All-optical reconfigurable photonic crystal-microring hybrid cavities with high-efficiency tuning via the mechanical...

All-optical control of silicon photonic integrated devices is crucial for on-chip applications such as signal processing, computing, and switching. A key limitation of current integrated devices is high power consumption, stemming from the weak nonlinear effects of silicon. An alternative nonlinear effect in deformable platforms is the mechanical Kerr effect (MKE), which arises from the optical gradient force (OGF) generated by highly localized optical fields that can deflect freestanding waveguides near a dielectric substrate. In this work, we present a hybrid optomechanical cavity design, driven by OGF, which integrates a compact microring resonator (MRR) with a radius of 10.08 µm and a quadratically tapered photonic crystal nanobeam cavity (PCNC). This design results in two distinct types of resonant modes, enabling mode-dependent wavelength routing. Due to strong localization and intensity enhancement, the tuning range and efficiency are significantly improved compared to conventional MRRs. An experimental 1.98 nm redshift is achieved in the probe PCNC mode, corresponding to a tuning efficiency of 142 GHz/mW. Additionally, substantial mode splitting is observed due to the mode-dependent tuning capability of the device. This design holds great potential for wavelength routing applications, particularly in advanced all-optical tunable optical filtering systems.