Fig. 1. Schematic diagram of a piezo-optomechanical transducer with a TFLN-ChG heterogeneous OMC cavity coupled by a wavelength-scale mechanical waveguide.

Fig. 2. (a) Effects of tLN on g for both fundamental TE and TM modes in the heterogeneous OMC. (b) Variations of the g along the different in-plane orientations in X-cut TFLN with respect to the heterogeneous OMC. (c) Effects of the tChG on g for both fundamental TE and TM modes in the heterogeneous OMC. (d) Variations of the optical Q factors and resonant wavelengths with the increase of the tChG.

Fig. 3. (a) Photonic band of the TM modes corresponding to the mirror region in heterogeneous OMC around the frequency of 200 THz. (b) Phononic band of y-symmetric acoustic modes corresponding to the mirror region in heterogeneous OMC around the frequency of 1.11 GHz. The arrow indicates the cross point between the guided L0 mode (blue line) and excited breathing mode in the heterogeneous OMC. (c) Normalized Ez component of the optical defect mode. (d) Normalized displacement field of the acoustic defect mode.

Fig. 4. Phononic bands of guided acoustic modes corresponding to (a) the narrow XZ LN mechanical waveguide and (b) the initiating terminal of the TFLN-ChG heterogeneous mechanical waveguide at around 1 GHz in heterogeneous piezo-optomechanical transducer. Mode fractions of guided acoustic modes corresponding to (c) the narrow XZ LN mechanical waveguide and (d) the initiating terminal of the TFLN-ChG mechanical waveguide in heterogeneous transducer.

Fig. 5. Simulated results of the guided acoustic modes in the heterogeneous piezo-optomechanical transducer. (a) Excitation and propagation of the SH0 mode in the transducer. (b) Excitation of the breathing mode in heterogeneous OMC cavity coupled by a wavelength-scale mechanical waveguide. (c) Zoomed-in picture representing the conversion between the SH0 and L0 modes near the TFLN-ChG heterogeneous mechanical waveguide.

Fig. 6. Four power orthogonal bases in the heterogeneous mechanical waveguide at 1.15 GHz. The color represents the dominant displacement field component, and the black arrow represents the direction in which the particle vibrates.

Table 1. Parameters of the Heterogeneous OMC Cavity Coupled by a Wavelength-Scale Mechanical Waveguide