WMS based dual-range real-time trace sensor for ethane detection in exhaled breath

• Published in: Optics and lasers in engineering 2022-12, Vol.159, p.107222, Article 107222
• Main Authors: Li, Guolin, Wu, Yunhui, Zhang, Zecheng, Zhang, Xuena, Ma, Kun, Jiao, Yue, Li, Jiarui, Liu, Yajing, Song, Yimeng, Zhao, Hao, Zhai, Shenqiang, Li, Qiang
• Format: Article
• Language: English
• Subjects: Dual-range detection; Ethane detection; Interband cascade laser; Tunable diode laser absorption spectroscopy; Wavelength modulation spectroscopy
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2022.107222

•A dual-range real-time ethane trace sensor was developed to meet demands for high sensitivity and dual-range ethane detection in exhaled breath in different subject populations for early screening and diagnosis of lung cancer. Based on TDLAS and WMS techniques, a 3.34 µm ICL and a long-range MPGC were adopted in the sensor, which achieve dual-range detection of ethane in exhaled breath with a resolution of 5 ppb.•The LoD of the dual-range real-time trace sensor for ethane detection in exhaled breath is ∼687 ppt with a 2 s integration time and is a minimum value of ∼231 ppt with a 44 s optimum integration time.•The sensor provides high sensitivity, linearity and accuracy for the detection of ethane in exhaled breath at ppm-level and ppb-level. The sensor provides a practical technical supplement for early screening and diagnosis of lung cancer, and has important application value in the field of exhaled breath detection. A highly sensitive mid-infrared dual-range real-time trace sensor was developed for ethane detection in exhaled breath, in which a continuous-wave (CW) mode interband cascade laser (ICL) emitting at 3348.2 nm and a multi-pass gas cell (MPGC) with an effective optical absorption length of 76.3 m were adopted in the trace sensor. The ethane concentration in the exhaled breath was measured by scanning the ethane absorption lines at 2986.7 cm−1 and 2988.2 cm−1 using wavelength modulation spectroscopy (WMS) techniques of tunable diode laser absorption spectroscopy (TDLAS), which allows for highly sensitive detection in two ethane concentration ranges. The Allan deviation indicated the limit of detection (LoD) of the sensor system can be averaged up to ∼269 ppt over the entire integration time.