Development of new components and subsystems for a free space optical communications module in a silicon photonic platform

The growing demand for high-capacity, low-latency links for 5G/6G fronthaul and backhaul, data-center interconnects, and connectivity in spectrum-congested or defense and security-relevant scenarios is driving renewed interest in Free Space Optical Communications (FSOC). Despite their inherent advantages in bandwidth, security, and spectrum-free operation, widespread deployment of FSOC systems remains constrained by the limitations of conventional bulk-optics terminals, which are large, heavy, and costly, and rely on mechanically steered assemblies that increase maintenance requirements and limit long-term reliability. These characteristics hinder scalability and volume manufacturing, while preventing deployment on size, weight, and power-constrained platforms including mobile and compact terrestrial nodes. This work reviews the potential of photonic integrated circuits (PICs) to address these challenges by enabling compact, scalable, and highly functional on-chip FSOC transceivers. We illustrate how PIC technology enables the co-integration of key components and subsystems such as beam steering, wavefront sensing or adaptive signal processing which are essential for robust and resilient optical wireless links. As a representative example, we discuss recent Optical Phased Arrays (OPAs) developed by AGPhotonics, together with ongoing R&D efforts aimed at identifying the remaining technological gaps and defining a roadmap towards fully integrated, scalable FSOC terminals for terrestrial, aerial and space-based deployments.