AI designs ultracompact photonic components 500x smaller than engineers imagined

AI-driven inverse design shrank three photonic-chip components—mirrors, a wavelength splitter and a spatial mode sorter—by up to 500×, producing devices about 11 μm long for mirrors and ~5 μm for the splitter, made from silicon nitride (400–800 nm thick). The AI-optimized designs deliver strong light confinement and up to 98.5% reflectivity, demonstrating manufacturable, compact components that could boost on-chip performance for fiber-optic communications, data centers, AI, LiDAR and quantum computing.