Fig. 1. Cross section of the poly-crystalline AlN films^［25-26］

Fig. 2. Morphotropic phase boundary in a ferroelectric PZT system（PbZrO₃-PbTiO₃）^［41］

Fig. 3. Characterization of orthorhombic ferroelectric phases in thin-film HfO₂^［42］

Fig. 4. Schematic diagram of lithium niobate crystal structure^［57］

Fig. 5. Schematic diagram and advantages of the piezoelectric effect^［10］

Fig. 6. Low-power piezo-optomechanically tuning device based on PZT^{［62-64，67］}

Fig. 7. Low-power piezo-optomechanically tuning device based on AlN^{［65，66］}

Fig. 8. Low-power piezo-optomechanically tuning device based on Zr-doped HfO₂^［8］

Fig. 9. AlN acoustic-optic modulator^［71-74］

Fig. 10. LN Acoustic-Optic Modulator（AOM）^［75-82］

Fig. 11. AlN piezo-optomechanical actuator chip and its computing applications^［10］

Fig. 12. AlN piezo-optomechanical actuator chip and its optical isolator application^［66］

Fig. 13. Acoustic-optic modulator application^［84-86］