Dispersive and dissipative optomechanical coupling in heterogeneously integrated 2D photonic crystal system

We report on optomechanical effects in 2D photonic crystal defect cavities coupled to integrated silicon waveguides of different widths. Mechanical modes are observed systematically on a chip scale. By tuning the excitation laser wavelength, we observe optical spring effects. We extract optomechanical coupling coefficients and demonstrate the dispersive and dissipative nature of optomechanical coupling. Their relative contribution can be controlled by modifying the access waveguide width, thereby paving the way for a control of optomechanical coupling on the wafer level.