Theoretical and experimental study of optical diffractometry based on Fresnel diffraction from a transmission phase step

Abstract

We present experiments to study the optical diffractometry of Fresnel diffraction from transmission phase steps under illuminating sources with distinct spatial profiles. The experimental results are extended analytically with the Fresnel Gaussian shape invariant introduced in previous publications to calculate the propagation of a coherent illuminating source through optical setups. We use a narrow coherent illuminating source to permit extending the applicability of the method for clinical purposes and perform calculations with illuminating sources with different spatial profiles, including a non-diffracting Airy beam, to allow for the establishment of general sensitivity formulae within the paraxial region.