Fig. 2: Phononic and photonic resonances of the optomechanical ring (OMR).

a The bottom layer is an optical image of the optomechanical integrated circuit (OMIC) device. Scale bar: 100 μm. The middle and the top layers are schematic illustrations of the phononic and photonic circuitry, respectively, of the OMIC. b Broadband |S₁₁| spectrum of one of the IDTs measured at 4 K (blue) and room temperature (black). c Normalized optical transmission spectrum of the OMR. The inset shows the zoomed-in resonance at 1571.7 nm, the red line is the Lorentzian fitting of the resonance, and the open circles are the measured data. The loaded optical quality factor \({Q}_{{ol}}=7.5\times {10}^{4}\). d Time-gated transmission spectrum |S₂₁| of the OMR measured at 4 K. The spacing of the gray dashed lines denote the FSR (5.5 MHz) of the phononic resonances around 2.56 GHz. The inset shows the zoomed-in |S₂₁| at 2.56 GHz, the red line is the Lorentzian fitting of the resonance, and the open circles are the measured data. The loaded acoustic quality factor \({Q}_{{al}}=2300\).