中文摘要：

利用单个新型中红外量子级联激光器作为激光光源,结合长程光学吸收池技术开展了大气多组分同时测量方法的研究.通过结合基于自适应性Savitzky-Golay滤波的数据处理算法,有效地提高了系统检测灵敏度和光谱分辨率.研究结果表明,在1 s的时间分辨率和1 atm压力条件下,采用二次微分探测技术可实现CO,N2O和H2O测量精度分别为8.20 ppb,7.90 ppb和64.00 ppm（1 ppb=10-9,1 ppm=10-6）;通过提高信号平均时间,在最佳的积分时间（85 s）时,系统可实现的最小检测限分别为1.25 ppb（CO）,1.15 ppb（N2O）和35.77 ppm（H2O）.整个系统具有结构紧凑,成本相对较低,通过选择其他波段的量子级联激光器的激光光源,即可实现对其他分子的实时分析.本系统可广泛应用于大气化学等领域的应用研究.

英文摘要：

Quantum cascade lasers （QCLs） are relatively new sources of mid-infrared radiation （between 2.5 μm and 25 μm）, and are very well suited to the application of in-field trace gas sensing, mainly due to their superiority of being robust, compact, wavelength-versatile, narrow line width and low power consumption. All these advantages make the laser absorption spectroscopy based on QCL light sources become one of the most popular technologies for the quantitative chemical detection in a variety of fields including atmospheric enviromnental monitoring, chemical analysis, industrial process control, medical diagnostics, security or bio-medical studies, etc. In the present work, a highly sensitive mid-infrared gas sensor employing a single continuous-wave distributed feedback QCL and an astigmatic multi-path optical absorption cell is demonstrated for the simultaneous measurement of atmospheric carbon monoxide （CO）, nitrous oxide （N~O） and water vapor （H20）. By combining with an adaptive Savitzky-Golay （S-G） filter signal processing algorithm, the detection sensitivity and spectral resolution of the QCL sensor system are significantly improved. Compared with the traditional wavelet transform based signal de-noising technique, the developed adaptive S-G smoothing filter shows obvious advantages in terms of computational efficiency and selection of the optimal filter parameters, namely only two filter parameters （the width of the smoothing window and the degree of the smoothing polynomial） need to be considered. Currently, the QCL sensor system is estimated for the long term measurement of ambient air in laboratory environment. The results show that measurement preeisions of 8.20 ppb （1 ppb = 10-9） for CO, 7.90 ppb for N20, and 64.00 ppm （1 ppm = 10-6） for H20 at 1 s time resolution and 1 atmospheric pressure （atm） are obtained by using the quadratic differential detection scheme, which can be further improved to 1.25 ppb （for CO）, 1.15 ppb （for N2O） and 35.77 ppm （for H