By "integration" I meant "turn the module into a chip" rather than "put the module in a phone" -- though your point about power could be the answer. Some lasers and optics just feel like the kind of thing that a clever team could squeeze onto a wafer, maybe with a loop in the third dimension. Or maybe just require two of them. There's probably a good answer as to why that's harder than it seems, I just don't know what it is.