Photonic chip steers light over 1,300 km with less digital fixing

Researchers have experimentally reported 1,300-km transmission using a three-mode fibre, directly optimizing the spatial division multiplexed channel with programmable photonic processors. This approach shifts away from solely relying on digital equalization at the receiver, reducing the computational load needed for long-haul data transmission. The work demonstrates a telecom-grade programmable photonic unitary processor with high-fidelity operation, achieving R² greater than 96% across the C band, and establishes a scalable framework for integrating photonic computation into optical networks. The results offer a path toward more efficient, high-capacity systems needed to meet the demands of growing global data traffic. Parameterized spatial division multiplexed transmission uses…