We demonstrate the use of hybrid rotational femtosecond/picosecond (fs/ps) coherent anti-Stokes Raman spectroscopy (HR-CARS) as a technique for temperature measurements in nitrogen gas at high pressures and temperatures. A broadband pulse shaper-adjusted 42 fs pulse interacts with a narrow-bandwidth, frequency-upconverted 5.5 ps pulse in a cell containing $ {{\rm{N}}_{{2}}} $ at pressures of 1–70 atm and temperatures of 300–1000 K. A computational code is used to model spectra and fit experimental results to obtain best-fit temperatures. We demonstrate good qualitative fits as well as good accuracy and precision between thermocouple measured and best-fit temperatures over the explored pressure and temperature regimes. The overall average percentage temperature difference between thermocouple measurements and best-fit temperatures is $ - {{0}}.{{3}}\% $ with a standard deviation of 7.1%, showing the suitability of HR-CARS for characterizing high-pressure and -temperature environments.

中文翻译：

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在高压和高温下优化混合旋转飞秒/皮秒相干反斯托克斯拉曼光谱

我们展示了混合旋转飞秒/皮秒（fs / ps）相干反斯托克斯拉曼光谱（HR-CARS）作为高压和高温下氮气温度测量的技术。在包含$ {{\ rm {N}} _ {{2}}} $的单元中，宽带脉冲整形器调整的42 fs脉冲与窄带宽，频率上变频的5.5 ps脉冲相互作用。在1–70 atm的压力和300–1000 K的温度下使用。计算代码用于对光谱建模并拟合实验结果以获得最佳拟合温度。我们证明了在探索的压力和温度范围内，热电偶测得的温度和最佳拟合温度之间具有良好的定性拟合以及良好的精度和精密度。热电偶测量值与最佳温度之间的总体平均温差百分比为$-{{{0}}。{{3}} \％$，标准偏差为7.1％，这表明HR-CARS适合表征高功率压力和温度环境。