Fig. 3: Real-time communication of four 50-bit data streams in parallel.

The comparison between the target data stream and the received output in the four channels, and the measured time-domain signals in each pulse period in four channels. Each of two transmitting units emits a synthesized vortex beam with l1 = +1 and l2 = −1, opening four independent channels marked by Ch1, Ch2, Ch3, and Ch4 respectively.