Non-Hermitian metasurfaces for the best of plasmonics and dielectrics
Abstract
Materials and their geometry make up the tools for designing nanophotonic devices. In the past, the real part of the refractive index of materials has remained the focus for designing novel devices. The absorption, or imaginary index, was tolerated as an undesirable effect. However, a clever distribution of imaginary index of materials offers an additional degree of freedom for designing nanophotonic devices. Non-Hermitian optics provides a unique opportunity to take advantage of absorption losses in materials to enable unconventional physical effects. Typically occurring near energy degeneracies called exceptional points, these effects include enhanced sensitivity, unidirectional invisibility, and non-trivial topology. In this work, we leverage plasmonic absorption losses (or imaginary index) as a design parameter for non-Hermitian, passive parity-time symmetric metasurfaces. We show that coupled plasmonic-photonic resonator pairs, possessing a large asymmetry in absorptive losses but balanced radiative losses, exhibit an optical phase transition at an exceptional point and directional scattering. These systems enable new pathways for metasurface design using phase, symmetry, and topology as powerful tools.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 24, 2021
- Source ID
- 10.1364/ome.428469
Entities
People
- Alexander Hwang
- Chloe F Doiron
- Frank Yang
- Gururaj V. Naik
Organizations
- Army Research Office
- National Science Foundation
- Rice University