Abstract A hybrid method based on combining the light-field imaging and laser extinction techniques is proposed to reconstruct the 3D temperature and absorption coefficient fields in the pure absorbing flame. The inhomogeneous absorption coefficient distribution can be recovered based on the exit laser signals according to Beer-Lambert law firstly. According to the attained absorption coefficient distribution, the temperature field can be retrieved accurately with high efficiency by utilizing the light-field imaging technique. Besides, the influence of two types of measured signal noises, i.e. the laser signal noise and the light-field image signal noise, on the reconstructed quality have been investigated thoroughly. The Landweber method is adopted to solve the inverse analysis. All the results showed that the 3D temperature and absorption coefficient distribution can be reconstructed accurately and efficiently with different measurement noises, which proves the feasibility of the proposed method for the non-contact measurement of 3D temperature and absorption coefficient distributions of absorbing flame.

中文翻译：

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混合光场成像和激光消光技术重建3D火焰温度和吸收系数场

摘要 提出了一种基于光场成像和激光消光技术相结合的混合方法来重建纯吸收火焰中的3D温度场和吸收系数场。首先根据Beer-Lambert定律，基于出射激光信号可以恢复非均匀吸收系数分布。根据获得的吸收系数分布，利用光场成像技术可以准确、高效地反演温度场。此外，还深入研究了激光信号噪声和光场图像信号噪声这两种被测信号噪声对重建质量的影响。逆分析采用Landweber方法求解。