Fig. 2: Modified iterative Fourier transform algorithm.
From: Broadband decoupling of intensity and polarization with vectorial Fourier metasurfaces
With respect to intensity-only iterative Fourier transform algorithm, the current version considers several input information to realize diffraction patterns with arbitrary intensity, azimuth, and ellipticity angles of the polarization. The algorithm converges to a vectorial profile optimizing the amplitude of both LCP (\({a}_{+}^{f}\)) and RCP (\({a}_{-}^{f}\)), and the phase difference between the two CP beams (\({\alpha }^{f}\)). The notation \(\sigma\) represents the handiness of the CP beam, where \(+\) or \(+1\) represents LCP and \(-\) or \(-1\) represents RCP. A random phase of \({\varphi }_{\mathrm{rd}}\) is used for the starting phase. The number of iterations is N = 100. The final holographic phase of the metasurface is \({\varphi }_{\sigma }^{m}\). The superscript m indicates the metasurface plane and f is the image plane in the far field (see more details in Supplementary Note 1).
