A novel structure for tunable terahertz absorber based on graphene.

Area of Science:

• Condensed matter physics
• Materials science
• Electromagnetism

Background:

• Graphene's tunable conductivity makes it a promising material for electromagnetic absorbers.
• Existing terahertz absorbers often require complex fabrication or patterned structures.

Purpose of the Study:

• To propose and demonstrate a novel, easily fabricated tunable terahertz absorber based on graphene.
• To achieve fine-tuning of absorption resonances via electrical bias.
• To explore both narrowband and broadband absorption capabilities without graphene patterning.

Main Methods:

• Fabrication of an "uneven dielectric slab structure" using graphene-dielectric stacks and a conductor layer.
• Utilizing bias voltage adjustment to tune conductivity and absorption resonances.
• Characterization of absorber performance under obliquely incident electromagnetic waves.

Main Results:

• Demonstration of both narrowband and broadband tunable terahertz absorbers.
• Achieved convenient fine-tuning of absorption resonances by adjusting bias voltage.
• Observed stable absorption resonances across a wide range of incident angles.

Conclusions:

• The proposed uneven dielectric slab structure offers a simple and effective platform for graphene-based tunable terahertz absorbers.
• The design eliminates the need for patterned graphene, simplifying fabrication.
• The absorber exhibits robust performance with stable resonances under varying incidence angles, suitable for diverse THz applications.