A Sensitive Carbon Dioxide Sensor Based on Photoacoustic Spectroscopy with a Fixed Wavelength Quantum Cascade Laser

Sensors

FrankK. Tittel¹  Yao Wang²  Yanchen Qu²  Ying He²  Shunda Qiao²  Yinqiu Hu²  Yufei Ma²  Xin Yu²  Zhonghua Zhang² 

[1] Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA;National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150001, China;

关键词: photoacoustic spectroscopy;    carbon dioxide detection;    quantum cascade laser;   

DOI  :  10.3390/s19194187

来源: DOAJ

【 摘 要 】

A photoacoustic spectroscopy (PAS) based carbon dioxide (CO₂) sensor with a fixed wavelength quantum cascade laser (FW-QCL) was demonstrated. The emission wavelength of the FW-QCL at 4.42 μm in the mid-infrared spectral region matched a fundamental CO₂ absorption line. Amplitude modulation of the laser intensity was used to match the resonant photoacoustic (PA) cell. The noise from the background was reduced with the correlation demodulation technique. The experimental results showed that the sensor had excellent signal stability and a concentration linear response. When the integration time was 1 s, a 1σ minimum detection limit (MDL) of 2.84 parts per million (ppm) for CO₂ detection was achieved. The long-term stability of the sensor was evaluated by means of an Allan deviation analysis. With an integration time of ~100 s, the MDL was improved to 1 ppm. This sensor was also used to measure the CO₂ concentration from some common emission sources, such as cigarette smoking, automobile exhaust, and the combustion of some carbon-containing materials, which confirmed the stability and robustness of the reported FW-QCL based CO₂-PAS sensor system.

【 授权许可】

Unknown