Approaching total absorption of graphene strips using a c-Si subwavelength periodic membrane
Approaching total absorption of graphene strips using a c-Si subwavelength periodic membrane
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DOI：
10.1016/j.optcom.2017.12.065
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发表时间：
2018-04
影响因子：
2.4
通讯作者：
Tian Sang;Rui Wang;Junlang Li;Jian-yu Zhou;Yueke Wang
中科院分区：
文献类型：
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作者：
Tian Sang;Rui Wang;Junlang Li;Jian-yu Zhou;Yueke Wang
提出了一种利用晶体硅(c-Si)亚波长周期膜(SPM)实现石墨烯近红外全吸收的方法。在c-Si SPM中，由于导模和辐射模之间的耦合，在近垂直入射时，通过结构的对称性破缺，共振针尖可以增强石墨烯的吸收。在共振时，电场强度提高了1 939倍，群速度降至3.5 5×10−4c，在入射角度为2°时，通过临界耦合可获得99.3%的吸收。通过改变刻蚀厚度、刻蚀宽度和刻蚀周期，可以保持对石墨烯的高吸收。当这种带石墨烯的c-Si SPM用于折射率传感器时，由于其稳定的近均一吸收，它表现出了优异的传感性能。
Approaching total absorption of graphene strips at near infrared using a crystalline-silicon (c-Si) subwavelength periodic membrane (SPM) is presented. The absorption in graphene strips in a c-Si SPM is enhanced by a resonant tip, which is resulted from the coupling between the guided mode and the radiation mode through symmetry breaking of the structure at near-normal incidence. The enhancement of the electric field intensity is increased 1939 times and the group velocity of light is decreased to 3.55× 10− 4 c at resonance, and 99.3% absorption in graphene strips can be achieved by critical coupling at the incident angle of 2°. High absorption of the graphene strips can be maintained as the etching thickness, the strip width, and the period are altered. When this type of c-Si SPM with graphene strips is used in refractive index sensors, it shows excellent sensing properties due to its stable near-unity absorption.