Realization of Bound state In the Continuum induced by vertical symmetry breaking in photonic lattice

TL;DR

This paper reports the experimental realization of a new type of Bound State in the Continuum (BIC) in photonic crystal slabs, induced by vertical symmetry breaking, enabling tailored photonic states for non-Hermitian photonics.

Contribution

The study demonstrates experimentally and theoretically a novel BIC induced by vertical symmetry breaking, expanding control over photonic states in complex plane.

Findings

BIC observed near the anticrossing point of hybridized resonances

Experimental results match numerical simulations and analytical models

Vertical symmetry breaking enables dispersion engineering of photonic states

Abstract

We demonstrate experimentally a new type of Bound state In the Continuum (BIC) which is induced by the vertical symmetry breaking of a photonic crystal slab. Such BIC emerges from the hybridization between Bloch resonances of opposite parities once the vertical symmetry is broken, and is observed in the vicinity of the anticrossing point at the lower hybrid band of the energy-momentum diagram. All experimental results are nicely reproduced by numerical simulations, and in good agreement with an analytical model based on Friedrich-Wintgen framework. Together with the possibility of dispersion engineering by vertical symmetry breaking, our results open the way to tailor photonic states in the entire complex plane to study non-hermitian photonics.