On biospeckle size analysis technique in particle concentration and size assessment

When coherent light crosses a medium having biological cells as scattering centers in suspension a speckled image is obtained in the far field, called biospeckle. Speckle size can bring information on the scattering media. The scattering media were diluted milk and urine. Digital image files were recorded. For each image the average speckle size was calculated using the intensity correlation function. We found that the aver-age speckle size decreases linearly as the scattering center concentration increases, in the small concentration range and increases back at bigger concentrations. Possible biomedical applications are discussed.