3D Optoelectronics and Co-Packaged Optics: Innovations, Challenges, and Future Trends

Co-packaged optics (CPO) and three-dimensional (3D) optoelectronics represent a new frontier in high-speed data communication, targeting the rising demands for bandwidth, energy efficiency, and low latency in data centers, artificial intelligence (AI), and high-performance computing (HPC). This review examines the progression from pluggable optics to integrated photonic solutions, highlighting breakthroughs in silicon photonics, heterogeneous integration, and advanced packaging methods such as 2.5D interposers, Embedded Multi-die Inter- connect Bridge (EMIB), and 3D stacking. These innovations promise significant reductions in power consumption and notable gains in bandwidth density, yet thermal management, manufacturing yields, and alignment precision remain key challenges. Applications span hyperscale data centers, quantum networks, automotive lidar, and aerospace communications, illustrating the wide-reaching impact of these emerging technologies. The paper concludes by emphasizing future research directions and collaborative efforts needed to address remaining barriers and fully harness the transformative potential of integrated photonic- electronic systems.