POET Technologies Inc.

In the NR it says the following

Multiple 6-inch wafer lots of VCSELs and transistors were also processed at the foundry. Testing and characterization of these devices is underway and POET expects to require further development cycles through additional wafer processing to fully achieve the true potential for these integrated opto-electronic devices.

I know about the VCSELs but what transistors are they taliking about here?

Thanks

Trini