I'll take a stab, please add or correct as needed FJ and others. In short, POET can make significant amounts of product now.

POET has a foundry relationship with Silterra, in Malaysia, where the wafers are made. These are 8" wafers that are custom made using POET employees to maintain trade secrets in the foundry environment. The wafers are made with waveguides and other important features built in, and tested for defects while still in an 8" wafer format.

The wafers are shipped to Superphotonics (SPX), the JV with Sanan, a large chip maker in China. SPX is the site where the wafers are diced into OI and OE chips, and further process with the features needed. Lasers, modulators, photodiodes, and other items attached to the chip in a state of the art facility paid for by Sanan. 

I am not sure at what stage the "flip chip" attachment of these smaller parts takes place, I think it is at the SPX facility. 

There is a partnership with MultiLane, which has module making capacity. This may be more specialty product, not high volume, but I am only guessing. 

The buzz around here has been with who and when will the China +1 facility be announced to augment what SPX does. There is also a need at some point for another foundry service to address volume and cost issues. It has been discussed that a 12" wafer foundry is needed which, and means that about 2.25 times as many chips are made at one go vs. 8" wafers.

Mistubishi makes 12" wafers now for some products. Foxconn has announced that it will make wafers to service its AI chip partners. POET may fit into some of these plans.