Piezoelectric Ceramic Tuning Fork Enhanced Laser Spectroscopic Sensing

In this paper, a piezoelectric ceramic tuning fork (PCTF) enhanced laser spectroscopic gas sensing technique was reported for the first time, moving beyond the long-standing reliance on conventional quartz tuning forks (QTF). Benefiting from the stronger piezoelectric properties of ceramic materials, the developed PCTFs exhibit superior performance over QTFs. Two high-piezoelectric-coefficient ceramics, PZT-47 and PZT-41, were used to fabricate low-frequency tuning forks (P47 and P41 PCTFs). The performance of these two PCTFs were experimentally validated in piezoelectric ceramic-enhanced photoacoustic spectroscopy (PCPAS), light-induced thermoelastic spectroscopy (LITES), and heterodyne piezoelectric ceramic-enhanced photoacoustic spectroscopy (H-PCPAS) systems. In PCPAS, P47 and P41 PCTFs provide 2.26-fold and 3.81‑fold signal enhancement relative to standard QTFs. With an optimized acoustic micro‑resonator, the P41 PCTF signal is further amplified by 158 times, achieving a minimum detection limit of 0.31 ppm. In LITES, signal improvements reach 2.03 and 3.50 times, respectively. In H-PCPAS, the faster energy dissipation of the P41 PCTF leads to a 1.71-fold improvement in response speed compared with the standard QTF, allowing gas detection to be completed within 1.33 s. This work demonstrates the feasibility of employing piezoelectric ceramics in laser spectroscopic gas sensing, and provides a promising pathway for future material-device co-optimization toward high-performance sensors.