Co-packaged optics (CPO)
Beginner
Putting the parts that send and catch light right next to the switch chip, instead of in plug-in modules at the front of the switch.
Novice
Optical engines mounted on the same package substrate as the switch chip, millimeters away from it. The electrical path is so short that the switch chip can use small, low-power SerDes and no DSP. Fibers run from the package to the front panel.
Expert
Optical engines (PIC + EIC) on the ASIC substrate, typically 3.2–6.4 Tb/s each, fed by external laser sources. Energy targets of 5–10 pJ/bit for the optics. Trades serviceability, test and supply-chain flexibility for power and density.
Explained in Optics (Systems).
See also: Optical engine, External laser source (ELS), Linear-drive pluggable optics (LPO).