A model of speckle contrast in optical coherence tomography for characterizing the scattering coefficient of homogenous tissues.

We present a theoretical model for analyzing the speckle contrast of optical coherence tomography (OCT). This model is based on the addition of noise and an OCT signal in the logarithmic scale. The theoretical model reveals that, for the superficial layer of homogenous tissue, the contrast ratio is a linear function of the location of the coherence gate in the sample and the slope of this linear dependence is proportional to the scattering coefficient. The theoretical model is consistent with the experimental results, suggesting that the slope can be useful to characterize the scattering coefficient of the homogenous samples.