Figure 5. Results of 8 Gbit s⁻¹ data transmission using mm-wave OAM mode demultiplexer for demultiplexing.

(a) The normalized intensity distributions of four input OAM beams (ℓ=±1 and ℓ=±3) in the OAM mode sorting direction in the detection plane. (b) The received constellations of the 1-Gbaud QPSK signals for OAM channel ℓ=−1 in single Y-pol and dual-pol cases with an SNR=11 dB. (c) Measured BER curves of 1-Gbaud QPSK signals for (i) a single OAM channel (no crosstalk), (ii) two OAM channels on Y-pol (with crosstalk, Y-pol) and (iii) four OAM channels on both X-and Y-pol (with crosstalk, X-pol and Y-pol).