Fig. 4: Optical resonance frequency shift for different input power (converted to cavity photon numbers on resonance).
From: Integrated optical-readout of a high-Q mechanical out-of-plane mode
a Reflection spectrum when sweeping the laser from short wavelength to long wavelength. Dashed lines are fits to extract the frequency shift, and the results are plotted in (b). A linear fit is performed to extract the coefficient for the optical resonance tuning, which is used to obtain the bistability bound. The gray dashed line marks the maximal frequency shift above which optical bistability occurs
