Scanning Optomechanical Enhanced BF-QEPAS for Ultrafast Gas Sensing

Traditional beat-frequency quartz-enhanced photoacoustic spectroscopy (BF-QEPAS) is constrained by short energy accumulation time and the necessity of attenuation cycles, resulting in weaker signals and longer measurement cycles. In this work, we propose a novel scanning optomechanical enhanced (SOE-) BF-QEPAS technique to achieve ultrafast gas detection. By periodically scanning the modulation signal, we supplement excitation energy before the attenuation of the tuning fork’s vibrational energy, thereby optimizing energy accumulation efficiency. For the first time, we introduce a comprehensive quality factor K to evaluate the integrated performance of the system in terms of energy efficiency and signal-to-noise ratio (SNR). After parameter optimization, the SNR demonstrated a 1.88-fold improvement compared to conventional BF-QEPAS, while the response speed increased by 200–400 times.