Application of acoustic resonators in photoacoustic trace gas analysis and metrology

TLDR

Acoustic resonators—pipes, cylinders, and spheres—are employed in photoacoustic spectroscopy, with their fundamental properties, laser excitation modes, and signal‑amplification characteristics discussed. The review aims to equip newcomers with guidance for designing and building advanced photoacoustic detectors for trace gas analysis, spectroscopy, and metrology. It details the theory and practice of high‑ and low‑Q resonators, their integration into photoacoustic detection systems, and the associated setup properties and noise characteristics.

Abstract

The application of different types of acoustic resonators such as pipes, cylinders, and spheres in photoacoustics is considered. This includes a discussion of the fundamental properties of these resonant cavities. Modulated and pulsed laser excitation of acoustic modes is discussed. The theoretical and practical aspects of high-Q and low-Q resonators and their integration into complete photoacoustic detection systems for trace gas monitoring and metrology are covered in detail. The characteristics of the available laser sources and the performance of the photoacoustic resonators, such as signal amplification, are discussed. Setup properties and noise features are considered in detail. This review is intended to give newcomers the information needed to design and construct state-of-the-art photoacoustic detectors for specific purposes such as trace gas analysis, spectroscopy, and metrology.