Trapped modes with extremely high quality factor in a circular array of dielectric nanorods
Trapped modes with extremely high quality factor in a circular array of dielectric nanorods
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DOI：
10.1364/ol.43.005403
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发表时间：
2018-11-01
期刊：
影响因子：
3.6
通讯作者：
Liu, Xiaoping
中科院分区：
文献类型：
--
作者：
Han, Hai-Long;Li, He;Liu, Xiaoping
在这篇论文中，我们研究了由介电纳米棒组成的环链中具有接近零群速度的捕获模式的形成。成功地识别了两种束缚模式：在带边缘形成的规则的下连续共振（BCR）模式和重要的连续区内准束缚态（BIC）捕获模式（类似于等效无限线性链中的BIC）。最低阶捕获模式具有最高的Q因子，其与纳米棒N的数量呈指数增长，BCR的Q近似于exp(0.325N)，准bic的Q近似于exp（0.662N）。有趣的是，即使在非常小的N= 8的情况下，准bic模式也可以获得类似于10(5)的调制解调器高Q因子。这表明我们基于纳米棒的环形谐振器在相同的n下比线性链具有明显的优势。我们的研究结果极大地扩展了基于bic现象的应用范围。(C) 2018年美国光学学会
In this Letter, we investigate the formation of trapped modes with near-zero group velocities in a ring chain composed of dielectric nanorods. Two kinds of bound modes are successfully identified: the regular below-continuum-resonance (BCR) modes formed at the band edge and importantly the quasi-bound-states-in-the-continuum (BIC) trapped modes (similar to the BIC in the equivalent infinite linear chain). The lowest-order trapped mode possesses the highest Q factor, which scales exponentially with the number of nanorods N as Q similar to exp(0.325N) for the BCR and Q similar to exp(0.662N) for the quasi-BIC. Interestingly, a moder ate high Q factor similar to 10(5) can be obtained for the quasi-BIC mode even with a very small N= 8. This suggests that our nanorod-based ring resonator possesses a dear advantage over the linear chain for the same N. Our findings greatly expand the application scope of BIC-based phenomena. (C) 2018 Optical Society of America