Strong optomechanical coupling in chain-like waveguides of silicon nanoparticles with quasi-bound states in the continuum

Abstract

We propose and demonstrate that strong optomechanical coupling can be achieved in a chain-like waveguide consisting of silicon nanorods. By employing quasi-bound states in the continuum and mechanical resonances at a frequency around 10 GHz, the optomechanical coupling rate can be above 2 MHz and surpass most microcavities. We have also studied cases with different optical wave numbers and size parameters of silicon, and a robust coupling rate has been verified, benefiting the experimental measurements and practical applications. The proposed silicon chain-like waveguide of strong optomechanical coupling may pave new ways for research on photon-phonon interaction with microstructures.