点击次数：

论文类型：期刊论文

发表时间：2017-10-02

发表刊物：OPTICS EXPRESS

收录刊物：Scopus、SCIE、EI

卷号：25

期号：20

页面范围：A953-A962

ISSN号：1094-4087

摘要：Differential absorption lidar (DIAL) technique employed for remote sensing has been so far based on the sophisticated narrow-band pulsed laser sources, which require intensive maintenance during operation. In this work, a continuous-wave (CW) NO2 DIAL system based on the Scheimpflug principle has been developed by employing a compact high-power CW multimode 450 nm laser diode as the light source. Laser emissions at the online and off-line wavelengths of the NO2 absorption spectrum are implemented by tuning the injection current of the laser diode. Lidar signals are detected by a 45 degrees tilted area CCD image sensor satisfying the Scheimpflug principle. Range-resolved NO2 concentrations on a near-horizontal path are obtained by the NO2 DIAL system in the range of 0.3-3 km and show good agreement with those measured by a conventional air pollution monitoring station. A detection sensitivity of +/- 0.9 ppbv at 95% confidence level in the region of 0.3-1 km is achieved with 15-minute averaging and 700 m range resolution during hours of darkness, which allows accurate concentration measurement of ambient NO2. The low-cost and robust DIAL system demonstrated in this work opens up many possibilities for field NO2 remote sensing applications. (C) 2017 Optical Society of America