We present a perfect graphene absorber with compound waveguide grating at near infrared. The analytical approach is mainly based on the coupled leaky mode theory, which turns the design of absorber to finding out the required leaky modes supported by the grating structure. Perfect absorption occurs only when the radiative loss of the leaky mode match the intrinsic absorption loss, which is also named as critical coupling condition. Furthermore, we also demonstrate that the critical coupling of the system can be robustly controlled, and the perfect absorption wavelength can be easily tuned by adjusting the parameters of compound waveguide grating.
Hu Jinhua, Fu Jia, Liu Xiuhong, Ren DanPing, Zhao JiJun , Huang Yongqing. Perfect absorption in a monolayer graphene at near-infrared using a compound waveguide grating by robust critical coupling[J]. Chinese Optics Letters, 2019, 17(1): .
