2024/08/21 by M. Fisicaro, T. A. Steenbergen, Fisicaro, M. +7 · 1 citation
Earth and Planetary Sciences · Engineering · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Geophysical Methods and Applications #Optics (physics.optics) #Quantum Physics (quant-ph) #Ultrasonics and Acoustic Wave Propagation #Underwater Acoustics Research
paper · pdf · doi:10.48550/arxiv.2408.11630
openalex publication_date 2024/08/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Full characterization of surface acoustic wave (SAW) devices requires imaging the spatial distribution of the acoustic field, which is not possible with standard all-electrical measurements where an interdigital transducer (IDT) is used as a detector. Here we present a fiber-based scanning Michelson interferometer employing a strongly focused laser beam as a probe. Combined with a heterodyne circuit, this setup enables frequency- and spatially-resolved measurements of the amplitude and phase of the SAW displacement. We demonstrate this by investigating a 1 GHz SAW cavity, revealing the presence of frequency-overlapping transverse modes, which are not resolved with an all-electrical measurement. The frequency overlap of these transverse modes leads to mode superpositions, which we analyze by quadrature decomposition of the complex acoustic field.