Lin, HaoyangHuang, ZhaoKan, RuifengZheng, HuadanLiu, YihuaLiu, BinDong, LinpengZhu, WenguoTang, JieyuanYu, JianhuiChen, ZheTittel, Frank K.2020-02-142020-02-142019Lin, Haoyang, Huang, Zhao, Kan, Ruifeng, et al.. "Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy." <i>Sensors,</i> 19, no. 23 (2019) MDPI: https://doi.org/10.3390/s19235240.https://hdl.handle.net/1911/108064A novel quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a micro quartz tuning fork (QTF) is reported. As a photoacoustic transducer, a novel micro QTF was 3.7 times smaller than the usually used standard QTF, resulting in a gas sampling volume of ~0.1 mm3. As a proof of concept, water vapor in the air was detected by using 1.39 μm distributed feedback (DFB) laser. A detailed analysis of the performance of a QEPAS sensor based on the micro QTF was performed by detecting atmosphere H2O. The laser focus position and the laser modulation depth were optimized to improve the QEPAS excitation efficiency. A pair of acoustic micro resonators (AmRs) was assembled with the micro QTF in an on-beam configuration to enhance the photoacoustic signal. The AmRs geometry was optimized to amplify the acoustic resonance. With a 1 s integration time, a normalized noise equivalent absorption coefficient (NNEA) of 1.97 × 10−8 W·cm−1·Hz−1/2 was achieved when detecting H2O at less than 1 atm.engThis is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedJournal articlequartz tuning forkphotoacoustic spectroscopyquartz-enhanced photoacoustic spectroscopyacoustic detection modulesensors-19-05240https://doi.org/10.3390/s19235240