Fig. 2: Acousto-optic coupling between the surface acoustic waves and photonic BIC modes that are circulating and resonating inside the photonic microcavity.
From: Acousto-optic modulation of photonic bound state in the continuum
a Illustration of the interaction between the SAW travelling along the y direction and the photonic BIC mode travelling along the x direction in the waveguide. The simulated modal field (|E|) of the BIC mode is superimposed onto the structure profile. A large overlap integral of the SAW mode and the photonic BIC mode yields strong acousto-optic coupling. b Illustration of an SAW propagating across a BIC waveguide (upper panel) and an etched waveguide (lower panel). The etched waveguide causes reflection and scattering of the incident SAW, but the BIC waveguide does not.
