Transformational plasmonics: cloak, concentrator and rotator for SPPs.

Area of Science:

• * Electromagnetism
• * Optics
• * Condensed Matter Physics

Background:

• * Surface plasmon polaritons (SPPs) are electromagnetic waves confined to the interface between a conductor and a dielectric.
• * Anisotropic media exhibit direction-dependent optical properties, complicating SPP behavior.
• * Transformation optics provides a framework for designing optical devices by manipulating spacetime geometry.

Purpose of the Study:

• * To adapt transformation optics tools for analyzing SPPs in anisotropic media.
• * To elucidate the role of anisotropic permittivity and permeability tensors in SPP dispersion relations.
• * To demonstrate the application of this framework to design SPP-based optical devices.

Main Methods:

• * Applying transformation optics principles to the interface of two anisotropic media with opposite permittivity signs.
• * Deriving the effective permittivity and permeability tensors from coordinate transformations.
• * Analyzing the resulting dispersion relation for SPP propagation.

Main Results:

• * Identified specific entries of anisotropic tensors governing SPP propagation.
• * Established a direct link between material anisotropy and SPP behavior.
• * Successfully applied the methodology to conceptualize SPP invisibility cloaks, concentrators, and rotators.

Conclusions:

• * Transformation optics is a powerful tool for manipulating SPPs in anisotropic environments.
• * Understanding anisotropic tensor properties is crucial for designing advanced plasmonic devices.
• * This work opens avenues for novel nanoscale optical components and functionalities.