Zhang Mingda, Zhang Xiangdong
Department of Physics, Beijing Normal University, Beijing 100875, China.
School of Physics and Beijing Key Laboratory of Nanophotonics &Ultrafine Optoelectronic Systems, Beijing Institute of Technology, 100081, Beijing, China.
Sci Rep. 2015 Feb 5;5:8266. doi: 10.1038/srep08266.
We have designed a sphere-graphene-slab structure so that the electromagnetic wave can be well confined in the graphene due to the formation of a bound state in a continuum (BIC) of radiation modes. Based on such a bound state, we have realized strong optical absorption in the monolayer graphene. Such a strong optical absorption exhibits many advantages. It is ultrasensitive to the wavelength because the Q factor of the absorption peak can be more than 2000. By taking suitable BICs, the selective absorption for S and P waves has not only been realized, but also all-angle absorption for the S and P waves at the same time has been demonstrated. We have also found that ultrasensitive strong absorptions can appear at any wavelength from mid-infrared to far-infrared band. These phenomena are very beneficial to biosensing, perfect filters and waveguides.
我们设计了一种球体 - 石墨烯 - 平板结构，这样由于辐射模式的连续统中的束缚态（BIC）的形成，电磁波可以很好地限制在石墨烯中。基于这种束缚态，我们在单层石墨烯中实现了强光吸收。这种强光吸收具有许多优点。它对波长极其敏感，因为吸收峰的品质因数可以超过2000。通过采用合适的BIC，不仅实现了对S波和P波的选择性吸收，还同时证明了S波和P波的全角度吸收。我们还发现，在中红外到远红外波段的任何波长处都可能出现超灵敏的强吸收。这些现象对生物传感、完美滤波器和波导非常有益。
