End-to-end hardware modeling and sensitivity optimization of photoacoustic signal readout chains

Photoacoustic imaging critically depends on the sensitivity of its acoustic readout chain, yet system-level optimization beyond the transducer remains insufficiently understood. Here, we present an end-to-end hardware model for photoacoustic signal readout chains by analytically rederiving the Krimholtz, Leedom, and Matthaei (KLM) model and extending it to include cable parasitics and complex receiver impedance. The model reveals how element area (EA), cable length (CL), and receiver impedance (RI) jointly govern detection sensitivity, bandwidth, and signal-to-noise ratio, which is validated experimentally with errors below 5%. Beyond sensitivity optimization, the model also provides insight into waveform distortion mechanisms in practical systems, identifying radial resonance as the source of low-frequency ringing artifacts. This work provides a practical theoretical framework for sensitivity optimization and artifact-aware design in photoacoustic systems.