Kryst50: We have heard from the top executives of the company, who should have known better, a forth terminal was even required, …

As far as I know, it was clear right from the beginning that a forth terminal was needed for high-speed operation of the VCSEL. However, they underestimated the effort it would take to integrate that terminal monolithically.

As Fairchij already pointed out, each iteration in trying out yet another approach costs a six-digit amount of dollars. POET Technologies simply does not have that money at this time, so that project has to linger on the shelf until the financial situation changes for the better, e.g., by a strategic partner like India.

Bottom line: It can be done, but not right now.