MEMS-Driven Electrically Reconfigurable Platform for Photonic Quasi-Bound States in the Continuum

Bound states in the continuum (BICs), while highly sensitive to structural parameters and requiring precise geometric control, are limited in practical applications like sensors due to their static nature and fixed frequency design. Herein, we experimentally realize, for the first time, a reconfigurable mirror-coupled quasi-BIC in the mid-infrared region by using electrically driven MEMS technology. Specifically, we tune the spacing between mirror-coupled resonators to reconfigure the quasi-BIC. We demonstrate the reconfiguration with response times down to μs and a wavelength range up to 400 nm. In the gas sensing demonstration, the electrically driven reconfiguration improves the detuning between the BIC platform and the absorption of target gas molecules, resulting in a 2.9- fold enhancement of the sensing signal. Our work provides a methodology for the precise geometric control of photonic BIC, broadening its application in real-world scenarios.