Shape Optimization of an Open Photoacoustic Resonator

Lars Duggen,Said El-Busaidy,Bernd Baumann,Marcus Wolff

doi:10.3390/app11062571

Lars Duggen, Said El-Busaidy + Show 2 more

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https://doi.org/10.3390/app11062571

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Abstract

Photoacoustic (PA) measurements with open resonators usually provide poor detection sensitivity due to signal leakage at the resonator opening. We have recently demonstrated three different approaches for modelling the photoacoustic signal of open resonators. In this work, one of the approaches is applied for the optimization of the geometry of the T-shaped resonator for improved signal strength and thus sensitivity. The results from the numerical optimization show an increase in the photoacoustic signal by a factor of approximately 7.23. They are confirmed using numerical methods other than the one applied for the optimization and by experimental measurement. The measurement shows an increase in the photoacoustic signal by a factor of approximately 2.34.

Highlights

Photoacoustic spectroscopy (PAS) is a technique based on the generation of an acoustic signal after the absorption of light by molecules [1]
We describe a procedure for optimizing the open T-shaped resonator used in PA blood glucose measurements for a maximum signal in the ultrasound range
We have previously described three different approaches for simulating the PA signal in open resonators: the viscothermal model with perfectly matched layers (VT-PML), the viscothermal model with boundary element method (VT-BEM) and the amplitude expansion model with perfectly matched layers (AME-PML) [21]

Summary

Introduction

Photoacoustic spectroscopy (PAS) is a technique based on the generation of an acoustic signal after the absorption of light by molecules [1]. It has been widely applied in numerous fields ranging from evaluation of materials [2,3], agriculture [4,5], medical/biological applications [6,7,8] and environmental analysis [9,10,11]. In a conventional experimental setup the sample is located inside a sealed resonator. In specific applications a closed resonator is not suitable, and an open resonator configuration is required

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