Denselight is not a customer of POET

Denselight is a supplier of POET.

Denselight makes high-speed Directly Modulated Lasers (DML) that POET, by way of distributed feedback, is able to flip-chip onto the Optical Interposer platform, on their way to becoming an optical engine

 POET has also sought out other laser suppliers as well because Denselight, in it's present configuration, cannot meet the volume that POET anticipates will be required once production ramps up. 

IMO, of course