title: Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism.
abstract: A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS) system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR) was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA) of 5.8 × 10(-8) W·cm(-1)·Hz(-1/2) was achieved for water vapor detection in the atmosphere.
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. Liuyongning1990@163.com.
authors: Yongning
authors: Y
authors: Liu
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. changjun@sdu.edu.cn.
authors: Jun
authors: J
authors: Chang
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. lianjie@sdu.edu.cn.
authors: Jie
authors: J
authors: Lian
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. zhaojunliu@sdu.edu.cn.
authors: Zhaojun
authors: Z
authors: Liu
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. iamwq1989@gmail.com.
authors: Qiang
authors: Q
authors: Wang
authors: School of Information Science and Engineering, Shandong University, Jinan 250100, China. qinzengguang@sdu.edu.cn.
authors: Zengguang
authors: Z
authors: Qin
keywords: DFB-LD; QEPAS; gas detection; right-angle prism