Time-resolved transillumination of turbid media

The suitability and limits of time-resolved transillumination to
determine inner details of biological tissues are investigated by
phantom experiments. The achievable improvement is demonstrated by
using different phantoms (absorbing objects embedded in a turbid
medium). By means of line-scans across a sharp edge the spatial
resolution and its dependence on temporal resolution can be
determined. To demonstrate the physical resolution according to the
Rayleigh-criterion, measurements were performed on blackened bead
pairs. Investigations with partially transparent beads demonstrate
the high sensitivity of time-resolving techniques with respect to
variations in scattering or absorption coefficients.