Energy-efficient all-optical control of optomechanical photonic crystal nanobeam cavities

All-optical control of silicon photonic devices is vital for on-chip signal processing, computing, and switching, but remains limited by silicon's weak nonlinearities and high-power demand. Here, we propose, fabricate, and demonstrate a 1D optomechanical photonic crystal nanobeam utilizing the Mechanical Kerr Effect (MKE), achieving a 6.84 nm wavelength shift with just 1.85 mW input power, corresponding to a record tuning efficiency of 486.5 GHz/mW. The device exhibits fast dynamics, with a 1.25 μs rise time and a 0.24 μs fall time. This approach offers a low-power, tunable platform for integrated photonic functions like switching, routing, and filtering.