(color online) (a): Schematic diagram of the proposed experiment, collimated light beam impinges on DMD which is loaded with the hologram pattern to produce the Fourier transformed states of the initial states, .The beam reflects in +12° direction is blocked. A 4f system selects the 1st diffraction order. The produced statespass through the black box which performs the permutation operations. A CCD camera records the patterns. (b): Details of the OAM sorter. (c)–(j): Details of the eight possible operations.