A quartz-enhanced photoacoustic spectroscopy sensor for measurement of water vapor concentration in the air*
Gong Ping, Xie Liang†, Qi Xiao-Qiong, Wang Rui, Wang Hui, Chang Ming-Chao, Yang Hui-Xia, Sun Fei, Li Guan-Peng
Fig. 2. The ADM architectures with and without the microresonators: a the basic ADM architecture consists of a fiber, a Grin lens, and a QTF; b the developed ADM architecture with a pair of microresonators. The Grin lens and the microresonators are in alignment and perpendicular to the QTF plane.