Abstract
Bound states in a continuum in periodic photonic structures can be described as topological defects in the k-space. These vortices can migrate within the Brillouin zone when the geometrical parameters of the system vary. In this study, we focus on the migration of the polarization vortex across the light line, from the radiation continuum to the waveguide mode domain. We found that during this transition, the far-field polarization vortex transforms into a near-field vortex. This near-field vortex is characterized by an enhanced localization of the evanescent field due to the vanishing fundamental Fourier harmonic of the Bloch amplitude. This mechanism can be used to improve polaritonic devices and optical sensors based on all-dielectric metasurfaces by increasing the overlap between optical modes and 2D excitons or thin layers of bio-analytes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.