Optical tomography based on phase-shifting schlieren deflectometry

We present a new optical tomography technique based on phase-shifting schlieren deflectometry. The principle is that of computerized tomography. The three-dimensional profile is reconstructed from the deflection angles of rays passing through the tested object. We have investigated optical phantoms chosen in view of the characterization of dendritic growth in a solidification process. Promising results have been obtained with a homogeneous sphere and a bundle of 200 mu m fibers. The deviation angles exceed two degrees with a variation of the refractive index Delta n = 0.025.Anglai