Characterization of Shear Horizontal Waves Using a 1D Laser Doppler Vibrometer

Area of Science:

• Acoustics
• Materials Science
• Wave Physics

Background:

• Shear horizontal surface acoustic waves (SH-SAW) are crucial for various sensor applications.
• Accurate detection and characterization of SH-SAW are essential for device performance.
• Existing methods for SH-SAW detection can be complex or limited in scope.

Purpose of the Study:

• To develop a non-contact, precise technique for SH-SAW detection.
• To enable the estimation of in-plane displacement fields and surface confinement.
• To validate the proposed method through simulation and experimental verification.

Main Methods:

• Utilizing a one-dimensional laser-based Doppler vibrometer to measure out-of-plane surface deformation.
• Employing finite element analysis (FEA) for theoretical validation.
• Experimental demonstration using a Bleustein-Gulyaev resonator.

Main Results:

• The laser-based Doppler vibrometer successfully detected SH-SAW.
• The technique accurately estimated the in-plane displacement field based on measured out-of-plane deformation and substrate Poisson ratio.
• The degree of surface confinement (wave decay rate) was also successfully estimated.

Conclusions:

• The developed laser-based Doppler vibrometer technique offers a novel and effective approach for SH-SAW detection.
• This method provides valuable insights into wave propagation characteristics, including displacement and confinement.
• The technique holds promise for advancing the characterization and application of acoustic wave devices.