Using terahertz pulses to study light scattering

We describe a new experimental technique for studying the propagation of light in scattering media. We use terahertz time-domain spectroscopy to generate and detect sub-picosecond pulses of far infrared radiation, and employ these pulses in spectroscopic studies of synthetic random media. This technique offers a number of unique advantages in comparison with other experimental methods, including the coherent detection of the electromagnetic field, the broad bandwidth, and the ease of sample preparation. As a first demonstration, we study the ballistic transport through a dense collection of spheres. These results are compared with the predictions of the quasi-crystalline approximation. r 2003 Elsevier B.V. All rights reserved.