Quantum mechanics

Engineering

Materials science

Refractive index

Graphene

Coupling (piping)

Impedance matching

Absorption (acoustics)

Metamaterial

Absorbance

Tunable metamaterials

Electrical impedance

Physics

Nanotechnology

Metamaterial absorber

Optics

Electronic engineering

Composite material

Sensitivity (control systems)

Figure of merit

Optoelectronics

Nanomaterials

By means of critical coupling and impedance matching theory, we have numerically simulated the perfect absorption of monolayer graphene. Through the critical coupling effect and impedance matching, we studied a perfect single-band absorption of the monolayer graphene and obtained high quality factor (Q-factor = 664.2) absorption spectrum which has an absorbance close to 100% in the near infrared region. The position of the absorption spectrum can be adjusted by changing the ratio between the radii of the elliptic cylinder air hole and the structural period. The sensitivity of the absorber can be achieved S = 342.7 nm/RIU (RIU is the per refractive index unit) and FOM = 199.2 (FOM is the figure of merit), which has great potential for development on biosensors. We believe that our research will have good application prospects in graphene photonic devices and optoelectronic devices.

High Quality Factor, High Sensitivity Metamaterial Graphene—Perfect Absorber Based on Critical Coupling Theory and Impedance Matching