Acoustic microresonator based in-plane quartz-enhanced photoacoustic spectroscopy sensor with a line interaction mode

An acoustic microresonator (AmR) based in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) sensor with a line interaction mode is proposed for what is believed to be the first time. The interaction area for the acoustic wave of the proposed AmR, with a slotted sidewall, is not limited to a point of the quartz tuning fork (QTF) prongs, but extends along the whole plane of the QTF prongs. Sixteen types of AmRs are designed to identify the best parameters. Water vapor (H2O) is chosen as the analyte to verify the reported method. The results indicate that this AmR for IP-QEPAS with a line interaction mode not only provides a high signal level, but also reduces the thermal noise caused by the laser directly illuminating the QTF. Compared with standard IP-QEPAS without an AmR, the minimum detection limit (MDL) is improved by 4.11 times with the use of the technique proposed in this study. (C) 2022 Optica Publishing Group

Automated summary

An acoustic microresonator (AmR) based in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) sensor with a line interaction mode is proposed for the first time. The proposed AmR extends the interaction area for the acoustic wave along the whole plane of the quartz tuning fork (QTF) prongs. Sixteen types of AmRs are designed to identify the best parameters, and water vapor (H2O) is chosen as the analyte for verification. The results show that the AmR with a line interaction mode not only provides a high signal level but also reduces thermal noise, improving the minimum detection limit (MDL) by 4.11 times compared to standard IP-QEPAS without an AmR.