HAMON

HAMON: Passive diffractive optical system for long-horizon time-series forecasting

HAMON is a proposed forecasting architecture that replaces learned digital sequence-mixing layers with a passive diffractive optical core: historical values are encoded onto an optical aperture and cascaded trainable phase masks with free-space diffraction produce forecasts in the output field. At inference, prediction requires only a single passive optical propagation pass with no digital temporal mixing. The system outperforms strong digital baselines on ETTm2 and ETTh2 benchmarks by up to 14% MSE improvement, though it trails on high-channel-count datasets like Traffic and Electricity. The work raises a substrate-level question about whether forecasting operators need to be implemented digitally at all, and defines a concrete target for optical computing hardware.