Light moves quickly enough to transmit enormous amounts of information, but that speed creates a problem when a computer needs to hold, delay, or synchronize an optical signal. Researchers from Seoul National University and the University of Seoul have now designed a programmable photonic integrated circuit that can slow light whenever needed.

The rapid growth of generative AI and large-scale artificial intelligence models has sharply increased computing demands. Conventional electronic semiconductors face persistent constraints, including heavy power use and limited data transfer speeds, driving interest in optical computing systems that process information rapidly with less energy. Yet because light naturally travels at a fixed speed, creating the buffers and memory functions needed for optical computing has remained difficult.

The researchers addressed this limitation with a programmable photonic circuit that controls both the speed and shape of optical signals. Their approach provided greater control over “slow light” than previously proposed methods.