Time-resolved imaging of opaque and transparent spheres embedded in a highly scattering medium

Images are obtained of an object consisting of six small spheres located at different depths within a highly scattering solution of latex microspheres. Three of the spheres are opaque and three are transparent. Imaging involved measuring and discriminating between the flight times of photons diffusely transmitted through the microsphere solution. A series of images are generated by the use of light integrated over periods of time in the range from 10 to 250 ps. As expected, the highest contrast and spatial resolution are achieved by the shortest integration times. However, the transparent spheres are revealed with greater contrast and resolution than the opaque spheres.