Academic Journal
Anomalous extinction in index-matched terahertz nanogaps
| العنوان: | Anomalous extinction in index-matched terahertz nanogaps |
|---|---|
| المؤلفون: | Jeong Jeeyoon, Kim Dasom, Park Hyeong-Ryeol, Kang Taehee, Lee Dukhyung, Kim Sunghwan, Bahk Young-Mi, Kim Dai-Sik |
| المصدر: | Nanophotonics, Vol 7, Iss 1, Pp 347-354 (2018) |
| بيانات النشر: | De Gruyter, 2018. |
| سنة النشر: | 2018 |
| المجموعة: | LCC:Physics |
| مصطلحات موضوعية: | terahertz nanogaps, reflection, field enhancement, terahertz nonlinearity, index matching, Physics, QC1-999 |
| الوصف: | Slot-type nanogaps have been widely utilized in transmission geometry because of their advantages of exclusive light funneling and exact quantification of near-field enhancement at the gap. For further application of the nanogaps in electromagnetic interactions with various target materials, complementary studies on both transmission and reflection properties of the nanogaps are necessary. Here, we observe an anomalous extinction of terahertz waves interacting with rectangular ring-shaped sub-30 nm wide gaps. Substrate works as an index matching layer for the nanogaps, leading to a stronger field enhancement and increased nonlinearity at the gap under substrate-side illumination. This effect is expressed in reflection as a larger dip at the resonance, caused by destructive interference of the diffracted field from the gap with the reflected beam from the metal. The resulting extinction at the resonance is larger than 60% of the incident power, even without any absorbing material in the whole nanogap structure. The extinction even decreases in the presence of an absorbing medium on top of the nanogaps, suggesting that transmission and reflection from nanogaps might not necessarily represent the absorption of the whole structure. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2192-8606 2192-8614 |
| Relation: | https://doaj.org/toc/2192-8606; https://doaj.org/toc/2192-8614 |
| DOI: | 10.1515/nanoph-2017-0058 |
| URL الوصول: | https://doaj.org/article/ed42e8adf51e47cc8f7faf0c6e3280de |
| رقم الانضمام: | edsdoj.42e8adf51e47cc8f7faf0c6e3280de |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 21928606 21928614 |
|---|---|
| DOI: | 10.1515/nanoph-2017-0058 |