Modulation of high quality factors in rolled-up microcavities

Abstract

We systematically investigate the evolution of resonant modes in a rolled-up microcavity as the overlap length between structural notches increases, which presents a modulation behavior for high $Q$ factors. The resonant modes in the rolled-up microcavity display a deterministic mode chirality, which is well correlated to the $Q$ factor. We derive a two-mode non-Hermitian Hamiltonian to clarify these unusual findings. It reveals that strong resonant interactions of scattered waves between the structural notches are responsible for the high mode chirality (thus high $Q$ factor) and its modulation behavior in rolled-up microcavities.