Fractal H-shaped plasmonic nanocavity

Area of Science:

• Nanophotonics
• Metamaterials
• Fractal Geometry

Background:

• Fractal geometry offers unique properties for nanostructure design.
• Localized enhanced fields are crucial for advanced optical devices.
• Multiband functionality is desirable for versatile applications.

Purpose of the Study:

• To design a novel infrared quasi-3D nanocavity with localized enhanced fields.
• To achieve multiband resonant frequencies using fractal geometry.
• To explore potential applications in nanoscale devices.

Main Methods:

• Utilized complementary fractal geometry for nanostructure design.
• Employed the finite difference time domain (FDTD) method for simulations.
• Applied the effective medium method to retrieve material properties.

Main Results:

• Achieved a localized enhanced electric field within the nanocavity.
• Demonstrated multiband resonant frequencies at two distinct frequencies.
• Observed field intensity enhancement up to 60 times the incident light.
• Identified surface plasmon hybridization as key to field enhancement.

Conclusions:

• The designed fractal nanocavity exhibits strong localized field enhancement and multiband properties.
• The loss factor in permittivity significantly contributes to the enhanced field.
• The nanocavity holds promise for surface-enhanced Raman scattering (SERS) and other nanoscale applications.