Transforming Space with Non-Hermitian Dielectrics.

Area of Science:

• Photonics
• Metamaterials
• Optical Engineering

Background:

• Coordinate transformations are key to manipulating light flow for phenomena like optical cloaking.
• Existing methods often link isotropic materials with conformal transformations, limiting practical applications due to material constraints (e.g., refractive indices below unity).

Purpose of the Study:

• To explore the connection between nonconformal distortions of optical space and the refractive index of isotropic non-Hermitian media.
• To overcome the limitations of refractive indices below unity in transformation optics.
• To design novel optical cloaking devices.

Main Methods:

• Investigating the relationship between nonconformal coordinate transformations and complex refractive index distributions in non-Hermitian materials.
• Developing a theoretical framework linking non-Hermitian photonics with transformation optics.
• Applying the derived principles to design a broadband unidirectional dielectric cloak.

Main Results:

• Demonstrated that nonconformal distortions are intrinsically linked to the complex refractive index of isotropic non-Hermitian media.
• Showcased a method to circumvent the need for refractive indices below unity.
• Successfully designed a broadband unidirectional dielectric cloak utilizing nonconformal transformations.

Conclusions:

• The study bridges two-dimensional transformation optics and non-Hermitian photonics.
• The findings offer new pathways for designing advanced optical devices, including cloaks, by leveraging non-Hermitian properties.
• This work expands the toolkit for manipulating light with metamaterials and isotropic media.