Abstract: A new method of measuring the two-dimensional tomography of gas parameters in non-uniform combustion filed is proposed based on the wavelength modulation spectroscopy. The two-dimensional tomography of gas parameters can be measured according to inversion algorithms using the measured integrated absorbance of laser through non-uniform field and reconstruction algorithms. A method of measuring the integrated absorbance is studied according to fitting the harmonic signals based on wavelength modulation spectroscopy. The two H2O spectral lines(7185.60cm-1 and 7454.45cm-1)are chosen. By establishing discrete model and designing appropriate light distribution，the two-dimensional tomography of temperature and H2O concentration in non-uniform field can be realized using the wavelength modulation spectroscopy method and algebra iterative algorithm. The simulation results show that the measurement method based on wavelength modulation spectroscopy has high measurement accuracy. Comparing to the predicted value，the reconstruction error of temperature and H2O concentration is less than 1.69% and 3.05%，respectively.

Key words: Wavelength modulation spectroscopy；Combustion field；Two-dimensional tomography；Integrated absorbance

摘要： 基于波长调制光谱方法，研究了一种实现非均匀燃烧场气体参数二维分布测量的新方法。气体参数的二维分布是通过测量激光穿过非均匀流场区域的积分吸光度并结合重建算法进行反演实现。研究了基于波长调制光谱，通过拟合谐波信号实现积分吸光度测量的方法。利用所选的7185.60cm-1和7454.45cm-1两条H2O谱线，通过建立离散模型和设计光线布局，基于波长调制光谱方法和代数迭代重建算法实现了非均匀流场区域内温度场和H2O组分浓度场的二维分布测量。重建结果表明:基于波长调制光谱的二维重建方法具有较高的重建精度，与预测值相比，温度和H2O组分浓度的重建误差分别小于1.69%和3.05%。

关键词: 波长调制光谱；燃烧场；二维分布测量；积分吸光度