Super-resolution in diffractive imaging from hemispherical elastic light scattering data

Angle-resolved hemispherical elastic light scattering techniques have been used to reconstruct the surface profile of two-dimensional photonic crystals with submicron resolution and metrological precision. Iterative algorithms permit subsequent calculation of a surface autocorrelation function with additional numerical approximation of the power spectrum and then yield final reconstruction of the surface shape. The proposed method enables filtering out unwanted scattering background, precluding the convergence of phase-retrieval algorithms. The estimation of higher harmonics in the power spectrum provides the reconstruction of a realistic surface achieving subwavelength resolution.