Comment by prbs23

As others have said it's not the concept of DWDM that's new here. That has been around for a while. What is interesting here is that they have managed to integrate a DWDM transceiver onto a single silicon-photonic chip. As someone who has worked in similar silicon-photonic research, the challenge is to create the required filters, modulators, and demodulators that are stable enough over environmental conditions and manufacturing process variation for commercial production. Most silicon photonic structures are quite sensitive to temperature in particular.