DARPA’s HAPPI Program: The 1000× Leap Toward Fully Photonic Microsystem Connectivity

Introduction: From Electron Bottlenecks to Photonic Dominance For decades, the evolution of computing power has been framed as a story of shrinking transistors. Today, that narrative is breaking down. The limiting factor in advanced systems is no longer computation—it is the movement of data. As artificial intelligence models scale exponentially, sensor networks proliferate, and defense…