【作者】 吴志永；

【导师】 胡水明；

【作者基本信息】 中国科学技术大学 ， 物理化学， 2004， 硕士

【摘要】 本文工作是利用激光腔内吸收光谱方法记录气体小分子的泛频高分辨振转光谱及对测量方法进行的改进。第一章主要介绍了腔内吸收光谱技术这一红外波段最常使用的光谱技术，比较深入的讨论了方法的基本原理、灵敏度、分辨率和激光模式等重要内容，实践证明这些对腔内吸收光谱技术的实验工作有直接指导意义。在第二章里，我们介绍了激光腔内吸收光谱的实验装置；讨论了影响光谱测量的分辨率、灵敏度、定量精度等结果的因素及相应的解决方法；利用对C₂H₂分子在12300cm^-1附近微弱吸收谱带的定量测量，对本实验室的傅里叶变换激光腔内吸收光谱装置的性能进行了验证；详述了谱线（绝对）强度的测量和处理；并在原实验装置的基础上，利用信号差分方法减少了光强波动对实验干涉谱图的影响，改善了信噪比。第三章举出了两个应用方面的例子，得到了PH₃分子第五泛频谱带的谱线压力加宽和压力线移系数；通过对¹³CO₂分子8000cm^-1附近弱吸收谱带的测量，验证了使用光谱强度测量获得体系温度的应用方法，探索使用ICLAS方法对火焰温度进行测量。更多还原

【Abstract】 The work included in this thesis is to record high-resolution overtone ro-vibrational spectra of small molecules in gas phase utilizing intra-cavity laser absorption spectroscopy （ICLAS） and the experimental improvement. In Chapter 1,ICLAS, a widely used spectral technique in recent years, is introduced. Emphases are put on the important issues such as principles of ICLAS, sensitivity, resolution and laser mode. From our experience, all these issues are of practical importance in our experimental work. In Chapter 2, the apparatus of ICLAS is introduced, the factors affected the quality of measured spectra are also discussed in detail. Utilizing the equipment in our lab, the performance of the Fourier-transform intra-cavity laser absorption spectroscopy （ FT-ICLAS） was tested by applying to the measurement of the weak bands of acetylene near 12300cm^-1 . The method to do absolute line intensities measurement was also demonstrated. Based on our previous setup, a signal differential module is introduced to reduce the noise rising from the fluctuation of the laser power to improve the quality of the experimental interferogram. In the third chapter, two examples were given to show the applications of FT-ICLAS. The fifth overtone of PH₃ near 12600cm^-1 was recorded, and the self-broadening and line shift parameters were obtained. A weak band of ¹³CO₂ near 8000cm^-1 was recorded to demonstrate the method to achieve sample temperature from the absorption line intensities. The possibility to get flame temperature from ICLAS spectrum is also discussed.更多还原