Laser Spectroscopic Sensing Based on an Integrated Piezoelectric Ceramic Acoustic Resonator and Tuning Fork

In this paper, a compact photoacoustic sensing architecture based on the integration of a piezoelectric ceramic acoustic resonator (PCAR) and a piezoelectric ceramic tuning fork (PCTF) is reported for the first time. Benefiting from the combination of acoustic resonance enhancement and piezoelectric conversion, the proposed architecture improves both signal generation and acoustic energy utilization efficiency. By replacing the conventional metal acoustic resonator with a piezoelectric ceramic acoustic resonator, efficient acoustic energy collection and signal combination are achieved. The sensing performance was experimentally validated using C₂H₂. Under the in-plane excitation with the piezoelectric ceramic acoustic resonator (IPE-PCAR) mode, the combined signal amplitude is increased by 67.7% compared with that of the metal acoustic resonator configuration. The sensor exhibits a minimum detection limit (MDL) of 2.93 ppm and a normalized noise-equivalent absorption (NNEA) of 5.41 × 10^–8. This work provides an effective approach for improving acoustic energy utilization and offers a promising strategy for the development of highly integrated, high-performance PAS-based gas sensors.