An all-optical photoacoustic spectroscopy based on lock-in white-light interferometry is proposed for trace gas detection. The cavity length of the fiber-optic Fabry-Perot cantilever microphone is demodulated by a high-speed white-light interferometer, whose spectral sampling is synchronously triggered by a phased locked signal. To improve the signal-to-noise ratio, the demodulated digital photoacoustic signal is further processed by a specially designed virtual lock-in amplifier. The designed photoacoustic spectrometer has been tested for trace acetylene (CH) detection in the near-infrared region. The normalized noise equivalent absorption coefficient for CH is achieved to be 1.1×10 cm W Hz.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/OL.43.005038 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Compact and full-range carbon dioxide sensor using photoacoustic and resonance dependent modes.
Photoacoustics
February 2025
Dipartimento di Scienze di Base ed Applicate per l'Ingegneria, Sapienza Università di Roma, Rome 00161, Italy.
A compact and robust optical excitation photoacoustic sensor with a self-integrated laser module excitation and an optimized differential resonator was developed to achieve high sensitivity and full linear range detection of carbon dioxide (CO) based on dual modes of wavelength modulated photoacoustic spectroscopy (WMPAS) and resonant frequency tracking (RFT). The integrated laser module equipped with three lasers (a quantum cascade laser (QCL), a distributed feedback laser (DFB) and a He-Ne laser) working in a time-division multiplexing mode was used as an integrated set of spectroscopic sources for detection of the designated concentration levels of CO. With the absorption photoacoustic mode, the WMPAS detection with the QCL and DFB sources was capable of CO detection at concentrations below 20 %, yielding a noise equivalent concentration (NEC) as low as 240 ppt and a normalized noise equivalent absorption coefficient (NNEA) of 4.
View Article and Find Full Text PDFA Review on Photoacoustic Spectroscopy Techniques for Gas Sensing.
Sensors (Basel)
October 2024
Electrical and Computer Engineering Department, Missouri University of Science and Technology, Rolla, MO 65401, USA.
The rapid growth of industry and the global drive for modernization have led to an increase in gas emissions, which present significant environmental and health risks. As a result, there is a growing need for precise and sensitive gas-monitoring technologies. This review delves into the progress made regarding photoacoustic gas sensors, with a specific focus on the vital components of acoustic cells and acoustic detectors.
View Article and Find Full Text PDFA fast all-optical 3D photoacoustic scanner for clinical vascular imaging.
Nat Biomed Eng
September 2024
Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
Article Synopsis
- The study discusses advancements in photoacoustic tomography (PAT) for visualizing microvascular structures, essential for assessing conditions like diabetes and inflammatory skin diseases.
- By improving the scanner's speed from minutes to mere seconds or milliseconds, the authors enable better visualization with less motion-related interference and detailed 3D imaging.
- These enhancements allow for the exploration of microvascular changes in various medical conditions, suggesting potential applications in fields such as cardiovascular medicine, oncology, dermatology, and rheumatology.
All-Optical Photoacoustic Spectroscopy-Based Dual-Component Greenhouse Gas Analyzer.
Anal Chem
September 2024
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China.
To achieve high sensitivity detection of dual-component greenhouse gases carbon dioxide and methane simultaneously, a multimechanism synergistic enhanced all-optical photoacoustic spectroscopy gas analyzer is presented. The acoustic resonance of the photoacoustic cell and the mechanical resonance of a fiber-optic cantilever acoustic sensor are used to enhance the photoacoustic signals of the dual-component gas. The optimized multipass beam reflection structure enhances the effective excitation power of the dual-component gas.
View Article and Find Full Text PDFArticle Synopsis
- - Ultrasound coupling is a major challenge in using traditional photoacoustic microscopy (PAM) for clinical examination of chronic wounds.
- - Photoacoustic remote sensing (PARS) is a promising solution that utilizes all-optical measurements and has shown potential in functional imaging of tissue but needs further exploration in hemodynamic quantification.
- - The study introduces an all-optical thermal-tagging flowmetry method for PARS Microscopy, demonstrating its effectiveness with high accuracy in measuring blood flow rates from 0 to 12 mm/s without using dyes.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!