Modeling the Geometry-Acoustics Dependence in Photoacoustic Resonators: A Toroidal Case Study

Area of Science:

• Acoustics
• Optical Engineering
• Physics

Background:

• Photoacoustic sensing (PAS) devices require accurate modeling of resonator behavior.
• Existing models for toroidal resonators lack sufficient accuracy and design guidance.

Purpose of the Study:

• To develop compact, physics-guided analytical models for toroidal photoacoustic resonators.
• To establish relationships between resonator geometry, resonance frequency, and quality factor.

Main Methods:

• Combined finite-element data with reduced-order analytical models.
• Developed a corrected toroidal resonance frequency model including propagation length and thermo-viscous effects.
• Proposed a boundary-layer dissipation model for the quality factor.

Main Results:

• Validated models using 3D printed toroidal resonators.
• Achieved <1% average relative error for resonance frequencies, outperforming existing models.
• Confirmed quality factor trends with minor radius, linking cross-sectional area to acoustic losses.

Conclusions:

• The developed framework offers accurate, interpretable design rules for toroidal photoacoustic resonators.
• Reduces reliance on extensive simulations for initial design estimations.
• Enables optimization of high-performance PAS devices with preserved accuracy.