Fast-Switchable OAM-Based High Capacity Density Optical Router

We propose and demonstrate an optical router by selecting data encoded in massive orthogonal orbital angular momentum (OAM) states carried by collinear optical vortex (OV) beams. By switching the OV grating on a digital micromirror device, we achieve information exchange and multicasting in 49 OAM channels with 1.37 Tbit/s aggregated data capacity. The time-domain characterization of the OAM router shows a fast-switching time of 6.9  μs. Both the analytical derivations and experimental demonstrations show that the router has signal-to-noise ratios (SNRs) better than 10.1 dB for all tens of OAM channels. The OAM-based optical interconnect technique is a promising solution for networking multiple users with ultrahigh data capacity density in datacenters.