Visualization of Acoustic Power Flow in Suspended Thin-film Lithium Niobate Phononic Devices

Understand

We report direct visualization of gigahertz-frequency acoustic waves in lithium niobate phononic circuits.

• Primary propagation parameters, such as the power flow angle (PFA) and propagation loss (PL), are measured by transmission-mode microwave impedance microscopy (TMIM).
• Using fast Fourier transform, we can separately analyze forward and backward propagating waves and quantitatively evaluate the propagation loss.
• Our work provides insightful information on the propagation, diffraction, and attenuation in piezoelectric thin films, which is highly desirable for designing and optimizing phononic devices for microwave signal processing.