I’ve never seen “standard” MZMs hit 200G per lane PAM4. I’ve seen PAM6 or 8 get there.
I’ve seen work come out of Peking University that seems to be bleeding edge for SiPh modulators. A non-standard MZ design at 67Ghz where they think they can improve to 80Ghz. They also proposed a slow-light design at >100Ghz but it was mostly theory and initial results indicated there wasn’t enough modulation depth to do PAM4, only OOK.
With the Marvell chatter…they mention 200G SiPh engine and the DSP is PAM4. Is it possible to use PAM6 modulation with a PAM4 DSP?