Topological scattering singularities and embedded eigenstates for polarization control and sensing applications
Abstract
Epsilon-near-zero and epsilon near-pole materials enable reflective systems supporting a class of symmetry-protected and accidental embedded eigenstates (EEs) characterized by a diverging phase resonance. Here we show that pairs of topologically protected scattering singularities necessarily emerge from EEs when a non-Hermitian parameter is introduced, lifting the degeneracy between oppositely charged singularities. The underlying topological charges are characterized by an integer winding number and appear as phase vortices of the complex reflection coefficient. By creating and annihilating them, we show that these singularities obey charge conservation, and provide versatile control of amplitude, phase, and polarization in reflection, with potential applications for polarization control and sensing.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 28, 2021
- Source ID
- 10.1364/prj.424247
Entities
People
- Alex Krasnok
- Andrea Alù
- Nikolina Janković
- Zarko Sakotic
Organizations
- Air Force Office of Scientific Research
- City University of New York
- Horizon 2020
- National Science Foundation
- Simons Foundation
- United States Department of Defense
- University of Novi Sad