Co-packaged optics

Placing optical transceivers inside the same package as a switch or processor chip, so data leaves the chip as light instead of over copper.

• Today, electrical signals cross several centimetres of circuit board to plug-in optical modules at the front of each switch.
• At 100+ gigabits per second per lane, copper degrades signals fast, and the circuitry that compensates burns a large share of the power.
• Converting to light millimetres from the chip can cut interconnect energy several-fold, vendors claim, and allows denser, longer links between racks.
• Lasers fail more often than silicon and are hard to service once sealed in, so many designs keep the laser in a separate replaceable module.