Towards the optimization of photoacoustic sensors

Abstract

The detection sensitivity of photoacoustic sensors strongly depends on the design of the acoustical cell. It can be considerably improved by taking advantage of cell resonances, i.e., the acoustical eigenmodes of the measuring chamber. In order to optimize a photoacoustic system, it is key to understand precisely the influence of optical excitation, sound wave generation, cell shape and microphone detection on the signal strength in the sample cell. In this paper, first steps towards the optimization of photoacoustic cells are presented. The evaluation of the objective function, the signal strength, is based on a finite element analysis of the pressure field. As a start, independent optimization of some key parameters are investigated.