Figure 3

Amplitude images of OAM modes. Three different time sequence schemes are presented, including the time sequence with SPST switch in ref.10, the proposed time sequence with SPST switch and the proposed time sequence with SPDT switch. The simulated data is normalized to the maximum value. Each mode is labelled by its topological charge l. A change in color from blue to red corresponds to a change in amplitude from −70 dB to 0 dB.