Wu, HongpengSampaolo, AngeloDong, LeiPatimisco, PietroLiu, XiaoliZheng, HuadanYin, XukunMa, WeiguangZhang, LeiYin, WangbaoSpagnolo, VincenzoJia, SuotangTittel, Frank K.2017-05-122017-05-122015Wu, Hongpeng, Sampaolo, Angelo, Dong, Lei, et al.. "Quartz enhanced photoacoustic H2S gas sensor based on a fiber-amplifier source and a custom tuning fork with large prong spacing." <i>Applied Physics Letters,</i> 107, no. 11 (2015) AIP Publishing LLC: http://dx.doi.org/10.1063/1.4930995.https://hdl.handle.net/1911/94233A quartz enhanced photoacoustic spectroscopy (QEPAS) sensor, employing an erbium-doped fiber amplified laser source and a custom quartz tuning fork (QTF) with its two prongs spaced ∼800 μm apart, is reported. The sensor employs an acoustic micro-resonator (AmR) which is assembled in an “on-beam” QEPAS configuration. Both length and vertical position of the AmR are optimized in terms of signal-to-noise ratio, significantly improving the QEPAS detection sensitivity by a factor of ∼40, compared to the case of a sensor using a bare custom QTF. The fiber-amplifier-enhanced QEPAS sensor is applied to H2S trace gas detection, reaching a sensitivity of ∼890 ppb at 1 s integration time, similar to those obtained with a power-enhanced QEPAS sensor equipped with a standard QTF, but with the advantages of easy optical alignment, simple installation, and long-term stability.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttp://dx.doi.org/10.1063/1.4930995