Monolithically silicon photonic integrated transceiver for microwave and optical dual-band beamforming and free-space communications

Future space-terrestrial networks demand integrated solutions combining the all-weather reliability of microwave communications with the ultra-high capacity of near-infrared optical links. However, monolithic integration of these complementary technologies, essential for compact and robust satellite payloads, remains a critical challenge. Here, we propose and experimentally demonstrate the world’s first monolithically integrated silicon photonic chip capable of microwave and near-infrared beamforming and dual-band free-space microwave and optical communications. The chip combines a microwave true time delay (TTD) beamforming network, an optical phased array (OPA) beamforming network, and an optical coherent transceiver. By integrating the high reliability of microwave communications, the wide bandwidth of near-infrared transmission, and the high sensitivity of optical coherent detection, this integrated circuit addresses key challenges in space-terrestrial networks, offering interference-resistant, high-capacity links for moving platforms. The chip is fabricated on a silicon-on-insulator (SOI) platform and experimentally evaluated. Experimental results demonstrate that the chip enables both microwave and optical two-dimensional dynamic beam steering, with microwave beam scanning over 24.9°×18.5° and optical beam scanning over 10°×4.7°. In a 5 m free-space communication link, it achieves error-free transmission at 10 Gb/s in the microwave band and 80 Gb/s per wavelength in the near-infrared band. The results validate the strong performance of the chip for dual-band microwave and optical communications.