Fig. 3: Meta-hologram design based on the partitioned iterative algorithm.
From: Reflective chiral meta-holography: multiplexing holograms for circularly polarized waves

The initial input phase distributions are random for both flow charts. RS and RS−1 represent the Rayleigh–Sommerfeld diffraction formula and the “inverse” Rayleigh–Sommerfeld diffraction formula, respectively. |A| and φ represent the amplitude and phase distributions, respectively