With co-packaged optics, the channel length between the ASIC and the optical engine is up to 50mm and the channel loss is 10dB. With near package optics, the channel length is up to 150mm and a 13dB channel loss.

http://www.gazettabyte.com/home/2021/10/31/preparing-for-a-post-pluggable-optical-module-world.html

Is this something that POET would be able to improve upon?  POET improved spot-size converters to be able to match different modes of light beams for more efficient coupling between devices.  Theirs came in at <0.5 dB.

I've been looking around for a White Paper on the OIF ELSFP module initiative project and could not find anything. Probably still collecting data.  "The OIF’s ELSFP members have submitted technical contributions and a draft specification exists."

https://www.fibre-systems.com/news/three-projects-launched-oif