Comparison of phase retrieval methods for optical diffraction tomography

Abstract

We compare three different phase retrieval methods for applications in optical diffraction tomography (ODT). The first method is based on Gabor holography and is limited by the 'twin-image' problem. The second is an iterative approach for which the uniqueness of the retrieved phase is questionable. In the third method the phase is measured by phase shifting interferometry (PSI), but this technique is more demanding experimentally. Using realistic computer simulations, which include noise and lens aberrations, we show that the PSI method determines the phase accurately. The iterative method gives equally accurate results in most cases. But in some cases this method produces a false phase. This problem is demonstrated using both simulated and experimental intensity data. The images reconstructed from the false phases are found to be severely distorted. We also show that the uniqueness problem can be avoided by increasing the distance between the scattering object and the measurement line.