van Veen Eric H, Roekaerts Dirk
Department of Multi-Scale Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
Appl Opt. 2005 Nov 10;44(32):6995-7004. doi: 10.1364/ao.44.006995.
An optimal system for temperature measurements by coherent anti-Stokes Raman spectroscopy (CARS) in turbulent flames and flows is presented. In addition to a single-mode pump laser and a modeless dye laser, an echelle spectrometer with a cross disperser is used. This system permits simultaneous measurement of the N2 CARS spectrum and the broadband dye laser profile. A procedure is developed to use software to transform this profile into the excitation profile by which the spectrum is referenced. Simultaneous shot-to-shot referencing is compared to sequential averaged referencing for data obtained in flat flames and in room air. At flame temperatures, the resultant 1.5% imprecision is limited by flame fluctuations, indicating that the system may have a single-shot imprecision below 1%. At room temperature, the 3.8% single-shot imprecision is of the same order as the best values reported for dual-broadband pure-rotational CARS. Using the unique shot-to-shot excitation profiles, simultaneous referencing eliminates systematic errors. At 2000 and 300 K, the 95% confidence intervals are estimated to be +/- 20 and +/- 10 K, respectively.
本文介绍了一种用于在湍流火焰和流场中通过相干反斯托克斯拉曼光谱（CARS）进行温度测量的优化系统。除了单模泵浦激光器和无模染料激光器外，还使用了带有交叉色散器的阶梯光栅光谱仪。该系统允许同时测量N2的CARS光谱和宽带染料激光轮廓。开发了一种程序，使用软件将该轮廓转换为用于参考光谱的激发轮廓。将同时逐次参考与在平面火焰和室内空气中获得的数据的顺序平均参考进行了比较。在火焰温度下，由此产生的1.5%的不精确性受火焰波动限制，这表明该系统单次测量的不精确性可能低于1%。在室温下，3.8%的单次测量不精确性与双宽带纯转动CARS报告的最佳值处于同一数量级。使用独特的逐次激发轮廓，同时参考消除了系统误差。在2000K和300K时，95%置信区间估计分别为+/-20K和+/-10K。
