Figure 3
From: A two-way 224-Gbit/s PAM4-based fibre-FSO converged system
(a) The BER performances of 256 Gbit/s PAM4-based fibre-FSO converged system (uplink transmission) in sunny weather under the scenarios of BTB (y-polarisation), over 500-m free-space transmission (y-polarisation), over 500-m free-space and 25-km SMF transmissions (x- and y-polarisations), over 600-m free-space and 25-km SMF transmissions (y-polarisation), over 500-m free-space and 30-km SMF transmissions (y-polarisation), as well as over 500-m free-space and 35-km SMF transmissions (y-polarisation). The eye diagrams of 56 Gbit/s PAM4 signal under the conditions (b) over 500-m free-space transmission (y-polarisation), (c) over 500-m free-space and 25-km SMF transmissions (y-polarisation), and (d) over 600-m free-space and 25-km SMF transmissions (y-polarisation).
