Phase-dispersion optical tomography

We report on phase-dispersion optical tomography, a new imaging technique b ased on phase measurements using low-coherence interferometry. The techniqu e simultaneously probes the target with fundamental and second-harmonic Lig ht and interferometrically measures the relative phase shift of the backsca ttered Light fields. This phase change can arise either from reflection at an interface within a sample or from bulk refraction. We show that this hig hly sensitive (similar to5 degrees) phase technique can complement optical coherence tomography, which measures electric field amplitude, by revealing otherwise undetectable dispersive variations in the sample. (C) 2001 Optic al Society of America.