Photoacoustic spectroscopy (PAS), which relies on the detection of absorption-induced acoustic waves, is widely used for gas sensing. This paper summarizes and discusses most of the recent techniques for photoacoustic enhancement throughout the overall process from laser-molecule interaction to acoustic wave detection. Considering the theoretical principle and system composition of PAS gas sensor, we classify photoacoustic enhancing techniques into three aspects. The first one is to enhance the photoacoustic excitation by building up the laser power in terms of the positive proportional relation between the optical power and photoacoustic signal. The second one is to amplify the acoustic strength with various kinds of resonators after the photoacoustic generation. The third approach to further improve the photoacoustic detection is to develop more efficient acoustic transducers, for example, custom tuning fork, cantilever and fiber-optic microphone. Finally, the advantages and limitations of these different techniques are analyzed.

光声光谱 (PAS) 依赖于吸收诱导声波的检测，被广泛用于气体传感。本文总结并讨论了从激光-分子相互作用到声波检测的整个过程中大多数用于光声增强的最新技术。考虑到PAS气体传感器的理论原理和系统组成，我们将光声增强技术分为三个方面。第一个是根据光功率与光声信号之间的正比关系，通过建立激光功率来增强光声激发。二是在光声产生后用各种谐振器放大声强度。进一步改进光声检测的第三种方法是开发更高效的声学换能器，例如定制音叉、悬臂和光纤麦克风。最后，分析了这些不同技术的优点和局限性。