Instead of piling on more laser wavelengths, the University of Washington uses microring modulators for coherent QAM, pushing a single wavelength to 320Gb/s at just 0.69pJ/b. RAMZI sidesteps MRM amplitude-phase coupling and time-multiplexed thermal tuning cuts the cost of thermal stability, delivering coherent, low-power and compact on low-cost 45nm silicon photonics.

2026 is the breakout year for 1.6T. Amid EML shortages and a split over the 3.2T path, Broadcom brought 50 million device-hours of CPO stability data, while Marvell and OpenLight showed breakthroughs in heterogeneous SiPh integration and coherent technology.