Abstract: Comparative measurements were undertaken in the imaging of oblique structures in scattering media. First, an experimental set-up is described for an optically switched ps-radar. Hereby, laser pulses with duration of 3 ps are used to illuminate the object and an optically switched Kerr-gate which is selecting the light pulses scattered by the object (blood-vessel-phantom). The power of the set-up is demonstrated by the identification of this phantom embedded in several kinds of human tissue. The depth of observation was found in the range of 2 mm to 5 mm. Second, the coherence imaging (CI) is a new technique for non-invasive cross- sectional imaging of biological structure based on low coherence interferometry. In a modified Mach-Zehnder-Interferometer we positioned a phantom (tray with intralipid solution with test structure inside). The transmitted photons were optically modulated. These marked `coherent photons' were detected during an on-dimensional scan through the test structure in the scattering media. !7
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