Coherent noise reduction in optical diffraction tomography

Abstract

Optical Diffraction Tomography (ODT) is the method for characterization of 3D distribution of refractive index in micro optical elements. The 3D distribution is obtained from several measurements taken for different object angular orientation taken by means of laser interferometry. Unfortunately the interferometry as a coherent technique suffers from undesirable coherent noise in measurements results. Additionally the rotation of a measured object increases the noise influence on the quality of refractiveindex reconstruction due to its amplification in the object area. In this paper we propose the coherent noise suppression technique. The technique involves modification of ODT setup configuration by introducing off center object rotation and applying a modified numerical algorithm of tomographic reconstruction. The algorithm modification involves introduction of numerical imaging and detection of element position from its diffraction spectrum. The received results of noise reduction are shown through numerical simulations and experiments involving optical single mode fiber measurements.