Numerical study of grating-assisted optical diffraction tomography

摘要

We study the resolution of an optical diffraction tomography system in which the objects are either in an homogeneous background or deposited onto a glass prism, a prism surmounted by a thin metallic film or a prism surmounted by a metallic film covered by a periodically nanostructured dielectric layer. For all these configurations, we present an inversion procedure that yields the map of the relative permittivity of the objects from their diffracted far field. When multiple scattering can be neglected, we show that the homogeneous, prism, and metallic film configurations yield a resolution about lambda/4 while the grating substrate yields a resolution better than lambda/10. When Born approximation fails, we point out that it is possible to neglect the coupling between the object and the substrate and account solely for the multiple scattering within the objects to obtain a satisfactory reconstruction. Last, we present the robustness of our inversion procedure to noise.