Yi Hongming, Chen Weidong, Sun Shanwen, Liu Kun, Tan Tu, Gao Xiaoming
Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Science, Hefei 230031, China.
Opt Express. 2012 Apr 9;20(8):9187-96. doi: 10.1364/OE.20.009187.
A novel spectrophone sensor prototype consisting of a T-shaped acoustic microresonator (T-mR) in off-beam quartz-enhanced photoacoustic spectroscopy (T-mR QEPAS) is introduced for the first time. Its performance was evaluated and optimized through an acoustic model and experimental investigation via detection of water vapor in the atmosphere. The present work shows that the use of T-mR in QEPAS based sensor can improve the detection sensitivity by a factor of up to ~30, compared with that using only a bare QTF. This value is as high as that obtained in a conventional "on-beam" QEPAS, while keeping the advantages of "off-beam" QEPAS configuration: it is no longer necessary to couple excitation light beam through the narrow gap between the QTF prongs. In addition, the T-mR is really suitable for mass production with high precision.
