Electrical Phase Control Based on Graphene Surface Plasmon Polaritons in Mid-infrared

Area of Science:

• Optoelectronics
• Materials Science
• Photonics

Background:

• Phase modulation is crucial for optoelectronic devices like switches and modulators.
• Graphene surface plasmon polaritons (SPPs) offer unique phase modulation properties, including dynamic tunability, low driving voltage, and compact device size.

Purpose of the Study:

• To theoretically and computationally confirm the phase modulation capabilities of graphene SPPs in the mid-infrared spectrum.
• To propose and analyze a novel graphene-based waveguide structure for efficient phase modulation.

Main Methods:

• Theoretical analysis of graphene SPPs.
• Electromagnetic simulations to validate phase modulation performance.
• Design and optimization of a dielectric-graphene-dielectric sandwich waveguide structure.

Main Results:

• Graphene SPPs enable continuous phase shift tuning (0°–360°) across multiple mid-infrared wavelengths.
• The proposed 800 nm dielectric-graphene-dielectric waveguide achieved a 381° phase modulation range at 6.55 µm with a 1 V driving voltage.
• The structure operates at sub-wavelength dimensions, significantly smaller than the operating wavelength.

Conclusions:

• Graphene SPPs are highly effective for phase modulation in the mid-infrared range.
• The developed sub-wavelength waveguide structure shows promise for advanced mid-infrared tunable devices.
• This research paves the way for graphene-based devices for mid-infrared wave-front control applications.