Optical Fermi level-tuned plasmonic coupling in a grating-assisted graphene nanoribbon system

Area of Science:

• Metamaterials
• Plasmonics
• Graphene photonics

Background:

• Graphene's unique optical properties offer potential for novel photonic devices.
• Controlling light-matter interactions in graphene-based structures is crucial for advanced applications.
• Metamaterials provide a platform for manipulating electromagnetic waves beyond natural material limits.

Purpose of the Study:

• To propose and theoretically investigate a novel graphene-based grating-coupled metamaterial structure.
• To demonstrate voltage-tunable optical responses, including plasmon-induced transparency.
• To evaluate the structure's suitability for plasmonic optical reflectors and slow light applications.

Main Methods:

• Theoretical analysis of a grating-coupled bilayer graphene metamaterial.
• Investigation of light-graphene interaction and plasmon polariton excitation.
• Simulation of optical response modulation via Fermi level tuning using applied voltage.

Main Results:

• The proposed structure exhibits plasmon-induced transparency due to destructive interference between bright and dark modes.
• Optical response is effectively controlled by the graphene Fermi level, tunable via applied voltage.
• High reflection efficiency and a group delay of 0.3 ps were achieved, indicating slow light performance.

Conclusions:

• The novel graphene metamaterial structure offers a simple yet effective design for tunable optical devices.
• The demonstrated plasmon-induced transparency and efficient reflection highlight its potential for optical reflectors.
• The device's slow light capabilities suggest contributions to advanced optical signal processing and delay applications.