800G per fiber using POETs CWDM filtering capability combined with PAM4 DSP. 

 The advantage of a CPO solution is the 75-90% power reduction that results from placing the transceiver module in close proximity to the network switch ASIC itself, eliminating all the printed circuitry between the ASIC chip and the back of the box where the transceiver would normally be located. In this, POET has several advantages, including its ability to accurately place multiple lasers and modulators on a single substrate, to pull out the heat from those devices

 It is a solution that appears to be only achievable with the POET Optical Interface. Pretty clear to me that this kind of work can only be achieved by collaboration with an industry leader.