Reflection of a Diffuser in a Liquid Interface

We present a novel method, based on the Saunderson corrections, to predict the reflectance between a liquid interface and a dielectric diffuser. In this method, the diffuse properties of the dielectric are characterized using a single parameter, the multiple-scattering albedo, which is the same irrespective of being in contact with air or liquid. We tested this method using an apparatus based on a total integrating sphere capable of measuring reflectance in both liquid and gas interfaces across various wavelengths of light. We observed that the difference in the value of the multiple-scattering albedo between the sphere full of liquid and empty was less than 0.9$\times 10^{-3}$, with the average difference normalized to the respective uncertainty of only 0.7. These results confirm the reliability of our method and its potential for use in a wide range of practical applications.