In traditional switch hardware, data is sent over optical fibre using pluggable transceiver modules (SFP, QSFP, etc.) that slot into cages on the switch faceplate. These modules convert electrical signals from the switch ASIC into light and back, with each link carrying tens or hundreds of gigabits per second. Co-packaged optics (CPO) changes this paradigm by moving the photonic engines into the switch package itself. In a co-packaged design, the laser diodes, modulators and detectors are…