Near-Field Experimental Verification of Separation of OAM Channels

The experimental proof that near-field radio communication channels based on orbital angular momentum (OAM) are naturally isolated is presented. In near-field zone, we show that two antennas, built for producing a beam with the same value of OAM, have a good throughput. On the other hand, antennas of different types, i.e., built for generating beams with different OAM values, including a standard $\ell = 0$ antenna, exhibit a good modal isolation .