Abstract

Quartz tuning forks (QTFs) have been successfully employed as piezoelectric optoacoustic transducers in a quartz enhanced photoacoustic spectroscopic sensor (QEPAS) for sensitive and selective gas sensing applications. Stainless tubes are acoustically coupled with the QTF and act as an acoustic micro-resonator (AmR) to confine the acoustic waves and enhance the QEPAS signal [1]. Very recently, we realized custom QTFs with fundamental resonance frequency of a few KHz [2] in order to approach the typical energy relaxation time of gases, while maintaining a high resonator quality factor. However, lowering the fundamental resonance frequency reduces also the overtone frequencies, leading to their use in QEPAS.

© 2017 IEEE