Ye Weilin, Li Chunguang, Zheng Chuantao, Sanchez Nancy P, Gluszek Aleksander K, Hudzikowski Arkadiusz J, Dong Lei, Griffin Robert J, Tittel Frank K
Opt Express. 2016 Jul 25;24(15):16973-85. doi: 10.1364/OE.24.016973.
A continuous-wave (CW) interband cascade laser (ICL) based mid-infrared sensor system was demonstrated for simultaneous detection of atmospheric methane (CH) and ethane (CH). A 3.337 µm CW ICL with an emitting wavenumber range of 2996.0-3001.5 cm was used to simultaneously target two absorption lines, CH at 2996.88 cm and CH at 2999.06 cm, respectively. The sensor performance was first evaluated for single-gas detection by only targeting the absorption line of one gas species. Allan deviations of 11.2 parts per billion in volume (ppbv) for CH and 1.86 ppbv for CH with an averaging time of 3.4 s were achieved for the detection of these two gases. Dual-gas detection was realized by using a long-term scan signal to target both CH and CH lines. The Allan deviations increased slightly to 17.4 ppbv for CH and 2.4 ppbv for CH with an averaging time of 4.6 s due to laser temperature and power drift caused by long-term wavelength scanning. Measurements for both indoor and outdoor concentration changes of CH and CH were conducted. The reported single ICL based dual-gas sensor system has the advantages of reduced size and cost compared to two separate sensor systems.
展示了一种基于连续波（CW）带间级联激光器（ICL）的中红外传感器系统，用于同时检测大气中的甲烷（CH₄）和乙烷（C₂H₆）。使用发射波数范围为2996.0 - 3001.5 cm⁻¹的3.337 µm连续波ICL，分别同时瞄准两条吸收线，即2996.88 cm⁻¹处的CH₄吸收线和2999.06 cm⁻¹处的C₂H₆吸收线。首先通过仅瞄准一种气体物种的吸收线来评估传感器对单气体检测的性能。在检测这两种气体时，CH₄的体积分数为11.2十亿分之一（ppbv），C₂H₆的体积分数为1.86 ppbv，平均时间为3.4 s时实现了这样的阿伦偏差。通过使用长期扫描信号同时瞄准CH₄和C₂H₆的吸收线来实现双气体检测。由于长期波长扫描导致激光温度和功率漂移，平均时间为4.6 s时，CH₄的阿伦偏差略有增加至17.4 ppbv，C₂H₆的阿伦偏差增加至2.4 ppbv。对室内和室外CH₄和C₂H₆浓度变化进行了测量。所报道的基于单个ICL的双气体传感器系统与两个单独的传感器系统相比，具有尺寸减小和成本降低的优点。
