抄録
Two-beam interferometers and differential interferometers are used for optical computed tomo-graphy (CT) to reconstruct refractive-index distributions. In this paper, the two types of interfer-ometers have been compared with respect to the effects of random noise in the projection data and the spatial resolutions of the reconstructed index distributions. The reconstructions are assumed to be performed using the filtered back projection method. The noise effects were evaluated using the random variable theory and numerical simulations. The result shows that when the amount of shear for the transmitted light in the differential interferometer is larger than the sampling distance of the projected light distribution, the noise level in the index distribution is smaller than that of the two-beam type. However, the large amount of shear restricts the spatial resolution of the distribution.
