The Photonic Fabric has to utilize the smallest node available because of the neuromorphic computing capabilities required to create the massive scale of chip to chip and within chip data processing. 

Poet’s optical engines are measured in millimeters vs nanometers by TSMC. 

The author has apparently confused node size on the electrical side with node requirements on the photonic side. Single mode fiber core is about 9000 nanometers thus the waveguides are required to be very large to enable very low loss coupling and transmission.

The material loss through the waveguides characterized by prism spectroscopy is <0.3dB/cm and is about one order of magnitude better than typically observed in small core silicon waveguides used in most other silicon photonics technologies. Moreover, our waveguides are largely athermal (dn/dT=12pm/°C) and are non-birefringent. A proprietary Spot Size Converter has been designed for chip facet fiber coupling achieving facet coupling losses of 0.25dB

https://poet-technologies.com/docs/presentations/VLSI-IEEE%20Symposium%20Accepted%20Paper%20on%20Wafer-Scale%20Hybrid%20Integration%20-%20June%2016%202022.pdf