Don't you think that Dr. Taylor did not think about the availability of Gallium, all ready.
If he went as was as develloping a new technologies that could revolutionnize the world, an doing it so with Galllium, i am pretty sure that he knows that stock won t ever be a factor.
So please stop wurrying about such questions like that.
If you are thinking about it now, i would imagine that POET's management has think about it a long, long time ago and that the availability of GaAs is not a problem.
IMO
Johny