Light funneling into localized acoustic graphene plasmons for extreme infrared and terahertz field enhancement and confinement

Area of Science:

• Photonics and Nanotechnology
• Condensed Matter Physics

Background:

• Deep subwavelength-scale confinement is vital for advanced applications like molecular sensing and optoelectronics.
• Efficient light-matter interaction requires enhanced field confinement and enhancement.

Purpose of the Study:

• To report the excitation of localized acoustic graphene plasmons (LAGPs) using a metal slit antenna.
• To investigate the light funneling effect for enhanced light-matter interaction in the infrared and terahertz regimes.

Main Methods:

• Excitation of LAGPs in a nanometer-thick graphene layer using a metal slit antenna.
• Analysis of broad-band excitation characteristics and mode tunability.
• Application of temporal coupled mode theory for elucidating findings.

Main Results:

• Achieved strong field enhancement and confinement of light via the funneling effect.
• Demonstrated adjustable excitation modes based on structural symmetry.
• Identified critical influence of device periodicity and graphene electron relaxation time on local field intensities.

Conclusions:

• LAGPs offer significantly improved field confinement and enhancement compared to non-localized plasmons.
• The metal slit antenna approach provides a promising route for robust light-matter interaction.
• Potential applications in infrared and terahertz sensing and optoelectronics.