High fabrication-tolerant narrowband perfect graphene absorber based on guided-mode resonance in distributed Bragg reflector.

ABSTRACT: We propose the narrowband perfect absorbers with enormously high fabrication tolerance, which consists of a low-contrast grating and a finite distributed Bragg reflector (DBR) layer with an ultrathin absorbing medium (graphene). It is numerically shown that the proposed perfect absorber outperforms the previously proposed schemes in fabrication tolerance. According to the rigorous coupled wave analysis (RCWA) and coupled mode theory (CMT) fitting, over a considerably wide range of grating width and thickness, the proposed absorber provides a proper ratio of leakage rate to loss rate while preserving resonant condition, so that almost perfect absorption (>99.9%) can be obtained. This result is attributed to the strong electric field confinement in the DBR region rather than the grating laye

SUBMITTER: Lee S 

PROVIDER: S-EPMC6414689 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature