Directive giant upconversion by supercritical bound states in the continuum.

ABSTRACT: Photonic bound states in the continuum (BICs), embedded in the spectrum of free-space waves^1,2 with diverging radiative quality factor, are topologically non-trivial dark modes in open-cavity resonators that have enabled important advances in photonics^3,4. However, it is particularly challenging to achieve maximum near-field enhancement, as this requires matching radiative and non-radiative losses. Here we propose the concept of supercritical coupling, drawing inspiration from electromagnetically induced transparency in near-field coupled resonances close to the Friedrich-Wintgen condition². Supercritical coupling occurs when the near-field coupling between dark and bright modes compensates for the negligible direct far-field coupling with the dark mode. Th

SUBMITTER: Schiattarella C 

PROVIDER: S-EPMC10881401 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature