全光型石英增强光声光谱

设计并演示了一种全光型石英增强光声光谱技术, 该技术在传统的石英增强光声光谱系统中增加了另一束探测光束, 把与气体浓度成正比的石英晶振振臂的振动幅值转化为探测光束的强度变化, 实现了探测气体处无电子元件的全光学系统. 如此的设计使该系统具有较强的抗电磁干扰能力和非常小的传感头体积, 能够用于探测空间受限或探测环境恶劣的情况下, 并实现远距离探测. 在这种配置下, 探测大气压下的水汽, 获得的噪声等效吸收系数为1.13×10^-6 cm^-1W/√Hz. 进一步讨论了优化系统和提升其探测灵敏度的途径.关键词：石英增强光声光谱音叉式石英晶振气体传感

All optical quartz-enhanced photoacoustic spectroscopy

A trace gas sensor based on all optical quartz-enhanced photoacoustic spectroscopy (QEPAS) is designed and demonstrated. An extra detection light beam is added to the traditional QEPAS setup to convert the amplitude of vibration of the quartz tuning fork, which is proportional to the concentration of the target gas, into the variation of the detection light intensity. As a result, there are not any electrical components near the measurement position. Such a design makes it immune to electromagnetic interference and provides a compact sensor head, which can be used in a tiny space or an adverse environment. Using the new setup to measure the water concentration in air, the obtained noise equivalent absorption coefficient is 1.13×10^-6 cm^-1W/√Hz. The approaches to further optimizing the system and improving the sensitivity are also discussed in detail.
Keywords：quartz-enhanced photoacoustic spectroscopyquartz tuning forkgas sensor