye","family":"Wen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China"}]},{"given":"Dongxiong","family":"Ling","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering and Intelligentization, Dongguan University of Technology, Dongguan 523808, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ullah, Z., Witjaksono, G., Nawi, I., Tansu, N., Irfan Khattak, M., and Junaid, M. 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