The 400G EML fills a gap for 1.6T pluggable and the only reason big players are demanding that Mitsu provide it in an integrated solution is because the stand alone device needs to be packaged in a platform for mass production to fill the pain point needs. Those needs extend to distances that cannot be met by copper or even the short reach VCSEL. There is demand right now by industry for a 1.6T solution. It's not going to be the ultimate solution going into the future. There will be new integrated devices that will fill those needs with greater efficiency and I believe that POET is on it.  Suresh is a genius at finding solutions to problems that are worth solving.

Good to hear that Lumentum has been successful at producing a 400G EML. I expect they are knocking on POETs door to provide integration since we do know they have a relationship and will be looking for a packaging solution.