Observation of optical memory effect due to interference of multiply scattered light by using a focused beam

We studied a wavelength discriminating optical memory effect, which is due to interference of multiply scattered light, using a focused incident light beam in order to estimate its wavelength and spatial resolutions. The spatial resolution is dependent solely on the beam radius on the incident plane, although light diffuses and spreads in the scattering medium. The wavelength resolution is only slightly reduced even if the incident light is tightly focused.