Single-shot measurement of the extinction coefficient of turbid media based on two-dimensional intensity spatial distribution and least-mean-square algorithm.

We propose a method to measure the extinction coefficient of turbid media by using the two-dimensional intensity spatial distribution and least-mean-square algorithm. Furthermore, we have conducted a comparative analysis of extinction coefficients determined by both the least-mean-square filtering method and the traditional collimation transmission method. The experimental results reveal that the extinction coefficients measured by using both the methods are identical for weakly turbid media, while the extinction coefficients measured by using the least-mean-square filtering method are ∼20% higher than those determined by the collimation transmission method for highly turbid media. This discrepancy can be attributed to the least-mean-square filtering method providing a significant reduction in the near-axis diffused photons compared with the conventional collimation transmission approach, which allows us to obtain a more accurate extinction coefficient of a turbid medium, especially those turbid media with a high degree of turbidity.