Ma, YufeiTong, YaoHe, YingYu, XinTittel, Frank K.2018-07-112018-07-112018Ma, Yufei, Tong, Yao, He, Ying, et al.. "High-Power DFB Diode Laser-Based CO-QEPAS Sensor: Optimization and Performance." <i>Sensors,</i> 18, no. 1 (2018) MDPI: https://doi.org/10.3390/s18010122.https://hdl.handle.net/1911/102397A highly sensitive carbon monoxide (CO) trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was demonstrated. A high-power distributed feedback (DFB), continuous wave (CW) 2.33 μm diode laser with an 8.8 mW output power was used as the QEPAS excitation source. By optimizing the modulation depth and adding an optimum micro-resonator, compared to a bare quartz tuning fork (QTF), a 10-fold enhancement of the CO-QEPAS signal amplitude was achieved. When water vapor acting as a vibrational transfer catalyst was added to the target gas, the signal was further increased by a factor of ~7. A minimum detection limit (MDL) of 11.2 ppm and a calculated normalized noise equivalent absorption (NNEA) coefficient of 1.8 × 10−5 cm−1W/√Hz were obtained for the reported CO-QEPAS sensor.engThis is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedJournal articleQEPAScarbon monoxidehigh power diode lasergas sensorhttps://doi.org/10.3390/s18010122