2013 Fiscal Year Final Research Report
Photonic crystal terahertz-wave absorbers
| Project/Area Number |
24656208
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Osaka University |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
NAGATSUMA Tadao 大阪大学, 大学院基礎工学研究科, 教授 (00452417)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | テラヘルツ波 / フォトニック結晶 / 電磁波吸収体 |
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| Research Abstract |
Terahertz (THz) waves, which are located in the region between radio and light waves (0.1 THz - 10 THz), have attracted a great deal of interest in various fields. The highly-efficient THz perfect absorbers have attracted much attention recently due not only to scientific interest but also to various possible applications. However, thin, planar THz-wave absorbers with near perfect absorptivity and sufficiently broad bandwidth have not yet been demonstrated. Here we utilize the in-plane resonance of a thin, planar photonic-crystal slab with negligible absorption loss to successfully demonstrate and visualize THz-wave trapping. We artificially introduce free carriers, which interact with the trapped waves and capture them in the slab by absorption. Our system exhibits an experimental absorptivity (interaction efficiency) of > 99 % and a broad bandwidth (absorptivity >= 90 %) that covers 17 % of the centre frequency.
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