Patimisco, PietroSampaolo, AngeloGiglio, Marilenadello Russo, StefanoMackowiak, VerenaRossmadl, HubertCable, AlexTittel, Frank K.Spagnolo, Vincenzo2019-12-122019-12-122019Patimisco, Pietro, Sampaolo, Angelo, Giglio, Marilena, et al.. "Tuning forks with optimized geometries for quartz-enhanced photoacoustic spectroscopy." <i>Optics Express,</i> 27, no. 2 (2019) Optical Society of America: 1401-1415. https://doi.org/10.1364/OE.27.001401.https://hdl.handle.net/1911/107879We report on the design, realization, and performance of novel quartz tuning forks (QTFs) optimized for quartz-enhanced photoacoustic spectroscopy (QEPAS). Starting from a QTF geometry designed to provide a fundamental flexural in-plane vibrational mode resonance frequency of ~16 kHz, with a quality factor of 15,000 at atmospheric pressure, two novel geometries have been realized: a QTF with T-shaped prongs and a QTF with prongs having rectangular grooves carved on both surface sides. The QTF with grooves showed the lowest electrical resistance, while the T-shaped prongs QTF provided the best photoacoustic response in terms of signal-to-noise ratio (SNR). When acoustically coupled with a pair of micro-resonator tubes, the T-shaped QTF provides a SNR enhancement of a factor of 60 with respect to the bare QTF, which represents a record value for mid-infrared QEPAS sensing.eng© 2019 Optical Society of America under the terms of the OSA Open Access Publishing AgreementJournal articleoe-27-2-1401https://doi.org/10.1364/OE.27.001401