State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China.
Nano Lett. 2012 May 9;12(5):2494-8. doi: 10.1021/nl300659v. Epub 2012 Apr 6.
By utilizing a dielectric-film-coated asymmetric T-shape single slit, comprising two grooves of slightly detuned widths immediately contacting with a single nanoslit, the plasmon-induced transparency was experimentally demonstrated. Because of the symmetry breaking in the unit-cell structure, the scattered lights from the two grooves with slightly detuned widths interfere destructively, leading to the plasmon-induced transparency. As a result, a response spectrum with nearly the same interference contrast but a much narrower bandwidth emerges in the unit-cell structure with the footprint of only about 0.9 μm(2), compared with that in the symmetric T-shape single slit. These pronounced features in the structure, such as the increased quality factor, ultracompact size, easy fabrication, and experimental observation, have significant applications in ultracompact plasmonic devices.
利用介质膜涂覆的非对称 T 型单缝，包括两个略微失谐宽度的凹槽，立即与单个纳米狭缝接触，实验证明了等离子体诱导透明。由于单元结构中的对称性破缺，来自两个略微失谐宽度的凹槽的散射光相互相消干涉，导致等离子体诱导透明。结果，在单元结构中出现了一个具有几乎相同的干涉对比度但带宽窄得多的响应光谱，该结构的 footprint 只有约 0.9μm²，与对称 T 型单缝相比。该结构具有明显的特点，如品质因数提高、超紧凑尺寸、易于制造和实验观察等，在超紧凑等离子体器件中有重要应用。
