Precise control of the surface acoustic wave (SAW) frequency is essential for the reliable operation of high-frequency acoustic devices, which is typically achieved by varying the transducer periodicity $P$. However, the effect of transducer width $L$, or equivalently, the $L/P$ ratio, on frequency remains largely unexplored. Here, we investigate the generation and detection of GHz SAWs using metallic transducers of varying width $L$ but having constant periodicity $P$ fabricated on a nonpiezoelectric silicon wafer. Coherent SAWs are optically excited using near-infrared femtosecond pulses and probed via time-resolved extreme ultraviolet diffraction, enabling simultaneous measurement of first- and second-order SAWs. We find that as $L$ decreases from 410 to 45 nm for constant $P=1000\mathrm{nm}$, the first- and second-order SAW frequencies stiffen by nearly 3% and 6.5%, respectively. The measured stiffening exceeds predictions from finite-element-based linear-elastic eigenvalue analysis by 1% and 1.5%, respectively, thus making the SAW frequency transducer width dependent. The analysis of displacements, strains, and strain gradients indicates that the additional stiffening on decreasing $L$ may arise from large strain gradients at the transducer edges. Importantly, this relatively small change in SAW frequency for a large variation in $L$ establishes transducer width as a sensitive parameter for fine and continuous tuning of SAW frequency by approximately 1%–6% in the vicinity of the desired frequency, enabling precise control beyond what is typically achievable with $P$ alone. Such fine-tuning capability is particularly relevant for applications in radio-frequency signal processing and quantum acoustic systems, where even small deviations can significantly impact device performance.

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• Nanophotonics
• Thermomechanical effects
• Finite-element method
• High-harmonic generation
• Surface acoustic wave
• Ultrafast pump-probe spectroscopy