Spherical harmonic-domain acousto-optic tomography for three-dimensional sound-field reconstructiona)

Area of Science:

• Acoustics
• Optical Physics
• Signal Processing

Background:

• Acousto-optic tomography (AOT) is a key technique for high-resolution sound field observation.
• Physical-model-based AOT has improved accuracy and reduced sampling needs.
• Reconstructing 3D outgoing sound waves remains challenging due to mathematical and measurement limitations.

Purpose of the Study:

• To develop a novel method for reconstructing 3D sound fields, addressing limitations of existing AOT techniques.
• To enable accurate mapping of sound waves radiated by sources and scattered by objects in three dimensions.

Main Methods:

• Proposed spherical harmonic-domain AOT, integrating parallel phase-shifting interferometry with spherical wave function expansions.
• Formulated distinct reconstruction problems for radiated and scattered sound fields.
• Employed experimental validation to demonstrate the method's efficacy.

Main Results:

• Successfully reconstructed 3D sound fields radiated by two ultrasonic transducers.
• Successfully reconstructed 3D sound fields scattered by an ellipsoid object.
• Demonstrated the feasibility of the proposed spherical harmonic-domain AOT for complex sound field mapping.

Conclusions:

• Spherical harmonic-domain AOT offers a robust solution for 3D sound field reconstruction.
• The method overcomes previous constraints in mathematical formulation and measurement systems.
• This advancement has significant implications for acoustic research and applications requiring detailed sound field visualization.