Photoacoustic and light-induced thermoelastic spectroscopy for gas sensing: from theoretical modeling to applications
摘要截稿:
全文截稿: 2024-12-31
影响因子: 9.656
期刊难度:
CCF分类: 无
中科院JCR分区:
• 大类 : 工程技术 - 2区
• 小类 : 工程:生物医学 - 2区
• 小类 : 仪器仪表 - 1区
• 小类 : 核医学 - 2区
Overview
Photoacoustic spectroscopy is one of the most powerful techniques for gas sensing. Based on the photoacoustic (PAS) effect, the detection of acoustic waves generated from gases exposed to light allows a precise measurement of gas concentration. Several different detection methods to pick up photoacoustic waves have been implemented over the years, among them: quartz tuning forks (QTFs), membrane microphone in resonant cell, cantilever and bridge acoustic sensors for miniaturized detectors. Light Induced Thermoelastic Spectroscopy (LITES) is an emerging non-contact optoacoustic technique for gas sensing. LITES exploits QTFs as the optical detectors in a Laser Absorption Spectroscopy configuration. The excitation laser beam passes through a gas cell and is absorbed by the target gas molecules while modulated at the QTF resonance frequency or one of its subharmonics. Then, the optical beam coming out from the gas cell is focused on one of the QTF prongs surfaces, generating a modulated localized heating and consequently a quartz crystal thermoelastic expansion. Thus, modulated optical absorption generates acoustic waves and deformations inside the quartz crystal which in turn produces a piezoelectric charge distribution on the quartz fork. The generated piezoelectric charges distribution can be collected using the metal contact patterns deposited on the QTF surface. LITES with respect to Quartz-enhanced photoacoustics spectroscopy (QEPAS) has the advantage that the QTF is positioned out of the gas cell, thereby allowing non-contact measurements.
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PAS and LITES can cover a broad range of applications including that covers a broad range of applications including atmospheric monitoring, petrochemistry, industrial process control and security as well as biomedical applications. From visible light to terahertz spectral range, PAS and LITES can be employed with all kinds of laser sources. Specific sensor designs have been proposed to enhance performance, such as for example the use of multipass cell to enhance the light-gas interaction path or cavity-enhanced approach to increase the exciting optical power.
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This Special Issue plans to review a collection of high-quality research articles focused on new developments in PAS and LITES sensors for applications as well as novel technologies, with also a focus on study of fundamentals and methodology of photoacoustic and LITES detection. Both reviews and original research articles will be published. Reviews should provide an up-to-date well-balanced overview of the current state-of-the-art in a particular field and include main results from other groups.
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Researchers are welcome to contribute in all areas of photoacoustic spectroscopy and LITES including, but not limited to:
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Guest editors:
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Executive Guest Editor
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Co-Guest Editors