A method is presented for high-range resolution measurement of the backscatter from a scattering medium located in one arm of an interferometer. The technique is interferometric in nature and relies on the availability of a cw laser with a significant linewidth. The measurement is based on observing coherent interference (equivalent to white-light fringes) between the return from the two arms of the interferometer for the portion of the backscatter that makes the path lengths equal. Experimental results are presented for backscatter from a turbid medium and from a stack of glass plates.
A. P. Ivanov, A. P. Chaikovskii, and A. A. Kumeisha, "New method for high-range resolution measurements of light scattering in optically dense inhomogeneous media," Opt. Lett. 1, 226-228 (1977)