Figure 1
From: A two-way 224-Gbit/s PAM4-based fibre-FSO converged system
(a) The optical spectra of VCSEL1 in free-running and injection-locked states with 56 Gbit/s PAM4 data signal. (b) The modulation responses of VCSELs in free-running and injection-locked scenarios with 56 Gbit/s PAM4 data signal.
