Fig. 7: Proof-of-concept of MIMO experiment.

a Photograph of the 2-by-2 MIMO setup in the lab (left). Two laser diodes (LDs) are used to transmit the signals. One large aspheric lens is used at the receiver to focus the light beams on two separate OPV cells (right). b Estimated and measured SNR values for two channels of the 2-by-2 MIMO experiment.