Temporally plastic photonic processor for real-time adaptive computing.

Real-time intelligent systems increasingly require hardware that can adapt continuously to evolving inputs, yet most existing processors rely on static-weight inference, making them vulnerable to distribution shifts and error accumulation in dynamic environments. Although adaptive weight updates can, in principle, address this limitation, their implementation on electronic hardware is hindered by the stability-plasticity trade-off, as well as by the memory wall and clocking bottlenecks that become particularly severe in sequential processing. Here, we present a Temporally Plastic Photonic Processor (TPPP) that enables ultra-fast in situ adaptation by combining multi-timescale photonic kernels with a recursive optical delay memory. The architecture integrates a slow, reconfigurable kernel for stable long-term processing and a fast, dynamic kernel for transient adaptation, enabling time-varying weights to be embedded directly in the photonic domain without repeated electronic memory access. We experimentally validate the TPPP on linear and nonlinear sequential tasks. In both regimes, data-driven temporal plasticity enables the TPPP to outperform conventional static photonic baselines in robustness and accuracy. Under an operation-matched INT8 comparison, scaling analysis projects up to 16 × higher per-operation energy efficiency and up to 100 × lower intrinsic single-pass compute delay than advanced electronic processors, establishing the TPPP as a promising hardware framework for real-time adaptive photonic computing. Supplementary Information: The online version contains supplementary material available at 10.1186/s43593-026-00139-8.