Browsing by Author "Kan, Ruifeng"

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    Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy
    (MDPI, 2019) Lin, Haoyang; Huang, Zhao; Kan, Ruifeng; Zheng, Huadan; Liu, Yihua; Liu, Bin; Dong, Linpeng; Zhu, Wenguo; Tang, Jieyuan; Yu, Jianhui; Chen, Zhe; Tittel, Frank K.
    A 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.
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    Quartz-enhanced photoacoustic spectroscopy exploiting a fast and wideband electro-mechanical light modulator
    (Optical Society of America, 2020) Zheng, Huadan; Zheng, Huadan; Liu, Yihua; Lin, Haoyang; Kan, Ruifeng; Kan, Ruifeng; Dong, Lei; Dong, Lei; Zhu, Wenguo; Fang, Junbin; Yu, Jianhui; Yu, Jianhui; Tittel, Frank K.; Chen, Zhe
    A quartz-enhanced photoacoustic spectroscopy (QEPAS) gas sensor exploiting a fast and wideband electro-mechanical light modulator was developed. The modulator was designed based on the electro-mechanical effect of a commercial quartz tuning fork (QTF). The laser beam was directed on the edge surface of the QTF prongs. The configuration of the laser beam and the QTF was optimized in detail in order to achieve a modulation efficiency of ∼100%. The L-band single wavelength laser diode and a C-band tunable continuous wave laser were used to verify the performance of the developed QTF modulator, respectively, realizing a QEPAS sensor based on amplitude modulation (AM). As proof of concept, the AM-based QEPAS sensor demonstrated a detection limit of 45 ppm for H2O and 50 ppm for CO2 with a 1 s integration time respectively.